Pub Date : 2024-10-05DOI: 10.1016/j.polymdegradstab.2024.111026
Patricia Cabrera-García , María D. Marrero , Antonio N. Benítez
The accumulation of plastics in the environment is a well-recognized issue. To address this, biodegradable materials such polylactic acid (PLA) have been developed. In natural environments such as soil or water, PLA degradation progresses slowly but steadily. To accelerate the degradation of the material, this study investigates the degradation of a biocomposite material using PLA as a matrix and Pennisetum setaceum fiber as reinforcement. Disintegration and marine biodegradability tests, both at the seawater/sediment interface and in marine sediment, were conducted. Different measurement tests were employed to quantify the degradation of PLA and composite samples, focusing on the mass loss and the variation of the mechanical and thermal properties. The results consistently demonstrated greater mass loss and mechanical property deterioration during the disintegration test compared to the marine biodegradability tests. Notably, the composite material exhibits more significant degradation than the pure polymer without fiber. For composite, the addition of fiber increased the degree of biodegradability compared to the plastic matrix.
{"title":"Disintegration and marine biodegradability of biocomposite using Pennisetum setaceum fiber and PLA as matrix","authors":"Patricia Cabrera-García , María D. Marrero , Antonio N. Benítez","doi":"10.1016/j.polymdegradstab.2024.111026","DOIUrl":"10.1016/j.polymdegradstab.2024.111026","url":null,"abstract":"<div><div>The accumulation of plastics in the environment is a well-recognized issue. To address this, biodegradable materials such polylactic acid (PLA) have been developed. In natural environments such as soil or water, PLA degradation progresses slowly but steadily. To accelerate the degradation of the material, this study investigates the degradation of a biocomposite material using PLA as a matrix and <em>Pennisetum setaceum</em> fiber as reinforcement. Disintegration and marine biodegradability tests, both at the seawater/sediment interface and in marine sediment, were conducted. Different measurement tests were employed to quantify the degradation of PLA and composite samples, focusing on the mass loss and the variation of the mechanical and thermal properties. The results consistently demonstrated greater mass loss and mechanical property deterioration during the disintegration test compared to the marine biodegradability tests. Notably, the composite material exhibits more significant degradation than the pure polymer without fiber. For composite, the addition of fiber increased the degree of biodegradability compared to the plastic matrix.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111026"},"PeriodicalIF":6.3,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.polymdegradstab.2024.111022
Kwang-Hyun Ryu , Ji-Hyun Cho , Hoon Kim , Hyeon-Su Jo , Jong-Ho Back , Hyun-Joong Kim
Recent research has increased in eco-friendly hot-melt adhesives as alternatives to conventional commercial hot-melt adhesives. However, there have been limitations in terms of removability and biodegradability. This study addresses these issues by designing a novel molecular structure for a single polymer, resulting in a sustainable hot-melt adhesive that offers strong adhesion, clear removability, and high biodegradability without additional additives. By varying the ratio of alcohol monomers 1,4-butanediol (BD) and ethylene glycol (EG) during polymerization, we synthesized poly(butylene adipate-co-butylene terephthalate-co-ethylene adipate-co-ethylene terephthalate) (PBEAT) with four block segments. We increased the open time by reducing the regularity of the molecular structure, controlling crystallization behavior, and inhibiting polymer chain packing. This improvement in wettability with the adherend allowed us to achieve a lap shear adhesion strength of 3.18 MPa. Additionally, we proposed a debonding mechanism based on the correlation between the crystallization temperature (Tc) block copolymer's and shear adhesion failure temperature (SAFT), demonstrating the removability of the prepared hot-melt adhesive. Finally, analyses of hydrolysis, enzymatic degradation, and biodegradation in compost confirmed that reduced crystallinity enhances biodegradability. PBE30AT, exhibiting the strongest adhesion strength, achieves complete degradation in compost within 20 days, faster than neat poly(butylene adipate-co-terephthalate) (PBAT). This research offers a novel and practical approach to enhancing the potential and expandability of sustainable adhesives by tailoring the molecular structure of the polymer.
