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Liparoti S, Iozzino V, Speranza V, Pantani R. Modulating poly(lactic acid) degradation rate for environmentally sustainable applications. Waste Manag 2024; 175:215-224. [PMID: 38218092 DOI: 10.1016/j.wasman.2024.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/16/2023] [Accepted: 01/03/2024] [Indexed: 01/15/2024]
Abstract
The huge amount of plastics generated by the massive use of packaging makes it difficult to manage waste safely. Introducing biodegradable polymers, such as poly(lactic acid) (PLA), can at least partially reduce the environmental pollution from plastic waste. Biodegradable polymers must have a degradation rate appropriate for the intended use to replace durable plastics. This work aims to introduce PLA fillers that can modulate the degradation rate during hydrolysis and composting. For this purpose, fumaric acid and magnesium hydroxide have been proposed. The experimental findings demonstrated that magnesium oxide makes hydrolysis faster than fumaric acid. A model describing the hydrolysis reaction, which also considers the effect of crystallinity, is proposed. The model can capture the filler effect on the kinetic constants related to the autocatalytic part of the hydrolysis reaction. Degradation of the PLA and compounds was also conducted in a composting medium. The compound with fumaric acid shows faster degradation than the compound with magnesium oxide; this behavior is opposite to what is observed during hydrolysis. Degradation in a composting medium is favored in a narrow pH window corresponding to the optimum environment for microorganism growth. Magnesium oxide leads to a pH increase above the optimum level, making the environment less favorable to microorganism growth. Vice-versa, fumaric acid maintains the pH level in the optimum range: it represents an additional carbon source for microorganism growth.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132 Fisciano, SA, Italy.
| | - Valentina Iozzino
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132 Fisciano, SA, Italy
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132 Fisciano, SA, Italy
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132 Fisciano, SA, Italy
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2
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Liparoti S, Salomone R, Speranza V, Pantani R. Morphology Distribution in Injection Molded Parts. Polymers (Basel) 2024; 16:337. [PMID: 38337227 DOI: 10.3390/polym16030337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
A more sustainable use of plastic parts makes it necessary to replace current plastic parts with recyclable components, also allowing the modulation of the part properties through the process. Injection molding is one of the most widely used technologies for obtaining rigid plastic parts, so it is crucial to understand how to tailor properties by adopting the correct processing conditions. One way is to perform annealing steps directly inside the mold: in-mold annealing improves the structural integrity and durability of the material, reduces defects, increases the resistance of parts against certain chemicals, reduces wear and tear, increases ductility, and lowers brittleness. In this work, several in-mold annealing steps were conducted, changing the mold temperature and annealing duration selected on the basis of the half crystallization time of the adopted isotactic polypropylene. The typical molded part morphology, composed of oriented layers at the surface, transition zones, and spherulitic core, is strongly affected by in-mold annealing. In particular, the thickness of the oriented layer, which forms in the early phase of the process, decreases, and the spherulites increase in size. Concerning mechanical behavior, the orientation degree mostly determines the elastic modulus value close to the surface, whereas the conditions under which crystallization occurs determine the modulus in the core.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Rita Salomone
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy
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3
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Longo R, Vertuccio L, Speranza V, Pantani R, Raimondo M, Calabrese E, Guadagno L. Nanometric Mechanical Behavior of Electrospun Membranes Loaded with Magnetic Nanoparticles. Nanomaterials (Basel) 2023; 13:1252. [PMID: 37049345 PMCID: PMC10097362 DOI: 10.3390/nano13071252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 03/22/2023] [Accepted: 03/30/2023] [Indexed: 06/19/2023]
Abstract
This work analyzes on nanoscale spatial domains the mechanical features of electrospun membranes of Polycaprolactone (PCL) loaded with Functionalized Magnetite Nanoparticles (FMNs) produced via an electrospinning process. Thermal and structural analyses demonstrate that FMNs affect the PCL crystallinity and its melting temperature. HarmoniX-Atomic Force Microscopy (H-AFM), a modality suitable to map the elastic modulus on nanometric domains of the sample surface, evidences that the FMNs affect the local mechanical properties of the membranes. The mechanical modulus increases when the tip reveals the magnetite nanoparticles. That allows accurate mapping of the FMNs distribution along the nanofibers mat through the analysis of a mechanical parameter. Local mechanical modulus values are also affected by the crystallinity degree of PCL influenced by the filler content. The crystallinity increases for a low filler percentage (<5 wt.%), while, higher magnetite amounts tend to hinder the crystallization of the polymer, which manifests a lower crystallinity. H-AFM analysis confirms this trend, showing that the distribution of local mechanical values is a function of the filler amount and crystallinity of the fibers hosting the filler. The bulk mechanical properties of the membranes, evaluated through tensile tests, are strictly related to the nanometric features of the complex nanocomposite system.
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Affiliation(s)
- Raffaele Longo
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy; (R.L.); (V.S.); (R.P.); (M.R.); (E.C.)
| | - Luigi Vertuccio
- Department of Engineering, University of Campania “Luigi Vanvitelli”, Via Roma 29, 81031 Aversa, Italy;
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy; (R.L.); (V.S.); (R.P.); (M.R.); (E.C.)
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy; (R.L.); (V.S.); (R.P.); (M.R.); (E.C.)
| | - Marialuigia Raimondo
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy; (R.L.); (V.S.); (R.P.); (M.R.); (E.C.)
| | - Elisa Calabrese
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy; (R.L.); (V.S.); (R.P.); (M.R.); (E.C.)
| | - Liberata Guadagno
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy; (R.L.); (V.S.); (R.P.); (M.R.); (E.C.)
