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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] [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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Murariu M, Laoutid F, Paint Y, Murariu O, Raquez JM, Dubois P. Balancing the Strength-Impact Relationship and Other Key Properties in Polypropylene Copolymer-Natural CaSO 4 (Anhydrite)-Filled Composites. Int J Mol Sci 2023; 24:12659. [PMID: 37628840 PMCID: PMC10454880 DOI: 10.3390/ijms241612659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/31/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023] Open
Abstract
To develop novel mineral-filled composites and assess their enhanced properties (stiffness, a good balance between mechanical strength and impact resistance, greater temperature stability), a high-impact polypropylene copolymer (PPc) matrix containing an elastomeric discrete phase was melt mixed with natural CaSO4 β-anhydrite II (AII) produced from gypsum rocks. First, in a prior investigation, the PPc composites filled with AII (without any modification) displayed enhanced stiffness, which is correlated with the relative content of the filler. The tensile and impact strengths dramatically decreased, especially at high filling (40 wt.%). Therefore, two key methods were considered to tune up their properties: (a) the ionomeric modification of PPc composites by reactive extrusion (REx) with zinc diacrylate (ZA), and (b) the melt mixing of PPc with AII surface modified with ethylenebis(stearamide) (EBS), which is a multifunctional processing/dispersant additive. The properties of composites produced with twin-screw extruders (TSEs) were deeply assessed in terms of morphology, mechanical, and thermal performance, including characterizations under dynamic mechanical solicitations at low and high temperatures. Two categories of products with distinct properties are obtained. The ionomeric modification by Rex (evaluated by FTIR) led to composites characterized by remarkable thermal stability, a higher temperature of crystallization, stronger interfacial interactions, and therefore noticeable mechanical properties (high tensile strength (i.e., 28 MPa), increased stiffness, moderate (3.3 kJ/m2) to good (5.0 kJ/m2) impact resistance) as well as advanced heat deflection temperature (HDT). On the other hand, the surface modification of AII with EBS facilitated the dispersion and debonding of microparticles, leading to composites revealing improved ductility (strain at break from 50% to 260%) and enhanced impact properties (4.3-5.3 kJ/m2), even at high filling. Characterized by notable mechanical and thermal performances, high whiteness, and a good processing ability, these new PPc-AII composites may be tailored to meet the requirements of end-use applications, ranging from packaging to automotive components.
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Affiliation(s)
- Marius Murariu
- Laboratory of Polymeric and Composite Materials, Materia Nova Materials R&D Center & UMONS Innovation Center, 3 Avenue Copernic, 7000 Mons, Belgium; (F.L.); (Y.P.); (O.M.)
- Laboratory of Polymeric and Composite Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons (UMONS), Place du Parc 20, 7000 Mons, Belgium;
| | - Fouad Laoutid
- Laboratory of Polymeric and Composite Materials, Materia Nova Materials R&D Center & UMONS Innovation Center, 3 Avenue Copernic, 7000 Mons, Belgium; (F.L.); (Y.P.); (O.M.)
| | - Yoann Paint
- Laboratory of Polymeric and Composite Materials, Materia Nova Materials R&D Center & UMONS Innovation Center, 3 Avenue Copernic, 7000 Mons, Belgium; (F.L.); (Y.P.); (O.M.)
| | - Oltea Murariu
- Laboratory of Polymeric and Composite Materials, Materia Nova Materials R&D Center & UMONS Innovation Center, 3 Avenue Copernic, 7000 Mons, Belgium; (F.L.); (Y.P.); (O.M.)
| | - Jean-Marie Raquez
- Laboratory of Polymeric and Composite Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons (UMONS), Place du Parc 20, 7000 Mons, Belgium;
| | - Philippe Dubois
- Laboratory of Polymeric and Composite Materials, Materia Nova Materials R&D Center & UMONS Innovation Center, 3 Avenue Copernic, 7000 Mons, Belgium; (F.L.); (Y.P.); (O.M.)
- Laboratory of Polymeric and Composite Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons (UMONS), Place du Parc 20, 7000 Mons, Belgium;
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Yang J, Liu X, Zhao J, Pu X, Shen Z, Xu W, Liu Y. The Structural Evolution of β-to- α Phase Transition in the Annealing Process of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Polymers (Basel) 2023; 15:polym15081921. [PMID: 37112068 PMCID: PMC10143349 DOI: 10.3390/polym15081921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/02/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
In this study, the structural and property changes induced in the highly ordered structure of preoriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) PHBV films containing the β-form during annealing were investigated. The transformation of the β-form was investigated by means of in situ wide-angle X-ray diffraction (WAXD) using synchrotron X-rays. The comparison of PHBV films with the β-form before and after annealing was performed using small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The evolution mechanism of β-crystal transformation was elucidated. It was revealed that most of the highly oriented β-form directly transforms into the highly oriented α-form, and there might be two kinds of transformations: (1) The β-crystalline bundles may be transformed one by one rather than one part by one part during annealing before a certain annealing time. (2) The β-crystalline bundles crack or the molecular chains of the β-form are separated from the lateral side after annealing after a certain annealing time. A model to describe the microstructural evolution of the ordered structure during annealing was established based on the results obtained.
