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Rigoglioso VP, Boydston AJ. Flow Optimization of Photoredox-Mediated Metal-Free Ring-Opening Metathesis Polymerization. ACS Macro Lett 2023; 12:1479-1485. [PMID: 37870749 DOI: 10.1021/acsmacrolett.3c00545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
Photoredox-mediated metal-free ring-opening metathesis polymerization (MF-ROMP) is a convenient metal-free method to produce a variety of ROMP polymers. Transitioning MF-ROMP from a batch to a continuous flow process has yet to be demonstrated and could potentially benefit the production efficiency, safety, and modularity of reaction conditions. We designed and evaluated continuous flow and droplet flow setups and compared the results for MF-ROMP across a short series of common monomers. By using the droplet flow reactor setup, we achieved flow conversions comparable to that of batch and circumvented issues with diffusion-limited mixing and air exposure.
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Affiliation(s)
- Vincent P Rigoglioso
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Andrew J Boydston
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Chemical and Biological Engineering, Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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2
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Opaluwa C, Lott T, Karbstein HP, Emin MA. Encapsulation of oil in the high moisture extrusion of wheat gluten: Interrelation between process parameters, matrix viscosity and oil droplet size. FUTURE FOODS 2023. [DOI: 10.1016/j.fufo.2023.100222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023] Open
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3
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Perin D, Dorigato A, Pegoretti A. Thermoplastic
self‐healing
polymer blends for structural composites: Development of polyamide 6 and cyclic olefinic copolymer blends. J Appl Polym Sci 2023. [DOI: 10.1002/app.53751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- D. Perin
- Department of Industrial Engineering and INSTM Research Unit University of Trento Trento Italy
| | - A. Dorigato
- Department of Industrial Engineering and INSTM Research Unit University of Trento Trento Italy
| | - A. Pegoretti
- Department of Industrial Engineering and INSTM Research Unit University of Trento Trento Italy
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4
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Ferreira AC, Bomfim MRQ, da Costa Sobrinho CHDB, Boaz DTL, Da Silva Lira R, Fontes VC, Arruda MO, Zago PMW, Filho CAAD, Dias CJM, da Rocha Borges MO, Ribeiro RM, Bezerra CWB, Penha RS. Characterization, antimicrobial and cytotoxic activity of polymer blends based on chitosan and fish collagen. AMB Express 2022; 12:102. [PMID: 35925495 PMCID: PMC9352841 DOI: 10.1186/s13568-022-01433-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/05/2022] [Indexed: 11/10/2022] Open
Abstract
This study aims to produce, characterize, and assess the antimicrobial activity and cytotoxicity of polymer blends based on chitosan (CT) and fish collagen (COL) produced by different precipitation methods. Polymer blends were obtained in alkaline (NaOH), saline (NaCl), and alkaline/saline (NaOH/NaCl) solutions with different CT:COL concentration ratios (20:80, 50:50, and 80:20). The polymer blends were characterized by various physicochemical methods and subsequently evaluated in terms of their in vitro antimicrobial and cytotoxicity activity. In this study, the degree of chitosan deacetylation was 82%. The total hydroxyproline and collagen content in the fish matrix was 47.56 mg. g-1 and 394.75 mg. g-1, respectively. The highest yield was 44% and was obtained for a CT:COL (80:20) blend prepared by precipitation in NaOH. High concentrations of hydroxyproline and collagen in the blends were observed when NaOH precipitation was used. Microbiological analysis revealed that the strains used in this work were sensitive to the biomaterial; this sensitivity was dose-dependent and increased with increasing chitosan concentration in the products. The biocompatibility test showed that the blends did not reduce the viability of fibroblast cells after 48 h of culture. An analysis of the microbiological activity of the all-polymer blends showed a decrease in the values of minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) for S. aureus and P. aeruginosa. The blends showed biocompatibility with NIH-3T3 murine fibroblast cells and demonstrated their potential for use in biomedical applications such as wound healing, implants, and scaffolds.
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Affiliation(s)
- Andressa Coelho Ferreira
- Programa de Doutorado em Biotecnologia (RENORBIO), Universidade Federal do Maranhão (UFMA), São Luís, Brazil
| | - Maria Rosa Quaresma Bomfim
- Programa de Doutorado em Biotecnologia (RENORBIO), Universidade Federal do Maranhão (UFMA), São Luís, Brazil
| | | | | | | | | | | | | | | | | | | | | | | | - Rosiane Silva Penha
- Instituto Federal de Educação, Ciência e Tecnologia do Maranhão (IFMA), S/N, Residencial Val paraíso, Sapucaia, Rosario, 65143-000, Brazil.