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Salomone R, Speranza V, Liparoti S, Titomanlio G, Pantani R. Modeling and Analysis of Morphology of Injection Molding Polypropylene Parts Induced by In-Mold Annealing. Polymers (Basel) 2022; 14:polym14235245. [PMID: 36501641 PMCID: PMC9740916 DOI: 10.3390/polym14235245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
It is generally recognized that high-temperature treatments, namely annealing, influence the microstructure and the morphology, which, in turn, determine the mechanical properties of polymeric parts. Therefore, annealing can be adopted to control the mechanical performance of the molded parts. This work aims to assess the effect of annealing on the morphology developed in isotactic polypropylene (iPP) injection-molded parts. In particular, a two-step annealing is adopted: the polymer is injected in a mold at a high temperature (413 or 433 K), which is kept for 5 min (first annealing step); afterward, the mold temperature is cooled down at 403 K and held at that temperature for a time compatible with the crystallization half-time at that temperature (second annealing step). The characterization of morphology is carried out by optical and electronic scanning microscopy. The temperature of the first annealing step does not influence the thickness of the fibrillar skin layer; however, such a layer is thinner than that found in the molded parts obtained without any annealing steps. The second annealing step does not influence the thickness of the fibrillar skin layer. The dimension of spherulites found in the core is strongly influenced by both annealing steps: the spherulite dimensions enlarge by the effect of annealing steps. A model that considers spherulite and fibril evolutions is adopted to describe the effect of molding conditions on the final morphology distribution along the part thickness. The model, which adopts as input the thermo-mechanical histories calculated by commercial software for injection molding simulation, consistently predicts the main effects of the molding conditions on the morphology distributions.
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Volpe V, Speranza V, Schrank T, Berer M, Pantani R. An investigation of crystallization kinetics of polyoxymethylene in processing conditions. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Valentina Volpe
- Department of Industrial Engineering University of Salerno Fisciano Italy
| | - Vito Speranza
- Department of Industrial Engineering University of Salerno Fisciano Italy
| | - Theresia Schrank
- Engineering Thermoplastics Polymer Competence Center Leoben GmbH Leoben Austria
| | - Michael Berer
- Engineering Thermoplastics Polymer Competence Center Leoben GmbH Leoben Austria
| | - Roberto Pantani
- Department of Industrial Engineering University of Salerno Fisciano Italy
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Liparoti S, Speranza V, Pantani R, Titomanlio G. Multi-Scale Simulation of Injection Molding Process with Micro-Features Replication: Relevance of Rheological Behaviour and Crystallization. Polymers (Basel) 2021; 13:polym13193236. [PMID: 34641052 PMCID: PMC8512435 DOI: 10.3390/polym13193236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/11/2021] [Accepted: 09/15/2021] [Indexed: 11/25/2022] Open
Abstract
The possibility of tailoring key surface properties through the injection molding process makes it intriguing from the perspective of sustainability enhancement. The surface properties depend on the replication accuracy of micro and nanostructures on moldings; such an accuracy is enhanced with cavity temperature. The simulation of the injection molding process is very challenging in the presence of micro and nanostructures on the cavity surface; this does not allow for the neglect of phenomena generally considered not to influence the overall process. In this paper, a multiscale approach was proposed: in the first step, the simulation of the overall process was conducted without considering the presence of the microstructure; in the second step the outputs of the first step were used as an input to simulate the replication of the microfeature. To this purpose, a lubrication approximation was adopted, and the contribution of the trapped air, which slows down the polymer advancement, was accounted for. A modification of the viscosity equation was also proposed to describe the rheological behavior of isotactic polypropylene at very low temperatures. Concerning the microcavity filling simulation, the modification of the viscosity description at low temperatures consistently describes the process, in terms of polymer solidification. Concerning the replication accuracy, it increases with the cavity surface temperature, consistently with the experimental observations.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy; (S.L.); (R.P.)
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy; (S.L.); (R.P.)
- Correspondence:
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, SA, Italy; (S.L.); (R.P.)
| | - Giuseppe Titomanlio
- Institute of Polymers, Composites and Biomaterials (IPCB), The National Research Council, Via Previati 1/C, 23900 Lecco, LC, Italy;
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Liparoti S, Sorrentino A, Speranza V. Morphology-Mechanical Performance Relationship at the Micrometrical Level within Molded Polypropylene Obtained with Non-Symmetric Mold Temperature Conditioning. Polymers (Basel) 2021; 13:462. [PMID: 33572694 PMCID: PMC7867022 DOI: 10.3390/polym13030462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 11/28/2022] Open
Abstract
The control of the structural properties of a polymeric material at the micro and nano-metrical scale is strategic to obtaining parts with high performance, durability and free from sudden failures. The characteristic skin-core morphology of injection molded samples is intimately linked to the complex shear flow, pressure and temperature evolutions experienced by the polymer chains during processing. An accurate analysis of this morphology can allow for the assessment of the quality and confidence of the process. Non-symmetric mold temperature conditions are imposed to produce complex morphologies in polypropylene parts. Morphological and micromechanical characterizations of the samples are used to quantify the effects of the processing conditions on the part performance. Asymmetric distribution of temperatures determines asymmetric distribution of both morphology and mechanical properties. The inhomogeneity degree depends on the time that one side of the cavity experiences high temperatures. The spherulites, which cover the thickest of the parts obtained with high temperatures at one cavity side, show smaller values of elastic modulus than the fibrils. When the polymer molecules experience high temperatures for long periods, the solid-diffusion and the partial melting and recrystallization phenomena determine a better structuring of the molecules with a parallel increase of the elastic modulus.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy;
| | - Andrea Sorrentino
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), Via Previati, 1/C, 23900 Lecco, Italy
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy;
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8
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Liparoti S, Speranza V, Marra F. Alginate hydrogel: The influence of the hardening on the rheological behaviour. J Mech Behav Biomed Mater 2021; 116:104341. [PMID: 33486329 DOI: 10.1016/j.jmbbm.2021.104341] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/04/2021] [Accepted: 01/15/2021] [Indexed: 12/19/2022]
Abstract
Alginate based gels are widely adopted in many pharmaceutical and biomedical fields. The main rheological characteristics of the alginate-based gels are important design parameters for gel preparation. A new methodology for rheological tests on the alginate-based gels has been assessed in order to obtain reliable and reproducible results in terms of loss and storage moduli. The methodology accounts for the effect of morphology on the rheological properties. Reliable results can be achieved if the structure of the gel is preserved during the analysis, thus, the control of the load applied during the rheological test plays a crucial role. The application of the proposed methodology allows to obtain information about the cross-linking degree of hydrogels. To this purpose, hydrogels with different ratios of divalent cations and alginate have been adopted. The number of junctions in the network formed during the cross-linking process has been evaluated and the results are consistent with the infrared analysis conducted on the same hydrogels.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering of the University of Salerno, via Giovanni Paolo II, 132, Fisciano, SA, Italy.
