Polymer Degradation and Stability最新文献

{"title":"Mechanical properties, gas permeability and biodegradation mechanism of biobased poly(ester amide)s from 2,5-furandicarboxylic acid and amido diols for sustainable food packaging","authors":"Enrico Bianchi ,&nbsp;Lazaros Papadopoulos ,&nbsp;Michelina Soccio ,&nbsp;Valentina Siracusa ,&nbsp;Massimo Gazzano ,&nbsp;Tobias Robert ,&nbsp;Dimitrios N. Bikiaris ,&nbsp;Nadia Lotti","doi":"10.1016/j.polymdegradstab.2024.111049","DOIUrl":"10.1016/j.polymdegradstab.2024.111049","url":null,"abstract":"<div><div>The aim of this work was to evaluate the functional properties of a family of poly(ester amide)s (PEAs) for flexible food packaging applications. The polymers under study were previously synthesized via random copolymerization of furan 2,5-dicarboxylic acid (2,5-FDCA) with different amounts of 1,10-decanediol and an amido diol (AD 46). Poly(decamethylene furanoate) (PDF) and poly(ester amide) 46 (PEA 46) were the reference homopolymers. PEA copolymers were compression molded into films and subjected to WAXS, DSC, SEM analyses and water contact angle, mechanical, gas barrier tests. The results showed a remarkable improvement in the functional properties of PEAs compared to those of PDF, with a decrease up to about 50% of O₂ and CO₂ transmission rates, which were found to be comparable to those of commercial PET. The mechanical properties of PEAs were also improved in comparison with PDF because of the increased toughness and higher resistance to plastic deformation, paired with elongation at break up to 650%. In order to assess the effects of contact with food, the prepared films were treated with food simulants. Moreover, the films were stored in conditions of controlled temperature and humidity, chosen to replicate real scenarios of application involving aggressive environmental conditions. After contact with food simulant liquids, the materials became more rigid and less ductile, but their gas barrier properties remained superior to those of commercially widespread polyolefins. Finally, films were subjected to composting tests: the higher the amido diol content, the faster the degradation rate, which occurred via a mechanism of bulk hydrolysis, because of the higher hydrophilicity of amide groups. Overall, the results highlighted the potential of PEA copolymers for the production of biobased, sustainable, flexible food packaging.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111049"},"PeriodicalIF":6.3,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538132","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}

{"title":"Pressure-induced formability and degradability of block copolymers composed of poly(1,5-dioxepan-2-one) and poly(L-lactide)","authors":"Hiroto Tada ,&nbsp;Ikuo Taniguchi","doi":"10.1016/j.polymdegradstab.2024.111048","DOIUrl":"10.1016/j.polymdegradstab.2024.111048","url":null,"abstract":"<div><div>An aliphatic polyether/carbonate block copolymer, comprising poly(1,5-dioxepan-2-one) (PDXO, glass transition temperature <em>T</em>_g: -38 °C) and poly(L-lactide) (PLLA, <em>T</em>_g: 55 °C), evinces remarkable formability under pressure at temperatures significantly below the melting point of PLLA. A quantitative and detailed evaluation of the low-temperature molding of the block copolymer was conducted using a capillary rheometer. The findings reveal that block copolymers with PDXO composition &gt;55 wt% demonstrate a propensity to flow at room temperature under 50 MPa pressure. Consequently, the practice of low-temperature molding serves to mitigate the degradation of polymer chains during the molding process, thereby augmenting recyclability. Furthermore, the enzymatic degradability of the block copolymer was extensively investigated using lipase PS and proteinase K. An interplay between the structure of the block copolymer and the degradation kinetics was explored. The polymeric materials developed, possessing both pressure formability and degradability, hold promising potential as environmentally benign polymers with reduced environmental impact.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111048"},"PeriodicalIF":6.3,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554152","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}