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5
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Soltanolkottabi F. Application of Fourier’s law in thermally induced phase separation (TIPS) process for porous poly(L-lactide) films. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04359-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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6
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Wong WB, de Bie VG, Hulsen MA, Anderson PD. Numerical Modeling of the Blend Morphology Evolution in Twin‐Screw Extruders. MACROMOL THEOR SIMUL 2022. [DOI: 10.1002/mats.202100087] [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)
- Wing‐Hin B. Wong
- Polymer Technology Department of Mechanical Engineering Eindhoven University of Technology Eindhoven MB P.O. Box 513 5600 The Netherlands
| | - Vincent G. de Bie
- Polymer Technology Department of Mechanical Engineering Eindhoven University of Technology Eindhoven MB P.O. Box 513 5600 The Netherlands
| | - Martien A. Hulsen
- Polymer Technology Department of Mechanical Engineering Eindhoven University of Technology Eindhoven MB P.O. Box 513 5600 The Netherlands
| | - Patrick D. Anderson
- Polymer Technology Department of Mechanical Engineering Eindhoven University of Technology Eindhoven MB P.O. Box 513 5600 The Netherlands
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7
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Macromolecular Insights into the Altered Mechanical Deformation Mechanisms of Non-Polyolefin Contaminated Polyolefins. Polymers (Basel) 2022; 14:polym14020239. [PMID: 35054644 PMCID: PMC8779932 DOI: 10.3390/polym14020239] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 02/01/2023] Open
Abstract
Current recycling technologies rarely achieve 100% pure plastic fractions from a single polymer type. Often, sorted bales marked as containing a single polymer type in fact contain small amounts of other polymers as contaminants. Inevitably, this will affect the properties of the recycled plastic. This work focuses on understanding the changes in tensile deformation mechanism and the related mechanical properties of the four dominant types of polyolefin (PO) (linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP)), contaminated with three different non-polyolefin (NPO) polymers (polyamide-6 (PA-6), polyethylene terephthalate (PET), and polystyrene (PS)). Under the locally elevated stress state induced by the NPO phase, the weak interfacial adhesion typically provokes decohesion. The resulting microvoids, in turn, initiate shear yielding of the PO matrix. LLDPE, due to the linear structure and intercrystalline links, is well able to maintain high ductility when contaminated. LDPE shows deformation similar to the pure material, but with decreasing ductility as the amount of NPO increases. Addition of 20 wt% PA-6, PET, and PS causes a drop in strain at break of 79%, 63%, and 84%, respectively. The typical ductile necking of the high-crystalline HDPE and PP is strongly disturbed by the NPO phase, with a transition even to full brittle failure at high NPO concentration.
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8
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Fortelný I, Jůza J. The Effects of Copolymer Compatibilizers on the Phase Structure Evolution in Polymer Blends-A Review. MATERIALS 2021; 14:ma14247786. [PMID: 34947377 PMCID: PMC8707745 DOI: 10.3390/ma14247786] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/23/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022]
Abstract
This paper summarizes the results of studies describing the effect of block and graft copolymers on the phase structure formation and evolution in immiscible polymer blends. The main phenomenological rules for prediction of the copolymer compatibilization efficiency are briefly described and compared with selected experimental data. The results of the theories of equilibrium distribution of a copolymer between the blend interface and the bulk phases and its effect on the blend interfacial tension are summarized. The theories of the compatibilizer effect on the droplet breakup in flow are analyzed. The mechanisms of the copolymer effect on the coalescence of droplets in flow are compared and their effect on the droplet size is shown. The problems of reliable description of the effect of a copolymer on the coalescence in quiescent state are presented. Obstacles to derivation of a realistic theory of the copolymer effect on the competition between the droplet breakup and coalescence are discussed. Selected experimental data are compared with the theoretical results.