| | - Vito Speranza
- Department of Industrial Engineering of the University of Salerno, via Giovanni Paolo II, 132, Fisciano, SA, Italy
| | - Francesco Marra
- Department of Industrial Engineering of the University of Salerno, via Giovanni Paolo II, 132, Fisciano, SA, Italy
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Speranza V, Liparoti S, Pantani R. A method to obtain the quantitative orientation of semicrystalline structures in polymers by atomic force microscopy. EXPRESS POLYM LETT 2021. [DOI: 10.3144/expresspolymlett.2021.90] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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10
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Liparoti S, Speranza V, De Meo A, De Santis F, Pantani R. Prediction of the maximum flow length of a thin injection molded part. Journal of Polymer Engineering 2020. [DOI: 10.1515/polyeng-2019-0292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractOne of the most significant issues, when thin parts have to be obtained by injection molding (i.e. in micro-injection molding), is the determination of the conditions of pressure, mold temperature, and injection temperature to adopt to completely fill the cavity. Obviously, modern computational methods allow the simulation of the injection molding process for any material and any cavity geometry. However, this simulation requires a complete characterization of the material for what concerns the rheological and thermal parameters, and also a suitable criterion for solidification. These parameters are not always easily reachable. A simple test aimed at obtaining the required parameters is then highly advantageous. The so-called spiral flow test, consisting of measuring the length reached by a polymer in a long cavity under different molding conditions, is a method of this kind. In this work, with reference to an isotactic polypropylene, some spiral flow tests obtained with different mold temperatures and injection pressures are analyzed with a twofold goal: on one side, to obtain from a few simple tests the basic rheological parameters of the material; on the other side, to suggest a method for a quick prediction of the final flow length.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
| | - Annarita De Meo
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
| | | | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
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Speranza V, Liparoti S, Volpe V, Titomanlio G, Pantani R. Modelling of morphology development towards spherulites and shish–kebabs: Application to isothermal flow-induced crystallization experiments on isotactic polypropylene. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122459] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Speranza V, Liparoti S, Pantani R, Titomanlio G. Correction: Speranza, V. et al. Hierarchical Structure of iPP During Injection Molding Process with Fast Mold Temperature Evolution. Materials 2019, 12, 424. Materials (Basel) 2020; 13:ma13061277. [PMID: 32168982 PMCID: PMC7142452 DOI: 10.3390/ma13061277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 03/09/2020] [Indexed: 06/10/2023]
Abstract
The correction reported in the following has to be applied to the paper [...].
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Liparoti S, Speranza V, Titomanlio G, Pantani R. Effect of Rapid Mold Heating on the Structure and Performance of Injection-Molded Polypropylene. Polymers (Basel) 2020; 12:polym12020341. [PMID: 32033359 PMCID: PMC7077433 DOI: 10.3390/polym12020341] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/20/2020] [Accepted: 01/23/2020] [Indexed: 12/03/2022] Open
Abstract
The tailoring by the process of the properties developed in the plastic objects is the more effective way to improve the sustainability of the plastic objects. The possibility to tailor to the final use the properties developed within the molded object requires further understanding of the relationship between the properties of the plastic objects and the process conduction. One of the main process parameters that allow adjusting the properties of molded objects is the mold temperature. In this work, a thin electrical heater was located below the cavity surface in order to obtain rapid and localized surface heating/cooling cycles during the injection molding process. An isotactic polypropylene was adopted for the molding tests, during which surface temperature was modulated in terms of values and heating times. The modulation of the cavity temperature was found able to control the distribution of relevant morphological characteristics, thus, properties along the sample thickness. In particular, lamellar thickness, crystallinity distribution, and orientation were analyzed by synchrotron X-ray experiments, and the morphology and elastic modulus were characterized by atomic force microscopy acquisitions carried out with a tool for the simultaneous nanomechanical characterization. The crystalline degree slightly increased with the cavity temperature, and this induced an increase in the elastic modulus when high temperatures were adopted for the cavity surface. The cavity temperature strongly influenced the orientation distribution that, on its turn, determined the highest values of the elastic modulus found in the shear layer. Furthermore, although the sample core, not experiencing a strong flow field, was not characterized by high levels of orientation, it might show high values of the elastic modulus if temperature and time during crystallization were sufficient. In particular, if the macromolecules spent adequate time at temperatures close to the crystallization temperature, they could achieve high levels of structuring and, thus, high values of elastic modulus.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132-84084 Fisciano (SA), Italy; (S.L.); (G.T.); (R.P.)