{"title":"Designing the regularity of biodegradable copolyester for sustainable hot-melt adhesives: Adhesion, removability, and biodegradability","authors":"Kwang-Hyun Ryu , Ji-Hyun Cho , Hoon Kim , Hyeon-Su Jo , Jong-Ho Back , Hyun-Joong Kim","doi":"10.1016/j.polymdegradstab.2024.111022","DOIUrl":"10.1016/j.polymdegradstab.2024.111022","url":null,"abstract":"<div><div>Recent research has increased in eco-friendly hot-melt adhesives as alternatives to conventional commercial hot-melt adhesives. However, there have been limitations in terms of removability and biodegradability. This study addresses these issues by designing a novel molecular structure for a single polymer, resulting in a sustainable hot-melt adhesive that offers strong adhesion, clear removability, and high biodegradability without additional additives. By varying the ratio of alcohol monomers 1,4-butanediol (BD) and ethylene glycol (EG) during polymerization, we synthesized poly(butylene adipate-co-butylene terephthalate-co-ethylene adipate-co-ethylene terephthalate) (PBEAT) with four block segments. We increased the open time by reducing the regularity of the molecular structure, controlling crystallization behavior, and inhibiting polymer chain packing. This improvement in wettability with the adherend allowed us to achieve a lap shear adhesion strength of 3.18 MPa. Additionally, we proposed a debonding mechanism based on the correlation between the crystallization temperature (T<sub>c</sub>) block copolymer's and shear adhesion failure temperature (SAFT), demonstrating the removability of the prepared hot-melt adhesive. Finally, analyses of hydrolysis, enzymatic degradation, and biodegradation in compost confirmed that reduced crystallinity enhances biodegradability. PBE<sub>30</sub>AT, exhibiting the strongest adhesion strength, achieves complete degradation in compost within 20 days, faster than neat poly(butylene adipate-co-terephthalate) (PBAT). This research offers a novel and practical approach to enhancing the potential and expandability of sustainable adhesives by tailoring the molecular structure of the polymer.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111022"},"PeriodicalIF":6.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.polymdegradstab.2024.111021
Haochen Yuan , Sherif Araby , Kangbo Zhao , Mohammed Salah , Yin Yu , Tianqing Liu , Qingshi Meng
In response to the global focus on environmental preservation and sustainable practices, developing nanocomposites featuring recyclable and healing properties is indispensable for high-performance and long-life structures. This study presents a facile approach to develop a recyclable and thermally-induced healing polyurea (PU)/graphene platelet (GNP) nanocomposites with high mechanical properties. A straightforward synthesis method was employed using isophorone diamine (IPDA) as chain extender with rigid cyclic structure. GNPs were modified with IPDA before adding into PU, showing remarkable enhancements in mechanical performance. At 0.10 wt.% GNPs, PU nanocomposites exhibited the maximum mechanical properties, with modified GNPs (M-GNPs) significantly outperforming pristine GNPs. Specifically, the tensile strength of PU increased by 41.3 % with M-GNPs, compared to only 12 % with pristine GNPs, underscoring the critical role of modifying the reinforcing phase. Furthermore, the nanocomposites demonstrated outstanding healing capabilities, achieving 89 % healing efficiency after 24 h at 120 °C. In addition, PU/M-GNP nanocomposites showed exceptional resistance to acidic and alkaline environments in comparison to neat PU. The study not only exemplifies developing high-strength and environmentally friendly materials but also holds promise for diverse applications, including aerospace, vibration damping, and protective coatings.