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9
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A Novel Multiscale Methodology for Simulating Droplet Morphology Evolution during Injection Molding of Polymer Blends. Polymers (Basel) 2020; 13:polym13010133. [PMID: 33396929 PMCID: PMC7795296 DOI: 10.3390/polym13010133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 11/16/2022] Open
Abstract
The morphology of polymer blends plays a critical role in determining the properties of the blends and performance of resulting injection-molded parts. However, it is currently impossible to predict the morphology evolution during injection molding and the final micro-structure of the molded parts, as the existing models for the morphology evolution of polymer blends are still limited to a few simple flow fields. To fill this gap, this paper proposed a novel model for droplet morphology evolution during the mold filling process of polymer blends by coupling the models on macro- and meso-scales. The proposed model was verified by the injection molding experiment of PP/POE blends. The predicted curve of mold cavity pressure during filling process agreed precisely with the data of the corresponding pressure sensors. On the other hand, the model successfully tracked the moving trajectory and simulated morphology evolution of the droplets during the mold-filling process. After mold-filling ended, the simulation results of the final morphology of the droplets were consistent with the observations of the scanning electron microscope (SEM) experiment. Moreover, this study revealed the underlying mechanism of the droplet morphology evolution through the force analysis on the droplet. It is validated that the present model is a qualified tool for simulating the morphology evolution of polymer blends during injection molding and predicting the final microstructure of the products.
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Kuzmanović M, Delva L, Cardon L, Ragaert K. Relationship between the Processing, Structure, and Properties of Microfibrillar Composites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2003938. [PMID: 33191562 DOI: 10.1002/adma.202003938] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/19/2020] [Indexed: 06/11/2023]
Abstract
The relationship between processing, morphology, and properties of polymeric materials has been the subject of numerous studies of academic and industrial research. Finding an answer to this question might result in guidelines on how to design polymeric materials. Microfibrillar composites (MFCs) are an interesting class of polymer-polymer composites. The advantage of the MFC concept lies in developing in situ microfibrils by which a perfect homogeneous distribution of the reinforcement in the matrix can be achieved. Their potentially excellent mechanical properties are strongly dependent on the aspect ratio of the fibrils, which is developed through a three-stage production process: melt blending, fibrillation, and isotropization. During melt blending, the polymers undergo different morphological changes, such as a breakup and coalescence of the droplets, which play a crucial role in defining the microstructure. During processing, various parameters may affect the morphology of the MFCs, which must be taken into account. Besides the processing parameters, the microstructure of the composite is dependent on the composition ratio of the blend and viscosity of the components, as well as the dispersion and distribution of the microfibrils. The objective here is to outline this importance and bring together an overview of the processing-structure-property relationship for MFCs.
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Affiliation(s)
- Maja Kuzmanović
- Centre for Polymer and Material Technologies, Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 130, Zwijnaarde, 9052, Belgium
| | - Laurens Delva
- Centre for Polymer and Material Technologies, Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 130, Zwijnaarde, 9052, Belgium
| | - Ludwig Cardon
- Centre for Polymer and Material Technologies, Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 130, Zwijnaarde, 9052, Belgium
| | - Kim Ragaert
- Centre for Polymer and Material Technologies, Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Technologiepark 130, Zwijnaarde, 9052, Belgium
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11
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Wang Y, Qian L, Chen Z, Zhou F. Coalescence of Binary Droplets in the Transformer Oil Based on Small Amounts of Polymer: Effects of Initial Droplet Diameter and Collision Parameter. Polymers (Basel) 2020; 12:polym12092054. [PMID: 32917051 PMCID: PMC7570392 DOI: 10.3390/polym12092054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/29/2020] [Accepted: 09/07/2020] [Indexed: 11/16/2022] Open
Abstract
In engineering applications, the coalescence of droplets in the oil phase dominates the efficiency of water-oil separation. To improve the efficiency of water-oil separation, many studies have been devoted to exploring the process of water droplets colliding in the oil phase. In this paper, the volume of fluid (VOF) method is employed to simulate the coalescence of water droplets in the transformer oil based on small amounts of polymer. The influences of the initial diameter and collision parameter of two equal droplets on droplet deformation and coalescence time are investigated. The time evolution curves of the dimensionless maximum deformation diameter of the droplets indicate that the larger the droplet diameter, the more obvious the deformation from central collisions. As the collision parameter increases, the contact area of the two droplets, as well as the kinetic energy that is converted into surface energy, decreases, resulting in an increase in droplet deformation. Furthermore, the effects of the initial droplet diameter and collision parameter on coalescence time are also investigated and discussed. The results reveal that as the initial droplet diameter and collision parameter increase, the droplet coalescence time increases.