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132-84084 Fisciano (SA), Italy; (S.L.); (G.T.); (R.P.)
- Correspondence:
| | - Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132-84084 Fisciano (SA), Italy; (S.L.); (G.T.); (R.P.)
- Institute of Polymers, Composites and Biomaterials (IPCB), The National Research Council (Cnr), Via Previati 1/C, 23900 Lecco (LC), Italy
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132-84084 Fisciano (SA), Italy; (S.L.); (G.T.); (R.P.)
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14
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Buonerba A, Monica FD, Speranza V, Capacchione C, Milione S, Grassi A. Thin‐film nanostructure and polymer architecture in semicrystalline syndiotactic poly(
p
‐methylstyrene)–(
cis
‐1,4‐polybutadiene) multiblock copolymers. POLYM INT 2019. [DOI: 10.1002/pi.5871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Antonio Buonerba
- Dipartimento di Chimica e Biologia ‘Adolfo Zambelli’Università degli Studi di Salerno Fisciano Italy
| | - Francesco Della Monica
- Dipartimento di Chimica e Biologia ‘Adolfo Zambelli’Università degli Studi di Salerno Fisciano Italy
| | - Vito Speranza
- Dipartimento di Ingegneria IndustrialeUniversità degli Studi di Salerno Fisciano Italy
| | - Carmine Capacchione
- Dipartimento di Chimica e Biologia ‘Adolfo Zambelli’Università degli Studi di Salerno Fisciano Italy
| | - Stefano Milione
- Dipartimento di Chimica e Biologia ‘Adolfo Zambelli’Università degli Studi di Salerno Fisciano Italy
| | - Alfonso Grassi
- Dipartimento di Chimica e Biologia ‘Adolfo Zambelli’Università degli Studi di Salerno Fisciano Italy
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15
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Lamparelli DH, Speranza V, Camurati I, Buonerba A, Oliva L. Synthesis and Characterization of Syndiotactic Polystyrene-Polyethylene Block Copolymer. Polymers (Basel) 2019; 11:polym11040698. [PMID: 30995818 PMCID: PMC6523272 DOI: 10.3390/polym11040698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 11/23/2022] Open
Abstract
The direct synthesis of syndiotactic polystyrene-block-polyethylene copolymer (sPS-b-PE) with a diblock structure has been achieved. The synthetic strategy consists of the sequential stereocontrolled polymerization of styrene and ethylene in the presence of a single catalytic system: cyclopentadienyltitanium(IV) trichloride activated by modified methylaluminoxane (CpTiCl3/MMAO). The reaction conditions suitable for affording the partially living polymerization of these monomers were identified, and the resulting copolymer, purified from contaminant homopolymers, was fully characterized. Gel permeation chromatography coupled with two-dimensional NMR spectroscopy COSY, HSQC, and DOSY confirmed the block nature of the obtained polymer, whose thermal behaviour and thin film morphology were also investigated by differential scanning calorimetry, powder wide angle x-ray diffraction, and atomic force microscopy.
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Affiliation(s)
- David Hermann Lamparelli
- Dipartimento di Chimica e Biologia "Adolfo Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano (SA), Italy.
| | - Vito Speranza
- Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano (SA), Italy.
| | - Isabella Camurati
- Centro Ricerche G. Natta, Basell Polyolefins, P.le G. Donegani 12, I-44100 Ferrara, Italy.
| | | | - Leone Oliva
- Dipartimento di Chimica e Biologia "Adolfo Zambelli", Università degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano (SA), Italy.
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16
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Titomanlio G, Speranza V. Polymer Processing: Modeling and Correlations Finalized to Tailoring Plastic Part Morphology and Properties. Materials (Basel) 2019; 12:ma12081217. [PMID: 31013956 PMCID: PMC6515399 DOI: 10.3390/ma12081217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/28/2019] [Accepted: 04/09/2019] [Indexed: 12/03/2022]
Abstract
The analysis of polymer processing operations requires the description of simultaneous transient momentum and heat transfer down to material solidification. The aim of the analysis is to improve and, hopefully, optimize the final properties that are determined by the final morphology of the part. In this special issue, consisting of 1 review and 11 research articles detailing several polymer processing operations, experimental and numerical analyses have been conducted in order to identify and describe the main relevant phenomena, that affect the product morphologies and properties.
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Affiliation(s)
- Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
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Guadagno L, Naddeo C, Raimondo M, Speranza V, Pantani R, Acquesta A, Carangelo A, Monetta T. UV Irradiated Graphene-Based Nanocomposites: Change in the Mechanical Properties by Local HarmoniX Atomic Force Microscopy Detection. Materials (Basel) 2019; 12:E962. [PMID: 30909458 PMCID: PMC6470810 DOI: 10.3390/ma12060962] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 03/12/2019] [Accepted: 03/19/2019] [Indexed: 11/17/2022]
Abstract
Epoxy based coatings are susceptible to ultra violet (UV) damage and their durability can be significantly reduced in outdoor environments. This paper highlights a relevant property of graphene-based nanoparticles: Graphene Nanoplatelets (GNPs) incorporated in an epoxy-based free-standing film determine a strong decrease of the mechanical damages caused by UV irradiation. The effects of UV light on the morphology and mechanical properties of the solidified nanocharged epoxy films are investigated by Atomic Force Microscopy (AFM), in the acquisition mode "HarmoniX." Nanometric-resolved maps of the mechanical properties of the multi-phase material evidence that the incorporation of low percentages, between 0.1% and 1.0% by weight, of graphene nanoplatelets (GNPs) in the polymeric film causes a relevant enhancement in the mechanical stability of the irradiated films. The beneficial effect progressively increases with increasing GNP percentage. The paper also highlights the potentiality of AFM microscopy, in the acquisition mode "HarmoniX" for studying multiphase polymeric systems.