{"title":"Stabilization of PE with the natural antioxidant t-resveratrol: Interaction of the primary and the secondary antioxidant","authors":"Kata Takács ,&nbsp;Miklós Ákos Németh ,&nbsp;Tibor Renkecz ,&nbsp;Dóra Tátraaljai ,&nbsp;Béla Pukánszky","doi":"10.1016/j.polymdegradstab.2024.111046","DOIUrl":"10.1016/j.polymdegradstab.2024.111046","url":null,"abstract":"<div><div>The study focuses on the possibility of using resveratrol, a stilbenoid-type natural antioxidant, as a stabilizer in polyethylene. The experiments were carried out in two stages. First, the efficiency of the natural antioxidant was compared to that of a commercial product, and then polymer properties were determined as a function of additive content. Stabilization efficiency was determined by multiple extrusion experiments. Resveratrol proved a very efficient stabilizer, more efficient than the commercial hindered phenolic antioxidant. Resveratrol provides excellent processing stability and the residual stability of PE containing it is exceptional. Because of its large efficiency, 400–500 ppm additive is sufficient to achieve adequate stability for practice. Resveratrol interacts with the secondary phosphorous stabilizer used in the study, and the effect is antagonistic; resveratrol performs better alone than in combination with PEPQ. Accordingly, this unusual effect must be taken into account during formulation and the construction of the actual additive package. Resveratrol is used in other industries, thus it is available in large quantities and relatively cheap. Besides its advantages, the natural antioxidant has some drawbacks, like its high melting temperature, limited solubility in polyethylene, and strong color of its reaction products. Nevertheless, resveratrol has great potential as a stabilizer in certain products.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111046"},"PeriodicalIF":6.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572271","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}

{"title":"Marine durability of carbon black-filled polychloroprene: Effect of seawater ageing on network, tensile and fatigue properties","authors":"H. Madeira ,&nbsp;P.Y. Le Gac ,&nbsp;M. Le Gall ,&nbsp;E. Verron","doi":"10.1016/j.polymdegradstab.2024.111045","DOIUrl":"10.1016/j.polymdegradstab.2024.111045","url":null,"abstract":"<div><div>With the development of marine renewable energies, the durability of materials at sea is more than ever a major issue in reducing the risk of failure of offshore devices. In this aggressive environment, elastomers, and in particular polychloroprene (CR), have many applications because of their good damping and fatigue properties. However, these materials are subject to ageing in service, which leads to changes in their mechanical properties. The ageing of these materials in a marine environment has not been extensively studied, despite the need to predict components lifetimes. This paper investigates the mechanical and microstructural consequences of a carbon black-filled CR degradation when exposed to seawater. To this end, swelling, uniaxial tensile and fatigue tests are carried out on materials previously subjected to accelerated ageing in natural seawater. Particular attention is paid to understanding the physico-chemical phenomena involved, and analysing fracture and fatigue properties in relation to those of the macromolecular network.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111045"},"PeriodicalIF":6.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537995","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}

{"title":"Phosphorus/boron-containing, flame-retardant polyurethane elastomers with great mechanical, shape-memory, and recycling performances","authors":"Tiantian Zhang ,&nbsp;Siqi Huo ,&nbsp;Guofeng Ye ,&nbsp;Cheng Wang ,&nbsp;Qi Zhang ,&nbsp;Yijiao Xue ,&nbsp;Pingan Song ,&nbsp;Hao Wang ,&nbsp;Zhitian Liu","doi":"10.1016/j.polymdegradstab.2024.111047","DOIUrl":"10.1016/j.polymdegradstab.2024.111047","url":null,"abstract":"<div><div>Based on sustainable development strategy and practical application requirement, it is crucial to develop high-strength, recyclable, and flame-retardant polyurethane (PU) elastomers. Hence, a flame-retardant, reprocessable, high-performance polyurethane elastomer (PU-DP 1–7) with dynamic boronic ester bonds and phosphorus-containing groups was well-designed and prepared. The chemical structure of PU-DP 1–7 was confirmed by Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS). PU-DP 1–7 shows a transmittance of about 60 % at the wavelength of 900 nm, and phosphorus and boron elements are evenly distributed within its surface, confirming the formation of uniform cross-linking network. The inclusion of phosphorus-and boron-containing groups endows PU-DP 1–7 with a vertical combustion (UL-94) V-0 rating, indicative of desired flame retardancy. In addition, PU-DP 1–7 exhibits a tensile strength of 42.7 MPa and an elongation at break of 616.9 %, with high adhesion strengths towards various substrates due to abundant hydrogen bonds within its network. Furthermore, the dynamic borate ester bonds endow PU-DP 1–7 with superior physical recycling and shape-memory properties. After hot-pressing at 130 °C, the reformed PU-DP 1–7 film shows an 83.6 % recovery efficiency in terms of elongation at break. This work presents an integrated strategy to create flame-retardant, recyclable polyurethane elastomers with great mechanical and shape-memory performances by introducing phosphorus-containing segments and dynamic boronic ester bonds.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111047"},"PeriodicalIF":6.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538087","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}