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12
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Prieto JL. Viscoelastic Effects on Drop Deformation Using a Machine Learning-Enhanced, Finite Element method. Polymers (Basel) 2020; 12:polym12081652. [PMID: 32722371 PMCID: PMC7464509 DOI: 10.3390/polym12081652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 01/24/2023] Open
Abstract
This paper presents a numerical study of the viscoelastic effects on drop deformation under two configurations of interest: steady shear flow and complex flow under gravitational effects. We use a finite element method along with Brownian dynamics simulation techniques that avoid the use of closed-form, constitutive equations for the “micro-”scale, studying the viscoelastic effects on drop deformation using an interface capturing technique. The method can be enhanced with a variance-reduced approach to the stochastic modeling, along with machine learning techniques to reconstruct the shape of the polymer stress tensor in complex problems where deformations can be dramatic. The results highlight the effects of viscoelasticity on shape, the polymer stress tensor, and flow streamlines under the analyzed configurations.
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Affiliation(s)
- Juan Luis Prieto
- Escuela Técnica Superior de Ingenieros Industriales, Departamento de Ingeniería Energética, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006 Madrid, Spain
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13
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Compatibilization of Poly(Lactic Acid) (PLA) and Bio-Based Ethylene-Propylene-Diene-Rubber (EPDM) via Reactive Extrusion with Different Coagents. Polymers (Basel) 2020; 12:polym12030605. [PMID: 32155924 PMCID: PMC7182849 DOI: 10.3390/polym12030605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/18/2020] [Accepted: 02/22/2020] [Indexed: 11/16/2022] Open
Abstract
Much effort has been made to enhance the toughness of poly (lactic acid) (PLA) to broaden its possible range of usage in technical applications. In this work, the compatibility of PLA with a partly bio-based ethylene-propylene-diene-rubber (EPDM) through reactive extrusion was investigated. The concentration of EPDM in the PLA matrix was in the range of up to 20%. The reactive extrusion was carried out in a conventional twin-screw extruder. Contact angle measurements were performed to calculate the interfacial tension and thus the compatibility between the phases. The thermal and mechanical properties as well as the phase morphology of the blends were characterized. A copolymer of poly (ethylene-co-methyl acrylate-co-glycidyl methacrylate) (EMAGMA) was used as compatibilizer, which leads to a significant reduction in the particle size of the dispersed rubber phase when compared with the blends without this copolymer. The use of EMAGMA combined with soybean oil (SBO) and a radical initiator enhances the elongation at break of the compound. The results indicate that the reduction of the particle size of the dispersed phase obtained with the compatibilizer alone is not sufficient to improve the mechanical properties of the blend system. The induced radical reactions also influenced the mechanical properties of the blend significantly.
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Qian L, Cong H, Zhu C. A Numerical Investigation on the Collision Behavior of Polymer Droplets. Polymers (Basel) 2020; 12:polym12020263. [PMID: 31991675 PMCID: PMC7077334 DOI: 10.3390/polym12020263] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/02/2020] [Accepted: 01/02/2020] [Indexed: 01/31/2023] Open
Abstract
Binary droplet collisions are a key mechanism in powder coatings production, as well as in spray combustion, ink-jet printing, and other spray processes. The collision behavior of the droplets using Newtonian and polymer liquids is studied numerically by the coupled level-set and volume of fluid (CLSVOF) method and adaptive mesh refinement (AMR). The deformation process, the internal flow fields, and the energy evolution of the droplets are discussed in detail. For binary polymer droplet collisions, compared with the Newtonian liquid, the maximum deformation is promoted. Due to the increased viscous dissipation, the colliding droplets coalesce more slowly. The stagnant flow region in the velocity field increases and the flow re-direction phenomenon is suppressed, so the polymer droplets coalesce permanently. As the surface tension of the polymer droplets decreases, the kinetic and the dissipated energy increases. The maximum deformation is promoted, and the coalescence speed of the droplets slows down. During the collision process, the dominant pressure inside the polymer droplets varies from positive pressure to negative pressure and then to positive pressure. At low surface tension, due to the non-synchronization in the movement of the interface front, the pressure is not smooth and distributes asymmetrically near the center of the droplets.
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