{"title":"Enhancing the performance of recyclable polyurea through coordination of rigid chain segments and graphene platelets","authors":"Haochen Yuan , Sherif Araby , Kangbo Zhao , Mohammed Salah , Yin Yu , Tianqing Liu , Qingshi Meng","doi":"10.1016/j.polymdegradstab.2024.111021","DOIUrl":"10.1016/j.polymdegradstab.2024.111021","url":null,"abstract":"<div><div>In response to the global focus on environmental preservation and sustainable practices, developing nanocomposites featuring recyclable and healing properties is indispensable for high-performance and long-life structures. This study presents a facile approach to develop a recyclable and thermally-induced healing polyurea (PU)/graphene platelet (GNP) nanocomposites with high mechanical properties. A straightforward synthesis method was employed using isophorone diamine (IPDA) as chain extender with rigid cyclic structure. GNPs were modified with IPDA before adding into PU, showing remarkable enhancements in mechanical performance. At 0.10 wt.% GNPs, PU nanocomposites exhibited the maximum mechanical properties, with modified GNPs (<em>M-</em>GNPs) significantly outperforming pristine GNPs. Specifically, the tensile strength of PU increased by 41.3 % with <em>M-</em>GNPs, compared to only 12 % with pristine GNPs, underscoring the critical role of modifying the reinforcing phase. Furthermore, the nanocomposites demonstrated outstanding healing capabilities, achieving 89 % healing efficiency after 24 h at 120 °C. In addition, PU/<em>M-</em>GNP nanocomposites showed exceptional resistance to acidic and alkaline environments in comparison to neat PU. The study not only exemplifies developing high-strength and environmentally friendly materials but also holds promise for diverse applications, including aerospace, vibration damping, and protective coatings.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111021"},"PeriodicalIF":6.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.polymdegradstab.2024.111024
Rafael Juan , M. Teresa Expósito , Beatriz Paredes , Daniel Lechuga , Cristina Martínez , Andres Cardil , Lola Aguilera-Villegas , Javier Ramos , Carlos Domínguez , Juan F. Vega , Rafael van Grieken , Rafael A. García-Muñoz
While the automotive industry has traditionally prioritized metal recycling, the increasing use of plastics in vehicles underlines the need for sustainable management of these materials. Recycling rates of plastics from end-of-life vehicles (ELVs) in Europe are low, but recent EU legislation requires 25 % of the plastics in new vehicles to be recycled, forcing innovative designs and strategies to enhance the recovery and quality of recycled resins. This study focuses on post-consumer bumpers, a significant recoverable component of ELVs, by assessing their molecular, morphological, rheological, and mechanical properties to investigate their homogeneity and quality from various sources to assess their suitability for recycling. Since the aging of these materials, caused by thermo-oxidative and thermo-mechanical degradation processes, can compromise the quality of recycled bumpers, we propose a blend of recycled PP from different bumper cars with virgin resin, representing a realistic scenario where the post-consumer ELV bumpers are collected. Interestingly, this blend, which can replace up to 50 % of the virgin resin without additional compatibilizers or additives, mitigates the degradation effects. Furthermore, the study evaluates the degradation resistance of these blends through multiple extrusion cycles and accelerated weathering tests in a temperature-controlled UV chamber to ascertain the number of cycles the material can tolerate without significant quality degradation, and to determine its suitability for long-term applications. Our results not only support the feasibility of using recycled PP for automotive components but also contribute to meeting the EU's recycling targets. This research highlights the potential for significant advances in the circularity of automotive plastics, providing a sustainable pathway for integrating recycled materials into new vehicle production.