{"title":"Characterization of the thermomechanical and aging behaviour of PAEK and CF/PAEK composites under long-term high-temperatures","authors":"Hong-Ru Yang ,&nbsp;Dong-Ting Gao ,&nbsp;Gang Liu ,&nbsp;Chun-Hai Chen ,&nbsp;Jia-Nan Yao","doi":"10.1016/j.polymdegradstab.2024.111043","DOIUrl":"10.1016/j.polymdegradstab.2024.111043","url":null,"abstract":"<div><div>The growing use of poly(aryl ether ketone) (PAEK) polymers reinforced with carbon fiber (CF) aims to meet the increasing demand for thermoplastic composites in applications that require excellent mechanical properties and thermal stability at higher temperatures. This study investigated the physicochemical properties of PAEK and CF/PAEK composites under long-term high-temperature exposure (150 °C, 200 °C and 250 °C) for durations of 15, 30, and 45 days, aiming to elucidate the durability mechanisms and enhance understanding of their performance. Specifically, the changes in the flexural properties and dynamic thermo-mechanical properties of the materials were evaluated after long-term high-temperature treatment. The results indicated that both PAEK and CF/PAEK composites possess substantial potential for long-term high-temperature applications, with CF not significantly altering the fundamental high-temperature response of the PAEK matrix. Regarding durability mechanisms, at 150 °C, PAEK's amorphous region undergoes chain reorientation, while temperatures of 200 °C and 250 °C induce significant secondary crystallization, which significantly improved the high-temperature mechanical properties of these materials. Additionally, at temperatures up to 250 °C, shorter linear chain fragments form through oxidative scission in PAEK's amorphous molecular chains. This work not only enriches the existing data on the properties of PAEK and CF/PAEK composites after long-term high-temperature treatment, but also provides further insights into their durability mechanisms.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111043"},"PeriodicalIF":6.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538086","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}

{"title":"Embrittlement induced by oxidation in polyethylene: Role of initial bimodality","authors":"R. Laot ,&nbsp;P.-Y. Le Gac ,&nbsp;M. Le Gall ,&nbsp;M. Broudin ,&nbsp;C. Ovalle ,&nbsp;L. Laiarinandrasana","doi":"10.1016/j.polymdegradstab.2024.111025","DOIUrl":"10.1016/j.polymdegradstab.2024.111025","url":null,"abstract":"<div><div>High density polyethylene films (200 µm) with an initial bimodal chain length distribution were aged in ovens at 60 °C, 70 °C, and 80 °C. Oxidation effects were characterized at the macromolecular scale to measure the chain length distribution, the amount of crystalline phase, the type of crystallites, and the thickness of the amorphous layer. Additionally, mechanical properties were measured using tensile tests. Regardless of the aging temperature, the same behavior was observed: bimodal chain length distribution became unimodal, the crystallinity ratio increased, the amorphous layer thickness decreased, and the polyethylene became brittle. The embrittlement of the polymer is discussed, and two criteria are proposed: a critical molar mass and a critical amorphous layer thickness. The latter appears to be independent of the initial chain length distribution of the polyethylene.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111025"},"PeriodicalIF":6.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537994","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}

{"title":"Catalyst-free sustainable epoxy vitrimers with fire safety offered by phosphorus-containing compounds","authors":"Fubin Luo,&nbsp;Shuguang Yang,&nbsp;Xueyan Yang,&nbsp;Yixin Feng,&nbsp;Bili Lin,&nbsp;Yingbing Zou,&nbsp;Hongzhou Li","doi":"10.1016/j.polymdegradstab.2024.111042","DOIUrl":"10.1016/j.polymdegradstab.2024.111042","url":null,"abstract":"<div><div>In this study, we designed and incorporated a phosphorus-rich compound, DPT, which possesses inherent catalytic properties, into a typically sustainable epoxy vitrimer. This innovative strategy enables the fabrication of flame retarded epoxy vitrimers that require no additional catalysts. DPT was synthesized through a reaction between triethanolamine (TEA) and dibenzyl chlorophosphonate (DPCP). The successful synthesis of DPT is attested to by FTIR and NMR analyses. DPT effectively accelerated the curing process of the epoxy vitrimers, yielding materials with exceptional mechanical strength and inherent self-healing abilities. Notably, the pHRR of epoxy vitrimer incorporated with DPT is reduced to 296.3 kW/m², showing a remarkable 54% reduction compared to that of the epoxy vitrimer catalyzed by conventional catalysts. The THR is also decreased from 84.3 to 42.4 MJ/m². Comprehensive analyses using cone calorimetry and TG-FTIR revealed that DPT effectively inhibits the emission of toxic gases. Crucially, the presence of DPT in the epoxy matrix facilitated the formation of a dense and stable phosphorus-laden carbon layer, which not only enhanced flame retardancy but also imparted exceptional smoke suppression capabilities. These findings underscore the potential of DPT for developing high-performance, catalyst-free, flame-retardant epoxy vitrimers.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111042"},"PeriodicalIF":6.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537993","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}