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Affiliation(s)
- Liberata Guadagno
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, Salerno, 84084 Fisciano, Italy.
| | - Carlo Naddeo
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, Salerno, 84084 Fisciano, Italy.
| | - Marialuigia Raimondo
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, Salerno, 84084 Fisciano, Italy.
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, Salerno, 84084 Fisciano, Italy.
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, Salerno, 84084 Fisciano, Italy.
| | - Annalisa Acquesta
- Department of Chemical Engineering, Materials and Industrial Production, University of Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy.
| | - Anna Carangelo
- Department of Chemical Engineering, Materials and Industrial Production, University of Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy.
| | - Tullio Monetta
- Department of Chemical Engineering, Materials and Industrial Production, University of Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy.
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Liparoti S, Speranza V, Pantani R, Titomanlio G. Process Induced Morphology Development of Isotactic Polypropylene on the Basis of Molecular Stretch and Mechanical Work Evolutions. Materials (Basel) 2019; 12:ma12030505. [PMID: 30736398 PMCID: PMC6384558 DOI: 10.3390/ma12030505] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/03/2019] [Accepted: 02/05/2019] [Indexed: 11/28/2022]
Abstract
It is well known that under high shear rates polymers tend to solidify with formation of morphological elements oriented and aligned along the flow direction. On the other hand, stretched polymer chains may not have sufficient time to undergo the structuring steps, which give rise to fibrillar morphology. In the last decades, several authors have proposed a combined criterion based on both a critical shear rate and a critical mechanical work, which guaranties adequate time for molecular structuring. In this paper, the criterion, reformulated on the basis of critical values of both molecular stretch and mechanical work and adjusted to account for the unsteady character of the polymer processing operations, is applied to the analysis of a set of isotactic polypropylene injection molded samples obtained under very different thermal boundary conditions. The evolutions of molecular stretch and mechanical work are evaluated using process simulation. The results of the model reproduce the main characteristics of the morphology distribution detected on the cross sections of moldings, obtained under very different thermal boundary conditions, assuming that the critical work is a function of temperature.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno-via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno-via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno-via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno-via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
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Speranza V, Liparoti S, Pantani R, Titomanlio G. Hierarchical Structure of iPP During Injection Molding Process with Fast Mold Temperature Evolution. Materials (Basel) 2019; 12:E424. [PMID: 30704102 PMCID: PMC6384804 DOI: 10.3390/ma12030424] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 01/23/2019] [Accepted: 01/25/2019] [Indexed: 11/24/2022]
Abstract
Mold surface temperature strongly influences the molecular orientation and morphology developed in injection molded samples. In this work, an isotactic polypropylene was injected into a rectangular mold, in which the cavity surface temperature was properly modulated during the process by an electrical heating device. The induced thermo-mechanical histories strongly influenced the morphology developed in the injection molded parts. Polarized optical microscope and atomic force microscope were adopted for morphological investigations. The combination of flow field and cooling rate experienced by the polymer determined the hierarchical structure. Under strong flow fields and high temperatures, a tightly packed structure, called shish-kebab, aligned along the flow direction, was observed. Under weak flow fields, the formation of β-phase, as cylindrites form, was observed. The formation of each morphological structure was analyzed and discussed on the bases of the flow and temperature fields, experienced by the polymer during each stage of the injection molding process.
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Affiliation(s)
- Vito Speranza
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Sara Liparoti
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
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Liparoti S, Speranza V, Pantani R. Replication of Micro- and Nanofeatures in Injection Molding of Two PLA Grades with Rapid Surface-Temperature Modulation. Materials (Basel) 2018; 11:E1442. [PMID: 30111736 PMCID: PMC6119903 DOI: 10.3390/ma11081442] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 08/07/2018] [Accepted: 08/09/2018] [Indexed: 11/16/2022]
Abstract
The production by injection molding of polymeric components having micro- and nanometrical surfaces is a complex task. Generally, the accurate replication of micro- and nanometrical features on the polymeric surface during the injection-molding process is prevented by of the low mold temperature adopted to reduce cooling time. In this work, we adopt a system that allows fast heating of the cavity surface during the time the melt reaches the cavity, and fast cooling after heater deactivation. A nickel insert with micro- and nanofeatures in relief is located on the cavity surface. Replication accuracy is analyzed by Atomic Force Microscopy under different injection-molding conditions. Two grades of polylactic acid with different viscosity have been adopted. The results indicate that the higher the cavity surface temperature is, the higher the replication accuracy is. The viscosity has a significant effect only in the replication of the microfeatures, whereas its effect results are negligible in the replication of nanofeatures, thus suggesting that the interfacial phenomena are more important for replication at a nanometric scale. The evolution of the crystallinity degree on the surface also results in a key factor on the replication of nanofeatures.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno⁻via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
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Abstract
Abstract
It is quite well known that the morphology of an injection molded part made by a semicrystalline polymer presents several layers. In particular spherulitic structures are found in the core region, a layer characterized by highly oriented fibrillar morphology (the shear layer) usually follows and a skin layer is often observed at the sample surface. The thickness of the fibrillar layer deeply influences the mechanical properties of the part. In this work, a criterion to predict the thickness of the fibrillar layer is proposed and verified. The criterion is essentially based on the amount of viscous work done when the molecular stretch is higher than a critical value: the molecular stretch should be above a critical value while a critical amount of viscous work is accumulated. In order to tune the parameters, and to validate the criterion, a well characterized polypropylene was chosen as test material, and four different injection molding conditions were analyzed. The criterion is verified by comparing some experimental results with the prediction of the UNISA code (an injection molding software developed at the University of Salerno), good comparison between software predictions and experimental data confirms the suitability of the criterion.