虽然汽车行业传统上将金属回收作为优先事项，但汽车中塑料使用量的不断增加凸显了对这些材料进行可持续管理的必要性。欧洲报废汽车（ELV）中塑料的回收率很低，但最近欧盟立法要求对新车中 25% 的塑料进行回收，这迫使我们采用创新设计和策略来提高回收树脂的回收率和质量。消费后保险杠是 ELV 中的重要可回收成分，本研究将重点放在消费后保险杠上，通过评估其分子、形态、流变学和机械性能，研究其不同来源的均匀性和质量，以评估其是否适合回收利用。由于热氧化和热机械降解过程会导致这些材料的老化，从而影响回收保险杠的质量，因此我们建议将来自不同保险杠车的回收聚丙烯与原生树脂混合，这代表了收集消费后 ELV 保险杠的现实情况。有趣的是，这种混合物无需额外的相容剂或添加剂即可替代高达 50% 的原生树脂，从而减轻了降解效应。此外，这项研究还通过多次挤压循环和温控紫外线室加速老化试验对这些混合物的抗降解性进行了评估，以确定材料在无明显质量退化的情况下可承受的循环次数，并确定其是否适合长期应用。我们的研究结果不仅证明了在汽车部件中使用回收聚丙烯的可行性，还有助于实现欧盟的回收目标。这项研究凸显了在汽车塑料循环性方面取得重大进展的潜力，为将回收材料整合到新车生产中提供了一条可持续发展的途径。
{"title":"Enhancing the recyclability of ELV plastic bumpers: Characterization of molecular, morphological, rheological, mechanical properties and ageing degradation","authors":"Rafael Juan , M. Teresa Expósito , Beatriz Paredes , Daniel Lechuga , Cristina Martínez , Andres Cardil , Lola Aguilera-Villegas , Javier Ramos , Carlos Domínguez , Juan F. Vega , Rafael van Grieken , Rafael A. García-Muñoz","doi":"10.1016/j.polymdegradstab.2024.111024","DOIUrl":"10.1016/j.polymdegradstab.2024.111024","url":null,"abstract":"<div><div>While the automotive industry has traditionally prioritized metal recycling, the increasing use of plastics in vehicles underlines the need for sustainable management of these materials. Recycling rates of plastics from end-of-life vehicles (ELVs) in Europe are low, but recent EU legislation requires 25 % of the plastics in new vehicles to be recycled, forcing innovative designs and strategies to enhance the recovery and quality of recycled resins. This study focuses on post-consumer bumpers, a significant recoverable component of ELVs, by assessing their molecular, morphological, rheological, and mechanical properties to investigate their homogeneity and quality from various sources to assess their suitability for recycling. Since the aging of these materials, caused by thermo-oxidative and thermo-mechanical degradation processes, can compromise the quality of recycled bumpers, we propose a blend of recycled PP from different bumper cars with virgin resin, representing a realistic scenario where the post-consumer ELV bumpers are collected. Interestingly, this blend, which can replace up to 50 % of the virgin resin without additional compatibilizers or additives, mitigates the degradation effects. Furthermore, the study evaluates the degradation resistance of these blends through multiple extrusion cycles and accelerated weathering tests in a temperature-controlled UV chamber to ascertain the number of cycles the material can tolerate without significant quality degradation, and to determine its suitability for long-term applications. Our results not only support the feasibility of using recycled PP for automotive components but also contribute to meeting the EU's recycling targets. This research highlights the potential for significant advances in the circularity of automotive plastics, providing a sustainable pathway for integrating recycled materials into new vehicle production.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111024"},"PeriodicalIF":6.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.polymdegradstab.2024.111023
Yue Yao , Hanqi Qian , Dan Qi , Jinrui Bai , Chao Liu
As widely used lightweight and high-strength materials, the sustainable development of thermosetting composites is hampered by their limited recyclability. Developing simple methods for the efficient and upgraded recycling is desirable but challenging. Herein, carbon fiber reinforced degradable thermosetting resin composites were prepared, and the effects of resin degradation process and its derivatives on the sustainable recycling of carbon fiber were studied. Through the tunable departure and re-adsorption of degradation derivatives in cleaning post-treatment, recycled carbon fibers achieved not only non-destructive recovery but also simultaneously improvements in tensile strength from 3.0 GPa to 3.7 GPa and surface energy from 47.2 mN/m to 66.7 mN/m. The adhered derivatives, rich in -NH- and oxygen-containing groups, exhibited good interactions with the fiber surface and epoxy resin. Benefiting from this, the inter laminar shear strength of recycled carbon fibers reinforced epoxy composite effectively improved 24.3 %. In this work, directly reusing resin degradation products for the recycling of reinforced fibers was proposed and the key role of the composition and distribution of degradation products in recycling properties was revealed. The strategy of integrating characteristics of components to enhance material recyclability is expected to have widespread applicability, promoting the sustainable transition for thermosetting composites.