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Affiliation(s)
- Jian Yang
- Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, Hunan University of Technology, Zhuzhou 412007, China
- National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou 412007, China
| | - Xianggui Liu
- Guangdong Huatong New Material Technology Co., Ltd., Dongguan 523591, China
| | - Jinxing Zhao
- Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, Hunan University of Technology, Zhuzhou 412007, China
- National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou 412007, China
| | - Xuelian Pu
- Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, Hunan University of Technology, Zhuzhou 412007, China
- National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou 412007, China
| | - Zetong Shen
- Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, Hunan University of Technology, Zhuzhou 412007, China
- National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou 412007, China
| | - Weiyi Xu
- Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, Hunan University of Technology, Zhuzhou 412007, China
- National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou 412007, China
| | - Yuejun Liu
- Key Laboratory of Advanced Packaging Materials and Technology of Hunan Province, Hunan University of Technology, Zhuzhou 412007, China
- National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Hunan University of Technology, Zhuzhou 412007, China
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Ju Y, Qiao Z, Xiu H, Liu X, Fu Q, Bai H. Combined effects of matrix molecular weight and crystallinity on the impact toughness of PP/EPR blends: The role of chain entanglement. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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Remarkably improved toughness of isotactic polypropylene realized by introducing star-shaped SEBS and annealing treatment. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04208-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Liu J, Jiang D, Li Z. Annealing‐induced high impact toughness of immiscible isotactic polypropylene/poly(acrylonitrile‐butadiene‐styrene) blend. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jingru Liu
- Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering Changzhou University Changzhou China
| | - Dexing Jiang
- Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering Changzhou University Changzhou China
| | - Zihan Li
- Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering Changzhou University Changzhou China
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Bi S, Zhao W, Sun Y, Jiang C, Liu Y, He Z, Li Q, Song J. Dynamic photonic perovskite light-emitting diodes with post-treatment-enhanced crystallization as writable and wipeable inscribers. NANOSCALE ADVANCES 2021; 3:6659-6668. [PMID: 36132659 PMCID: PMC9418838 DOI: 10.1039/d1na00465d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/14/2021] [Indexed: 05/30/2023]
Abstract
Controllable photonic patterns have attracted great attention for various applications in displays, smart sensors, and communications. Conventional patterned light-emitting-diode (LED) systems require complicated design, complex procedure, and advanced equipment. Moreover, permanent properties of the fabricated patterns on LED restrict it from various important applications. Herein, we present an innovative writable and wipeable perovskite light-emitting-diode (WWPeLED) device, which tactfully utilizes the large variation of turn-on voltage originating from the external quantum efficiency (EQE) difference under controllable thermal treatment. The turn-on voltages with/without thermal-treatment devices exhibit a large gap of over 5 V, and the thermal-treatment electroluminescence intensity is more than 10 times higher than that of non-thermal-treatment devices. The new phenomena open up an effective way of controlling illumination with desired pattern designs. Additionally, the distinct handwriting fonts and habits as well as printing patterns with illumination WWPeLED are also realized. Furthermore, these written and printed features can be totally wiped out with an 11 V cleaning voltage, turning the devices as a regular fully bright PeLED. The stability and repeatability tests prove the robustness of WWPeLED in both mechanical and electroluminescence performance after a long period of operations. The innovative WWPeLED devices may find prospective applications in various optoelectronic devices and flexible integrated systems.