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Affiliation(s)
- R. Pantani
- Department of Industrial Engineering , University of Salerno, Fisciano (SA) , Italy
| | - V. Speranza
- Department of Industrial Engineering , University of Salerno, Fisciano (SA) , Italy
| | - G. Titomanlio
- Department of Industrial Engineering , University of Salerno, Fisciano (SA) , Italy
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Liparoti S, Pantani R, Sorrentino A, Speranza V, Titomanlio G. Hydrophobicity Tuning by the Fast Evolution of Mold Temperature during Injection Molding. Polymers (Basel) 2018; 10:E322. [PMID: 30966357 PMCID: PMC6415138 DOI: 10.3390/polym10030322] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 02/26/2018] [Accepted: 03/09/2018] [Indexed: 01/06/2023] Open
Abstract
The surface topography of a molded part strongly affects its functional properties, such as hydrophobicity, cleaning capabilities, adhesion, biological defense and frictional resistance. In this paper, the possibility to tune and increase the hydrophobicity of a molded polymeric part was explored. An isotactic polypropylene was injection molded with fast cavity surface temperature evolutions, obtained adopting a specifically designed heating system layered below the cavity surface. The surface topology was characterized by atomic force microscopy (AFM) and, concerning of hydrophobicity, by measuring the water static contact angle. Results show that the hydrophobicity increases with both the temperature level and the time the cavity surface temperature was kept high. In particular, the contact angle of the molded sample was found to increase from 90°, with conventional molding conditions, up to 113° with 160 °C of cavity surface temperature kept for 18 s. This increase was found to be due to the presence of sub-micro and nano-structures characterized by high values of spatial frequencies which could be more accurately replicated by adopting high heating temperatures and times. The surface topography and the hydrophobicity resulted therefore tunable by selecting appropriate injection molding conditions.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, via G. Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, via G. Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Andrea Sorrentino
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), via Previati n. 1/E, 23900 Lecco, Italy.
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via G. Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno, via G. Paolo II 132, 84084 Fisciano (SA), Italy.
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Buonerba A, Speranza V, Capacchione C, Milione S, Grassi A. Improvement of tensile properties, self-healing and recycle of thermoset styrene/2-vinylfuran copolymers via thermal triggered rearrangement of covalent crosslink. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2017.12.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Pantani R, Speranza V, Titomanlio G. Effect of flow-induced crystallization on the distribution of spherulite dimensions along cross section of injection molded parts. Eur Polym J 2017. [DOI: 10.1016/j.eurpolymj.2017.10.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Liparoti S, Speranza V, Sorrentino A, Titomanlio G. Mechanical Properties Distribution within Polypropylene Injection Molded Samples: Effect of Mold Temperature under Uneven Thermal Conditions. Polymers (Basel) 2017; 9:E585. [PMID: 30965891 PMCID: PMC6418651 DOI: 10.3390/polym9110585] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/01/2017] [Accepted: 11/03/2017] [Indexed: 11/17/2022] Open
Abstract
The quality of the polymer parts produced by injection molding is strongly affected by the processing conditions. Uncontrolled deviations from the proper process parameters could significantly affect both internal structure and final material properties. In this work, to mimic an uneven temperature field, a strong asymmetric heating is applied during the production of injection-molded polypropylene samples. The morphology of the samples is characterized by optical and atomic force microscopy (AFM), whereas the distribution of mechanical modulus at different scales is obtained by Indentation and HarmoniX AFM tests. Results clearly show that the temperature differences between the two mold surfaces significantly affect the morphology distributions of the molded parts. This is due to both the uneven temperature field evolutions and to the asymmetric flow field. The final mechanical property distributions are determined by competition between the local molecular stretch and the local structuring achieved during solidification. The cooling rate changes affect internal structures in terms of relaxation/reorganization levels and give rise to an asymmetric distribution of mechanical properties.
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Affiliation(s)
- Sara Liparoti
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
| | - Andrea Sorrentino
- Institute for Polymers, Composites and Biomaterials (IPCB-CNR), Via Previati, 1/C, 23900 Lecco, Italy.
| | - Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
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Pantani R, Speranza V, Titomanlio G. Thirty Years of Modeling of Injection Molding. A Brief Review of the Contribution of UNISA Code to the Field. INT POLYM PROC 2016. [DOI: 10.3139/217.3249] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
UNISA code, a software for the analysis and modeling of injection molding, was born at the University of Palermo in Italy in the 1980s. Afterwards, in the 1990s, it was rewritten and expanded at the University of Salerno (Italy) and continuously improved over the years. It is a study code, aimed at understanding rather than simulating. It has the unique characteristic of describing, since the early versions, the morphology of the molded samples. Furthermore, it always implemented the interrelationships among the different material properties (crystallinity, viscosity, density). In this work, the evolution of the software is reviewed, placed in the background, underlining the contribution given to the understanding of polymer processing and morphology evolution. Eventually, the future challenges of modeling are presented.