{"title":"Novel insights into the correlation composition-structure-property of recyclable carbon fiber reinforced thermosetting resin composites","authors":"Yue Yao , Hanqi Qian , Dan Qi , Jinrui Bai , Chao Liu","doi":"10.1016/j.polymdegradstab.2024.111023","DOIUrl":"10.1016/j.polymdegradstab.2024.111023","url":null,"abstract":"<div><div>As widely used lightweight and high-strength materials, the sustainable development of thermosetting composites is hampered by their limited recyclability. Developing simple methods for the efficient and upgraded recycling is desirable but challenging. Herein, carbon fiber reinforced degradable thermosetting resin composites were prepared, and the effects of resin degradation process and its derivatives on the sustainable recycling of carbon fiber were studied. Through the tunable departure and re-adsorption of degradation derivatives in cleaning post-treatment, recycled carbon fibers achieved not only non-destructive recovery but also simultaneously improvements in tensile strength from 3.0 GPa to 3.7 GPa and surface energy from 47.2 mN/m to 66.7 mN/m. The adhered derivatives, rich in -NH- and oxygen-containing groups, exhibited good interactions with the fiber surface and epoxy resin. Benefiting from this, the inter laminar shear strength of recycled carbon fibers reinforced epoxy composite effectively improved 24.3 %. In this work, directly reusing resin degradation products for the recycling of reinforced fibers was proposed and the key role of the composition and distribution of degradation products in recycling properties was revealed. The strategy of integrating characteristics of components to enhance material recyclability is expected to have widespread applicability, promoting the sustainable transition for thermosetting composites.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111023"},"PeriodicalIF":6.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25DOI: 10.1016/j.polymdegradstab.2024.111019
Hui Liu, Wenqiang Wang, Long Yan, Zhisheng Xu
The durability of fire-resistant performance is a great challenge for long-life wire and cable sheath materials. The commonly used flame-retardant cable sheath materials were aged by thermal, salt spray and hygrothermal accelerated methods. The effects of different environmental factors on the fire protection performance of cable sheath materials were investigated by cone calorimeter, limiting oxygen index, UL94, plastic smoke density, scanning electron microscope and Fourier transform infrared spectroscopy tests, and the ageing mechanism of cable sheath materials was proposed. The results show that the three accelerated ageing methods have a weakening effect on the fire resistance and charring properties of cable sheath materials. Among them, hygrothermal ageing treatment has the most serious impact on the fire-resistant performance compared with the unaged cable sheath material, including a decrease by 16.0 % in limiting oxygen index grade, an increase by 13.8 % in total heat release, a decrease by 75.8 % in light transmittance, and a decrease by 47.4 % in char residue at 800 °C. The deterioration of fire protection performance for cable sheath materials depends on the complex environmental conditions. The weakening effect of hygrothermal ageing is the strongest, followed by salt spray ageing, and the thermal ageing is the smallest. This work can provide strategic guidance for an in-depth analysis of the fire risk of ageing cables in complex environments.
{"title":"Flammability degradation behavior and ageing mechanism of flame-retardant cable sheath under different ageing conditions","authors":"Hui Liu, Wenqiang Wang, Long Yan, Zhisheng Xu","doi":"10.1016/j.polymdegradstab.2024.111019","DOIUrl":"10.1016/j.polymdegradstab.2024.111019","url":null,"abstract":"<div><div>The durability of fire-resistant performance is a great challenge for long-life wire and cable sheath materials. The commonly used flame-retardant cable sheath materials were aged by thermal, salt spray and hygrothermal accelerated methods. The effects of different environmental factors on the fire protection performance of cable sheath materials were investigated by cone calorimeter, limiting oxygen index, UL94, plastic smoke density, scanning electron microscope and Fourier transform infrared spectroscopy tests, and the ageing mechanism of cable sheath materials was proposed. The results show that the three accelerated ageing methods have a weakening effect on the fire resistance and charring properties of cable sheath materials. Among them, hygrothermal ageing treatment has the most serious impact on the fire-resistant performance compared with the unaged cable sheath material, including a decrease by 16.0 % in limiting oxygen index grade, an increase by 13.8 % in total heat release, a decrease by 75.8 % in light transmittance, and a decrease by 47.4 % in char residue at 800 °C. The deterioration of fire protection performance for cable sheath materials depends on the complex environmental conditions. The weakening effect of hygrothermal ageing is the strongest, followed by salt spray ageing, and the thermal ageing is the smallest. This work can provide strategic guidance for an in-depth analysis of the fire risk of ageing cables in complex environments.