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Lagarinhos J, Magalhães da Silva S, Oliveira JM. Non-Isothermal Crystallization Kinetics of Polyamide 6/Graphene Nanoplatelets Nanocomposites Obtained via In Situ Polymerization: Effect of Nanofiller Size. Polymers (Basel) 2023; 15:4109. [PMID: 37896362 PMCID: PMC10610371 DOI: 10.3390/polym15204109] [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: 08/31/2023] [Revised: 09/29/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Thermoplastic resin transfer molding (T-RTM) technology was applied to synthesize graphene nanoplatelets-based nanocomposites via anionic ring-opening polymerization (AROP). Polyamide 6 (PA6) was obtained by AROP and was used as the polymeric matrix of the developed nanocomposites. The non-isothermal crystallization behavior of PA6 and nanocomposites was analyzed by differential scanning calorimetry (DSC). Nanocomposites with 0.5 wt.% of graphene nanoplatelets (GNPs) with two different diameter sizes were prepared. Results have shown that the crystallization temperature shifted to higher values in the presence of GNPs. This behavior is more noticeable for the nanocomposite prepared with smaller GNPs (PA6/GN). The crystallization kinetic behavior of all samples was assessed by Avrami and Liu's models. It was observed that GNPs increased the crystallization rate, thus revealing a nucleating ability, and also validated the reduction of half-time crystallization values. Such tendency was also supported by the lower activation energy values determined by Friedman's method.
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Affiliation(s)
- Joana Lagarinhos
- EMaRT Group—Emerging: Materials, Research, Technology, University of Aveiro, 3810-193 Aveiro, Portugal; (J.L.); (J.M.O.)
- School of Design, Management and Production Technologies, University of Aveiro, Estrada do Cercal 449, 3720-509 Oliveira de Azeméis, Portugal
- CICECO—Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Sara Magalhães da Silva
- EMaRT Group—Emerging: Materials, Research, Technology, University of Aveiro, 3810-193 Aveiro, Portugal; (J.L.); (J.M.O.)
- School of Design, Management and Production Technologies, University of Aveiro, Estrada do Cercal 449, 3720-509 Oliveira de Azeméis, Portugal
- CICECO—Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - José Martinho Oliveira
- EMaRT Group—Emerging: Materials, Research, Technology, University of Aveiro, 3810-193 Aveiro, Portugal; (J.L.); (J.M.O.)
- School of Design, Management and Production Technologies, University of Aveiro, Estrada do Cercal 449, 3720-509 Oliveira de Azeméis, Portugal
- CICECO—Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
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Semperger OV, Suplicz A. The degradation during recycling of polyamide 6 produced by anionic ring-opening polymerization of ε-caprolactam. Sci Rep 2023; 13:17130. [PMID: 37816784 PMCID: PMC10564943 DOI: 10.1038/s41598-023-44314-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 10/06/2023] [Indexed: 10/12/2023] Open
Abstract
As the plastics industry continues to grow, the amount of plastic waste is also increasing. The European Union is controlling plastic waste through various regulations, focusing primarily on recyclability. A good alternative to traditional thermoset composites is thermoplastic polyamide 6 composites produced by Thermoplastic Resin Transfer Molding (T-RTM). Polyamide 6 has high strength and is produced by in-situ anionic ring-opening polymerization in T-RTM. Products made with this technology can replace traditional thermoset composites in many areas, which greatly increases recyclability. In this paper, the recyclability of the high molecular weight polyamide 6 matrix material of T-RTM composites is investigated. Products were mechanically recycled and then processed by injection molding. Thermal, mechanical and rheological properties of the samples were compared with the properties of the original product, as well as a general injection molding-grade PA6. Results show that the parts prepared with this innovative technology can be mechanically recycled and reprocessed by injection molding without a processing aid. After reprocessing, a significant reduction in properties is observed due to degradation, but the properties of the resulting product are in good agreement with those of a conventional commercially available injection molding grade PA6 material.
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Affiliation(s)
- Orsolya Viktória Semperger
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, 1111, Hungary
- Production Division, Bay Zoltán Nonprofit Ltd. for Applied Research, Kondorfa utca 1, Budapest, 1116, Hungary
| | - András Suplicz
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, 1111, Hungary.
- MTA-BME Lendület Lightweight Polymer Composites Research Group, Műegyetem rkp. 3, Budapest, 1111, Hungary.
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Martins FP, Santos L, Torcato R, Lima PS, Oliveira JM. Reproducibility Study of the Thermoplastic Resin Transfer Molding Process for Glass Fiber Reinforced Polyamide 6 Composites. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4652. [PMID: 37444966 DOI: 10.3390/ma16134652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/14/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023]
Abstract
Polyamide 6 (PA6) thermoplastic composites have higher recyclability potential when compared to conventional thermoset composites. A disruptive liquid molding manufacturing technology named Thermoplastic Resin Transfer Molding (T-RTM) can be used for processing composites due to the low viscosity of the monomers and additives. In this process, polymerization, crystallization and shrinkage occur almost at the same time. If these phenomena are not controlled, they can compromise the reproducibility and homogeneity of the parts. This work studied the influence of packing pressure, as a process variable, throughout the filling and polymerization stages. To assess the process reproducibility and parts' homogeneity, physical, thermal and mechanical properties were analyzed in different areas of neat PA6 and composite parts. This study showed that a two-stage packing pressure can be successfully used to increase parts' homogeneity and process reproducibility. The use of 3.5 bar packing pressure during the polymerization stage resulted in mechanical properties with lower standard deviations, indicating a higher degree of homogeneity of the manufactured parts and higher process reproducibility. These results will be used for establishing the actual state of the technology and will be a base for future process optimization.