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Affiliation(s)
- R. Pantani
- Department of Industrial Engineering , University of Salerno, Fisciano (SA) , Italy
| | - V. Speranza
- Department of Industrial Engineering , University of Salerno, Fisciano (SA) , Italy
| | - G. Titomanlio
- Department of Industrial Engineering , University of Salerno, Fisciano (SA) , Italy
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Yamada A, Ischenko M, Walters D, Hamilton-Craig C, Platts D, Speranza V, Benjamin A, Harten M, Burstow D, Chan J. Short-term effects of transcatheter aortic valve implantation on left ventricular transmural mechanics using multi-layer speckle tracking echocardiography. Heart Lung Circ 2015. [DOI: 10.1016/j.hlc.2015.06.584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Buonerba A, Speranza V, Canton P, Capacchione C, Milione S, Grassi A. Novel nanostructured semicrystalline ionomers by chemoselective sulfonation of multiblock copolymers of syndiotactic polystyrene with polybutadiene. RSC Adv 2014. [DOI: 10.1039/c4ra13253j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Affiliation(s)
- Roberto Pantani
- Department of Chemical and Food Engineering; University of Salerno; via Giovanni Paolo II I-84084 Fisciano Salerno Italy
| | - Vito Speranza
- Department of Chemical and Food Engineering; University of Salerno; via Giovanni Paolo II I-84084 Fisciano Salerno Italy
| | - Giuseppe Titomanlio
- Department of Chemical and Food Engineering; University of Salerno; via Giovanni Paolo II I-84084 Fisciano Salerno Italy
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Capacchione C, De Roma A, Buonerba A, Speranza V, Milione S, Grassi A. Syndiotactic Polystyrene-block
-Poly(methyl methacrylate) Copolymer via Click Chemistry. MACROMOL CHEM PHYS 2013. [DOI: 10.1002/macp.201300237] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
Abstract
Modelling of the injection moulding process is carried out in this work on the basis of Williams and Lord model and its recent extensions to post filling stages. The emphasis is devoted to identifying the role of crystallisation kinetics in the process simulation. Data of pressure histories during injection moulding of an iPP are taken as reference to the analysis. Crystallisation kinetics of the material was described by means of a non-isothermal formulation of Avrami model whose parameters where determined either by accounting for only of calorimetric results or by describing also final density data of thin samples subjected to characterised quenching histories. Predictions of pressure histories are analysed in relation to the crystallisation kinetics adopted. The effect of pressure on crystallisation is also discussed.
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Affiliation(s)
- R. Pantani
- Department of Chemical and Food Engineering, University of Salerno, Fisciano (Salerno), Italy
| | - V. Speranza
- Department of Chemical and Food Engineering, University of Salerno, Fisciano (Salerno), Italy
| | - G. Titomanlio
- Department of Chemical and Food Engineering, University of Salerno, Fisciano (Salerno), Italy
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Abstract
Abstract
The relevance of enhancement of crystallisation kinetics by effect of shear flow and rheology during polymer solidification to the phenomena taking place during the injection moulding process has been shown by means of simulations performed on the basis of Lord and Williams [1, 2] model and its recent extensions [3 to 5]. A key point of the simulation was the solidification criterion based on a critical crystallization index; on the basis of simple calorimetric and rheological tests in the limit of zero shear rate, values of a few percent were given to the solidification crystallinity value.
Many experimental features of pressure history both in the runner and in the cavity are recovered by model predictions, if both effects mentioned above are properly accounted for. However, predictions for gate sealing time, although improved, still have a sensitivity to gate thickness lower than that shown by the experiments. Similar conclusions, obviously, regard also the mass entering in the mould during holding.
Another mechanism which sums up to shear stresses to accelerate thin gate solidification has still to be identified.
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Affiliation(s)
- G. Titomanlio
- Dipartimento di Ingegneria Chimica e Alimentare, Università di Salerno, Fisciano (Salerno), Italy
| | - V. Speranza
- Dipartimento di Ingegneria Chimica e Alimentare, Università di Salerno, Fisciano (Salerno), Italy
| | - V. Brucato
- Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Università di Palermo, Palermo, Italy
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Abstract
Abstract
Numerical simulation of the injection moulding process of thermoplastic polymers has been performed on the basis of the Williams and Lord model and its recent extensions. The aim of the simulation was to identify material properties which play a relevant role to process modelling, including post filling stages. Predictions improve significantly by taking into account the effect of pressure on both viscosity and crystallisation kinetics. Several features, however, are not satisfactorily predicted. Also the relevance of convection during packing has been evidenced especially with reference to gate sealing time. As highly oriented crystalline structures are present in the final moulded object, the enhancement of crystallisation kinetics by the effect of flow is suggested as the phenomenon to be accounted for in order to gain a quantitative description of the whole process.