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111019"},"PeriodicalIF":6.3,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.polymdegradstab.2024.111020
Pierre Delliere, Luc Vincent, Nicolas Sbirrazzuoli, Nathanael Guigo
This article emphasizes the phenomena occurring in furan resins at high temperature, once they are polymerized and before their carbonization. The effects of the atmosphere (N2 and air) during the curing of furan resins were investigated and it is shown that upon exposure to air at temperatures above 175 °C, the furan resins develop an aromatic surface. By means of solid-state NMR and infrared spectroscopy, it is demonstrated that the aromatic groups are mainly located on the material's surface. A mechanism of this surface modification is proposed together with a short kinetic study. In addition, the thermo-mechanical properties are studied. The aromatic surfaces decrease the damping capacity of the material, yet its resistance to degradation is increased. Finally, tensile properties of the furan resins are not affected by the presence of this aromatic surface.
本文强调了呋喃树脂在高温下聚合后碳化前的现象。研究了呋喃树脂固化过程中大气（N2 和空气）的影响，结果表明，当暴露在温度高于 175 °C 的空气中时，呋喃树脂会形成芳香表面。固态核磁共振和红外光谱显示，芳香基团主要位于材料表面。研究人员提出了这种表面改性的机理，并进行了简短的动力学研究。此外，还对热机械性能进行了研究。芳香族表面降低了材料的阻尼能力，但却提高了材料的抗降解能力。最后，呋喃树脂的拉伸性能并没有因为芳香表面的存在而受到影响。
{"title":"Oxygen-induced surface hardening and aromatization of thermoset furanic biobased resin: Origin and consequences","authors":"Pierre Delliere, Luc Vincent, Nicolas Sbirrazzuoli, Nathanael Guigo","doi":"10.1016/j.polymdegradstab.2024.111020","DOIUrl":"10.1016/j.polymdegradstab.2024.111020","url":null,"abstract":"<div><div>This article emphasizes the phenomena occurring in furan resins at high temperature, once they are polymerized and before their carbonization. The effects of the atmosphere (N<sub>2</sub> and air) during the curing of furan resins were investigated and it is shown that upon exposure to air at temperatures above 175 °C, the furan resins develop an aromatic surface. By means of solid-state NMR and infrared spectroscopy, it is demonstrated that the aromatic groups are mainly located on the material's surface. A mechanism of this surface modification is proposed together with a short kinetic study. In addition, the thermo-mechanical properties are studied. The aromatic surfaces decrease the damping capacity of the material, yet its resistance to degradation is increased. Finally, tensile properties of the furan resins are not affected by the presence of this aromatic surface.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111020"},"PeriodicalIF":6.3,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing simple processes and significant effect modification method for polyester (PET) fabrics to resist hygrothermal aging is a formidable challenge. In this study, inspired by the silver mirror phenomenon of natural ginkgo nut, we utilized the pea pod-shaped nanoparticles that zinc oxide (ZnO) was encapsulated in polyhedral oligomeric silsesquioxane (ZnO@POSS), and polydimethylsiloxane (PDMS) to construct stabilized arc-shaped air layer on the PET fabric surface to resist high humidity environment. The round belly structures of pea pod-shaped ZnO@POSS and interlaced physical networks assisted by PDMS on the PET fabrics surface served as the crucial roles to capture and retain air, resulting in the capacity of the arc-shaped air layer was significantly larger than other microstructures underwater. The water vapor was prevented from entering the fabric interstices that the self-catalytic hydrolysis behavior of PET macromolecular chains was efficiently restrained, and the strength retention of PET fabric was significantly improved from 45 % to 89 % after accelerated hygrothermal aging test (60 °C, 80 % RH, 600 h). This work represents a simple and effective approach to improve the durability for PET fabrics in high humidity environments.