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Affiliation(s)
- Sheng Bi
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, School of Mechanical Engineering, Dalian University of Technology Dalian 116024 China
| | - Wei Zhao
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, School of Mechanical Engineering, Dalian University of Technology Dalian 116024 China
| | - Yeqing Sun
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, School of Mechanical Engineering, Dalian University of Technology Dalian 116024 China
| | - Chengming Jiang
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, School of Mechanical Engineering, Dalian University of Technology Dalian 116024 China
| | - Yun Liu
- Department of Mechanical Engineering, University of Maryland College Park MA 20742 USA
| | - Zhengran He
- Center for Materials for Information Technology, The University of Alabama Tuscaloosa AL 35487 USA
| | - Qikun Li
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, School of Mechanical Engineering, Dalian University of Technology Dalian 116024 China
| | - Jinhui Song
- Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education, School of Mechanical Engineering, Dalian University of Technology Dalian 116024 China
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Improving Mechanical Properties for Extrusion-Based Additive Manufacturing of Poly(Lactic Acid) by Annealing and Blending with Poly(3-Hydroxybutyrate). Polymers (Basel) 2019; 11:polym11091529. [PMID: 31546970 PMCID: PMC6780387 DOI: 10.3390/polym11091529] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 02/05/2023] Open
Abstract
Based on differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, polarizing microscope (POM), and scanning electron microscopy (SEM) analysis, strategies to close the gap on applying conventional processing optimizations for the field of 3D printing and to specifically increase the mechanical performance of extrusion-based additive manufacturing of poly(lactic acid) (PLA) filaments by annealing and/or blending with poly(3-hydroxybutyrate) (PHB) were reported. For filament printing at 210 °C, the PLA crystallinity increased significantly upon annealing. Specifically, for 2 h of annealing at 100 °C, the fracture surface became sufficiently coarse such that the PLA notched impact strength increased significantly (15 kJ m−2). The Vicat softening temperature (VST) increased to 160 °C, starting from an annealing time of 0.5 h. Similar increases in VST were obtained by blending with PHB (20 wt.%) at a lower printing temperature of 190 °C due to crystallization control. For the blend, the strain at break increased due to the presence of a second phase, with annealing only relevant for enhancing the modulus.
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Li Y, Wurster DE. The Effects of Curing and Casting Methods on the Physicochemical Properties of Polymer Films. AAPS PharmSciTech 2018; 19:2740-2749. [PMID: 29978291 DOI: 10.1208/s12249-018-1113-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/20/2018] [Indexed: 11/30/2022] Open
Abstract
Most film coatings in the pharmaceutical industry are prepared using organic solvents or aqueous solvents. Due to different film-formation mechanisms, their properties are significantly different from each other. Curing can alter the microstructure of films by improving the coalescence of polymer particles for aqueous dispersion-based films or accelerating macromolecule relaxation for organic solvent-based films. The aim of this study was to investigate the effects of preparation methods and curing on the physicochemical properties of Kollicoat® SR30D and Kollicoat® MAE100P films. The film's properties, including water diffusion coefficient, mechanical properties, plasticizer loss, swelling behavior, and contact angle, were measured for uncured or cured aqueous dispersion-based or organic solvent-based films. The results indicated that curing decreased water diffusivities in films and increased film's tensile strength. Curing resulted in plasticizer loss from SR30D films but not from MAE100P films due to strong interaction between plasticizer and MAE100P. The surface of organic solvent-based films was more hydrophobic than that of aqueous dispersion-based films. The contact angle of organic solvent-based films was increased after curing possibly because curing decreased roughness of the film surface. Organic solvent-based SR30D films had better mechanical properties than the corresponding aqueous dispersion-based films because of higher degree of polymer-polymer entanglement in the organic solvent-based films. However, contradictory phenomena were observed in MAE100P films possibly due to a "core-shell" structure reserved in the aqueous dispersion-based MAE100P films. In summary, casting methods and curing have significant impact on the film properties due to different film structures, coalescence, or film relaxation, and other concurrent effects including evaporation of residue solvent and plasticizers.
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Li Y, He S, He H, Yu P, Wang D. Study on low temperature toughness and crystallization behavior of polypropylene random copolymer. JOURNAL OF POLYMER ENGINEERING 2017. [DOI: 10.1515/polyeng-2016-0169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
This research designed a series of novel approaches aiming to tackle a long-standing problem that is the brittleness of polypropylene (PP) random copolymer (PPR) at low temperature. By introducing polyolefin elastomer (POE), the toughness of PPR was improved; talc improved the stiffness of PPR, low density polyethylene (LDPE) or high density PE (HDPE) improved the low temperature toughness of PPR, and annealing treatment also improved the low temperature toughness of PPR significantly. The addition of dicumyl peroxide (DCP) and triallyl isocyanurate (TAIC) increased its stiffness through the formation of cross-linking networks. Also, the crystallization behavior and morphology were investigated in detail. Differential scanning calorimetry (DSC) results indicated that the adoption of annealing treatment can improve the crystallinity of PPR, while a polarizing microscope revealed that the incorporation of foreign matter can facilitate the crystallization process of the matrix. X-ray diffraction (XRD) tests showed an unchanged polymorphic composition of PPR after introducing different additives, and scanning electron microscopy (SEM) indicated that annealing treatment can enhance interfacial interactions between the matrix and fillers.
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Yang J, Zhu H, Zhao Y, Jiang Q, Chen H, Liu G, Chen P, Wang D. New insights into the beta-form crystal toughening mechanism in pre-oriented PHBV films. Eur Polym J 2017. [DOI: 10.1016/j.eurpolymj.2017.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Chai LG, Zhou HX, Sun XL, Li HH, Yan SK, Yang XQ. Structure of friction-transferred highly oriented poly(3-hexylthiophene) thin films. CHINESE JOURNAL OF POLYMER SCIENCE 2016. [DOI: 10.1007/s10118-016-1770-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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