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Affiliation(s)
- Filipe P Martins
- EMaRT Group-Emerging: Materials, Research, Technology, School of Design, Management and Production Technologies Northern Aveiro, University of Aveiro, Estrada do Cercal, 449 Santiago de Riba Ul, 3720-509 Oliveira de Azeméis, Portugal
- CICECO Aveiro-Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Laura Santos
- EMaRT Group-Emerging: Materials, Research, Technology, School of Design, Management and Production Technologies Northern Aveiro, University of Aveiro, Estrada do Cercal, 449 Santiago de Riba Ul, 3720-509 Oliveira de Azeméis, Portugal
- CICECO Aveiro-Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Ricardo Torcato
- EMaRT Group-Emerging: Materials, Research, Technology, School of Design, Management and Production Technologies Northern Aveiro, University of Aveiro, Estrada do Cercal, 449 Santiago de Riba Ul, 3720-509 Oliveira de Azeméis, Portugal
- CICECO Aveiro-Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Paulo S Lima
- EMaRT Group-Emerging: Materials, Research, Technology, School of Design, Management and Production Technologies Northern Aveiro, University of Aveiro, Estrada do Cercal, 449 Santiago de Riba Ul, 3720-509 Oliveira de Azeméis, Portugal
- TEMA-Center for Mechanical Technology and Automation, Mechanical Engineering Department, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - José M Oliveira
- EMaRT Group-Emerging: Materials, Research, Technology, School of Design, Management and Production Technologies Northern Aveiro, University of Aveiro, Estrada do Cercal, 449 Santiago de Riba Ul, 3720-509 Oliveira de Azeméis, Portugal
- CICECO Aveiro-Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
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Semperger OV, Osváth Z, Pásztor S, Suplicz A. The effect of the titanium dioxide nanoparticles on the morphology and degradation of polyamide 6 prepared by anionic ring‐opening polymerization. POLYM ENG SCI 2022. [DOI: 10.1002/pen.25990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Orsolya Viktória Semperger
- Department of Polymer Engineering, Faculty of Mechanical Engineering Budapest University of Technology and Economics Budapest Hungary
| | - Zsófia Osváth
- Polymer Chemistry Research Group, Institute of Materials and Environmental Chemistry Research Centre for Natural Sciences Budapest Hungary
| | - Szabolcs Pásztor
- Polymer Chemistry Research Group, Institute of Materials and Environmental Chemistry Research Centre for Natural Sciences Budapest Hungary
| | - András Suplicz
- Department of Polymer Engineering, Faculty of Mechanical Engineering Budapest University of Technology and Economics Budapest Hungary
- MTA‐BME Lendület Lightweight Polymer Composites Research Group Budapest Hungary
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Innovative Injection Molding Process for the Fabrication of Woven Fabric Reinforced Thermoplastic Composites. Polymers (Basel) 2022; 14:polym14081577. [PMID: 35458327 PMCID: PMC9031425 DOI: 10.3390/polym14081577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/08/2022] [Accepted: 04/09/2022] [Indexed: 02/01/2023] Open
Abstract
Woven fabric reinforced thermoplastic composites have been gaining significant attention as a lightweight alternative to metal in various industrial fields owing to their high stiffness and strength. Conventional manufacturing processes of woven fabric reinforced thermoplastic composites can be divided into two steps: first, the manufacturing of intermediate material, known as prepreg; then, the formation of the final products from the prepregs. This two-step process increases the manufacturing cost and time of the final composite products. This study demonstrated that woven fabric reinforced thermoplastic composites could be fabricated by an innovative injection molding process instead of the two-step process. A structure placing an extra mesh, which is a new and key component, on the mold-side of woven fabric was devised so that the thermoplastic matrix could be impregnated up to the surface of the woven fabric during injection molding. Tensile tests were performed in the direction parallel to the yarns of the fabric on the injection-molded composites to confirm their mechanical properties. As a result, it was possible to fabricate woven fabric reinforced thermoplastic composites with increased mechanical properties using injection molding without prepreg, and the composites could be molded with a much shorter cycle time than the conventional process, such as thermoforming or over-molding process.
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Out-Of-Plane Permeability Evaluation of Carbon Fiber Preforms by Ultrasonic Wave Propagation. MATERIALS 2020; 13:ma13122684. [PMID: 32545522 PMCID: PMC7345138 DOI: 10.3390/ma13122684] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 01/27/2023]
Abstract
Out-of-plane permeability of reinforcement preforms is of crucial importance in the infusion of large and thick composite panels, but so far, there are no standard experimental methods for its determination. In this work, an experimental set-up for the measurement of unsaturated through thickness permeability based on the ultrasonic wave propagation in pulse echo mode is presented. A single ultrasonic transducer, working both as emitter and receiver of ultrasonic waves, was used to monitor the through thickness flow front during a vacuum assisted resin infusion experiment. The set-up was tested on three thick carbon fiber preforms, obtained by stacking thermal bonding of balanced or unidirectional plies either by automated fiber placement either by hand lay-up of unidirectional plies. The ultrasonic data were used to calculate unsaturated out-of-plane permeability using Darcy’s law. The permeability results were compared with saturated out-of-plane permeability, determined by a traditional gravimetric method, and validated by some analytical models. The results demonstrated the feasibility and potential of the proposed set-up for permeability measurements thanks to its noninvasive character and the one-side access.
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