开发工艺简单、效果显著的聚酯（PET）织物抗湿热老化改性方法是一项艰巨的挑战。本研究受天然银杏果银镜现象的启发，利用多面体低聚硅倍半氧烷（ZnO@POSS）包裹氧化锌（ZnO）的豌豆荚状纳米粒子和聚二甲基硅氧烷（PDMS），在 PET 织物表面构建稳定的弧形空气层，以抵御高湿环境。PET 织物表面豌豆荚状 ZnO@POSS 的圆腹结构和 PDMS 辅助的交错物理网络起到了捕获和保留空气的关键作用，使得弧形空气层的容量明显大于水下的其他微结构。水蒸气被阻止进入织物间隙，从而有效抑制了 PET 高分子链的自催化水解行为，在加速湿热老化试验（60 °C, 80 % RH, 600 h）后，PET 织物的强度保持率从 45 % 显著提高到 89 %。这项工作是提高 PET 织物在高湿度环境中耐用性的一种简单而有效的方法。
{"title":"Arc-shaped air layer bioinspired by ginkgo nut to resist high humidity environment for PET fabrics","authors":"Yunshan Mao, Yinuo Shan, Zixing Xue, Lingfei Xu, Yu Guan, Shaohai Fu","doi":"10.1016/j.polymdegradstab.2024.111018","DOIUrl":"10.1016/j.polymdegradstab.2024.111018","url":null,"abstract":"<div><div>Developing simple processes and significant effect modification method for polyester (PET) fabrics to resist hygrothermal aging is a formidable challenge. In this study, inspired by the silver mirror phenomenon of natural ginkgo nut, we utilized the pea pod-shaped nanoparticles that zinc oxide (ZnO) was encapsulated in polyhedral oligomeric silsesquioxane (ZnO@POSS), and polydimethylsiloxane (PDMS) to construct stabilized arc-shaped air layer on the PET fabric surface to resist high humidity environment. The round belly structures of pea pod-shaped ZnO@POSS and interlaced physical networks assisted by PDMS on the PET fabrics surface served as the crucial roles to capture and retain air, resulting in the capacity of the arc-shaped air layer was significantly larger than other microstructures underwater. The water vapor was prevented from entering the fabric interstices that the self-catalytic hydrolysis behavior of PET macromolecular chains was efficiently restrained, and the strength retention of PET fabric was significantly improved from 45 % to 89 % after accelerated hygrothermal aging test (60 °C, 80 % RH, 600 h). This work represents a simple and effective approach to improve the durability for PET fabrics in high humidity environments.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111018"},"PeriodicalIF":6.3,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-22DOI: 10.1016/j.polymdegradstab.2024.111017
Zsófia Kovács , Andrea Toldy
The increasing importance of thermoplastic composites, driven by their enhanced recyclability and production efficiency, has attracted interest in continuous fibre-reinforced thermoplastic. Polyamide 6 (PA6), synthesised via anionic ring-opening polymerisation, is particularly relevant, however, the flammability of PA6 poses significant challenges and a critical concern for their structural application, necessitating effective flame retardancy measures. This study investigates the development of flame retardant coatings for carbon fibre-reinforced PA6 composites, employing hexaphenoxycyclotriphosphazene (HPCTP) and expandable graphite (EG), and evaluates their efficacy in improving the flammability properties of the composites through their combined modes of action. We investigated the impact of FRs on glass transition temperature, crystallinity, thermal stability, monomer conversion and flammability properties. The best-performing formulations (PA6/3P%HPCTP/3%EG and PA6/3P%HPCTP/4%EG) were applied to the surface of carbon fibre-reinforced PA6 composites by in-mould coating. Due to the synergistic effect of HPCTP and EG, the coatings containing 3P% HPCTP and 3 % EG reduced the maximum heat release by 33 % and the total heat release by 37 %.