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Affiliation(s)
- G. Titomanlio
- Dipartimento di Ingegneria Chimica e Alimentare, Universita’ di Salerno, Fisciano (Salerno), Italy
| | - V. Speranza
- Dipartimento di Ingegneria Chimica e Alimentare, Universita’ di Salerno, Fisciano (Salerno), Italy
| | - V. Brucato
- Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita’ di Palermo, Palermo, Italy
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Affiliation(s)
- Antonio Buonerba
- Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, via Ponte
don Melillo, 84084 Fisciano (SA), Italy
- NANOMATES, Research Centre for NANOMAterials and nanoTEchnology at Salerno University, 84084 Fisciano (SA), Italy
| | - Vito Speranza
- NANOMATES, Research Centre for NANOMAterials and nanoTEchnology at Salerno University, 84084 Fisciano (SA), Italy
- Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, via Ponte
don Melillo, 84084 Fisciano (SA), Italy
| | - Alfonso Grassi
- Dipartimento di Chimica e Biologia, Università degli Studi di Salerno, via Ponte
don Melillo, 84084 Fisciano (SA), Italy
- NANOMATES, Research Centre for NANOMAterials and nanoTEchnology at Salerno University, 84084 Fisciano (SA), Italy
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38
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Speranza V, Yamada A, Cafaro J, Ischenko M, Benjamin A, Harten M, Anderson B, Platts D, Hamilton-Craig C, Burstow D, Chan J. Assessment of Inter-observer Reproducibility of Left Ventricular Global Longitudinal Strain between an Expert and Novice Observer. Heart Lung Circ 2013. [DOI: 10.1016/j.hlc.2013.05.396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ischenko M, Yamada A, Cafaro J, Speranza V, Harten M, Benjamin A, Platts D, Hamilton-Craig C, Burstow D, Chan J. Evaluation of Inter-vendor Consistency and Reproducibility of Left Ventricular Two-dimensional Strain Measurements with Two Different High-end Ultrasound Systems. Heart Lung Circ 2013. [DOI: 10.1016/j.hlc.2013.05.422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Speranza V, Vietri U, Pantani R. Adopting the Experimental Pressure Evolution to Monitor Online the Shrinkage in Injection Molding. Ind Eng Chem Res 2012. [DOI: 10.1021/ie302432v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- V. Speranza
- Department of Industrial Engineering, University of Salerno,
via Ponte don Melillo, I-84084 Fisciano (SA), Italy
| | - U. Vietri
- Department of Industrial Engineering, University of Salerno,
via Ponte don Melillo, I-84084 Fisciano (SA), Italy
| | - R. Pantani
- Department of Industrial Engineering, University of Salerno,
via Ponte don Melillo, I-84084 Fisciano (SA), Italy
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Pantani R, Sorrentino A, Speranza V, Titomanlio G. Process-Induced Morphology Distribution in Injection Molded Syndiotactic Polystyrene Samples. Ind Eng Chem Res 2012. [DOI: 10.1021/ie301253v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roberto Pantani
- Department of Industrial Engineering, University of Salerno, via Ponte don Melillo, I-84084
Fisciano (Salerno), Italy
| | - Andrea Sorrentino
- Institute for Composite and
Biomedical Materials (IMCB), National Research Council (CNR), Piazzale Enrico Fermi 1, I-80055 Portici (NA),
Italy
| | - Vito Speranza
- Department of Industrial Engineering, University of Salerno, via Ponte don Melillo, I-84084
Fisciano (Salerno), Italy
| | - Giuseppe Titomanlio
- Department of Industrial Engineering, University of Salerno, via Ponte don Melillo, I-84084
Fisciano (Salerno), Italy
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Yamada A, Luis S, Sathianathan D, Ta’i S, Speranza V, Hourigan L, Haseler L, Burstow D, Chan J. Validation and Feasibility of 3 Dimensional Speckle Tracking Echocardiography to Quantify Left Ventricular Regional Deformation. Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.05.574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Speranza V, Vietri U, Pantani R. Monitoring of injection molding of thermoplastics: Average solidification pressure as a key parameter for quality control. Macromol Res 2011. [DOI: 10.1007/s13233-011-0610-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Santis FD, Pantani R, Speranza V, Titomanlio G. Analysis of Shrinkage Development of a Semicrystalline Polymer during Injection Molding. Ind Eng Chem Res 2010. [DOI: 10.1021/ie901316p] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Felice De Santis
- Department of Chemical and Food Engineering, University of Salerno, 84084 Fisciano (SA), Italy
| | - Roberto Pantani
- Department of Chemical and Food Engineering, University of Salerno, 84084 Fisciano (SA), Italy
| | - Vito Speranza
- Department of Chemical and Food Engineering, University of Salerno, 84084 Fisciano (SA), Italy
| | - Giuseppe Titomanlio
- Department of Chemical and Food Engineering, University of Salerno, 84084 Fisciano (SA), Italy
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Buonerba A, Cuomo C, Speranza V, Grassi A. Crystalline Syndiotactic Polystyrene as Reinforcing Agent of cis-1,4-Polybutadiene Rubber. Macromolecules 2009. [DOI: 10.1021/ma901859e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Antonio Buonerba
- Dipartimento di Chimica, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
- NANOMATES, Research Centre for NANOMAterials and nanoTEchnology at Salerno University, 84084 Fisciano (SA), Italy
| | - Cinzia Cuomo
- Dipartimento di Chimica, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
- NANOMATES, Research Centre for NANOMAterials and nanoTEchnology at Salerno University, 84084 Fisciano (SA), Italy
| | - Vito Speranza
- Dipartimento di Ingegneria Chimica, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
| | - Alfonso Grassi
- Dipartimento di Chimica, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy
- NANOMATES, Research Centre for NANOMAterials and nanoTEchnology at Salerno University, 84084 Fisciano (SA), Italy
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Speranza V, Pantani R, Besana G, Titomanlio G. Anisotropic shrinkage of injection molded poly vinylidene fluoride samples. POLYM ENG SCI 2007. [DOI: 10.1002/pen.20878] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Pantani R, Coccorullo I, Speranza V, Titomanlio G. Modeling of morphology evolution in the injection molding process of thermoplastic polymers. Prog Polym Sci 2005. [DOI: 10.1016/j.progpolymsci.2005.09.001] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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