{"title":"One- and two-step synthesis of paramylon mixed ester derivatives and the substitution effect on mechanical properties and seawater biodegradability","authors":"Ruiqi Li,&nbsp;Jin Ho Seok,&nbsp;Tadahisa Iwata","doi":"10.1016/j.polymdegradstab.2024.111037","DOIUrl":"10.1016/j.polymdegradstab.2024.111037","url":null,"abstract":"<div><div>Paramylon acetate hexanoate (PaAcHex) with total DS=1.7 was prepared by one- and two-step methods with acetylation and hexanoylation in different order (denoted as AcHex and HexAc) in homogeneous DMAc/LiCl. The distribution of substitution at various ring carbon atoms (C2, C4, and C6) of PaAcHex synthesized by different methods was determined by ¹H NMR spectroscopic analysis. The AcHex mixed esters showed a higher DS of long-chain Hex on C2 and C4 than the other samples. All mixed esters were amorphous and their glass transition temperatures (<em>T</em>_g) were obtained from DMA measurements. PaAcHex with higher DS of hexanoate groups had lower <em>T</em>_g and their melt films showed higher flexibility at the same total DS for all three series of samples. PaAcHex films produced by the two-step (AcHex) method exhibited high toughness even with a low DS of hexanoate groups, whereas those synthesized by the one-step and two-step (HexAc) methods were weak and brittle. Biochemical oxygen demand tests indicated that the mixed esters prepared by the two-step (AcHex) method underwent a two-step degradation process, which may be related to the hexanoate groups on C2 and C4. Short–long chain acylation by the two-step (AcHex) method was found to be the optimal synthesis technique for polysaccharide esters that displayed favorable thermoplasticity and controllable seawater biodegradation behavior. These polysaccharide esters show promise as bioplastic materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111037"},"PeriodicalIF":6.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537990","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}

{"title":"Highly efficient flame retardancy and fire spread behavior of rigid polyurethane foams with extremely low content of flame retardant","authors":"Liwen Zheng ,&nbsp;Jing Zhan ,&nbsp;Jiahui Wang ,&nbsp;Zhirong Xu ,&nbsp;Xiaowei Mu","doi":"10.1016/j.polymdegradstab.2024.111039","DOIUrl":"10.1016/j.polymdegradstab.2024.111039","url":null,"abstract":"<div><div>In recent years, flame-retardant rigid polyurethane foam (RPUF) has once again captured the scholars’ attention due to the growing the growing demands in the field of building energy efficiency. However, the inherent flammability of RPUF is high and the complexities of its flame-retardant mechanisms remain inadequately understood. In this study, a modified biomass material, amino starch phosphate ester was successfully synthesized which was then combined with expandable graphite (EG) and incorporated into RPUF. The research delved into the optimal ratio and minimal flame-retardant additive required to achieve the stringent UL-94 V-0 rating, while also thoroughly investigating the flame retardancy and thermal properties of the composite system. The findings revealed that with just 6 wt.% of flame retardants, the RPUF achieved the UL-94 V-0 rating, with a 41.1 % reduction in peak heat release rate (pHRR) and a 23.7 % decrease in total heat release (THR). Additionally, it diminishes the flame's size and width, leading to quicker extinction, while also lowering the internal combustion temperature of the polyurethane, thereby delaying both preheating and combustion times. The synergistic interaction between amino starch phosphate ester and EG during combustion results in the formation of a dense, continuous char layer, effectively inhibiting the pyrolysis and combustion of RPUF. This study provides a theoretical foundation for the development of efficient flame-retardant systems for RPUF.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111039"},"PeriodicalIF":6.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538089","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}