{"title":"Development of flame retardant coatings containing hexaphenoxycyclotriphosphazene and expandable graphite for carbon fibre-reinforced polyamide 6 composites","authors":"Zsófia Kovács , Andrea Toldy","doi":"10.1016/j.polymdegradstab.2024.111017","DOIUrl":"10.1016/j.polymdegradstab.2024.111017","url":null,"abstract":"<div><div>The increasing importance of thermoplastic composites, driven by their enhanced recyclability and production efficiency, has attracted interest in continuous fibre-reinforced thermoplastic. Polyamide 6 (PA6), synthesised via anionic ring-opening polymerisation, is particularly relevant, however, the flammability of PA6 poses significant challenges and a critical concern for their structural application, necessitating effective flame retardancy measures. This study investigates the development of flame retardant coatings for carbon fibre-reinforced PA6 composites, employing hexaphenoxycyclotriphosphazene (HPCTP) and expandable graphite (EG), and evaluates their efficacy in improving the flammability properties of the composites through their combined modes of action. We investigated the impact of FRs on glass transition temperature, crystallinity, thermal stability, monomer conversion and flammability properties. The best-performing formulations (PA6/3P%HPCTP/3%EG and PA6/3P%HPCTP/4%EG) were applied to the surface of carbon fibre-reinforced PA6 composites by in-mould coating. Due to the synergistic effect of HPCTP and EG, the coatings containing 3P% HPCTP and 3 % EG reduced the maximum heat release by 33 % and the total heat release by 37 %.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111017"},"PeriodicalIF":6.3,"publicationDate":"2024-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1016/j.polymdegradstab.2024.111016
Mingming Yu , Zhimin Gao , Wang Xie , Xiaochao Shi , Ousheng Zhang , Zhigang Shen , Lin Fang , Musu Ren , Jinliang Sun
The oxidation state of phosphorus has a great influence on the flame retardant action of its flame retardants. In this study, a reactive phosphorus-containing flame retardant (POG-DOPO) with both low and high phosphorus oxidation states is synthesised and incorporated into epoxy resin. The results show that the part in high oxidation state act mainly in the condensed phase and the part in low oxidation state act mainly in the gas phase. Furthermore, the flame retardant exhibits a synergistic flame retardant effect, resulting in a higher flame retardant efficiency than that of flame retardants with a single phosphorus oxidation state. Compared with unmodified epoxy resin, the peak heat release rate, total heat release rate and total smoke release of POG-DOPO modified epoxy resin with only 3wt% phosphorus are reduced by 70.9%, 51.2% and 55.7%, respectively. Its LOI increases to 31.8% and vertical combustion test achieves UL-94 V-0 rating. This study provides a strategy for the structural design of efficient phosphorus-based flame retardants.
{"title":"A novel strategy utilizing oxidation states of phosphorus for designing efficient phosphorus-containing flame retardants and its performance in epoxy resins","authors":"Mingming Yu , Zhimin Gao , Wang Xie , Xiaochao Shi , Ousheng Zhang , Zhigang Shen , Lin Fang , Musu Ren , Jinliang Sun","doi":"10.1016/j.polymdegradstab.2024.111016","DOIUrl":"10.1016/j.polymdegradstab.2024.111016","url":null,"abstract":"<div><div>The oxidation state of phosphorus has a great influence on the flame retardant action of its flame retardants. In this study, a reactive phosphorus-containing flame retardant (POG-DOPO) with both low and high phosphorus oxidation states is synthesised and incorporated into epoxy resin. The results show that the part in high oxidation state act mainly in the condensed phase and the part in low oxidation state act mainly in the gas phase. Furthermore, the flame retardant exhibits a synergistic flame retardant effect, resulting in a higher flame retardant efficiency than that of flame retardants with a single phosphorus oxidation state. Compared with unmodified epoxy resin, the peak heat release rate, total heat release rate and total smoke release of POG-DOPO modified epoxy resin with only 3wt% phosphorus are reduced by 70.9%, 51.2% and 55.7%, respectively. Its LOI increases to 31.8% and vertical combustion test achieves UL-94 V-0 rating. This study provides a strategy for the structural design of efficient phosphorus-based flame retardants.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111016"},"PeriodicalIF":6.3,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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