Zhenggui Wu , Yanan Li , Hongmei Chen , Xinyi Dong , Qingfei Duan , Xudong Hao , Long Yu
{"title":"Investigation of microplastics from granulated virgin and UV aged samples in artificial digestion system","authors":"Zhenggui Wu , Yanan Li , Hongmei Chen , Xinyi Dong , Qingfei Duan , Xudong Hao , Long Yu","doi":"10.1016/j.polymdegradstab.2024.111157","DOIUrl":"10.1016/j.polymdegradstab.2024.111157","url":null,"abstract":"<div><div>The environmental concerns of microplastics (MPs) have attracted increasing attention due to their potential harm to human health. However, most of the MPs used in previous studies are from virgin materials through artificial granulation, as it is almost impossible to collect the natural MPs from nature and accurately identify their sources or ages. It is anticipated that the MPs after UV aging possess some major distinct characteristics similar as aged in nature, including variations in molecular weight, molecular weight distribution, surface chemicals. This study systematically investigated both virgin and UV aged samples derived from the most prevalent sources, including polyethylene (PE), polypropylene (PP), poly(ethylene terephthalate) (PET), polystyrene (PS), and poly(vinyl chloride) (PVC), focusing on the effects of the artificial digestion system on the MPs. Additionally, the study evaluated the impact of these MPs on health by examining their effects on probiotics within the digestive system. The results demonstrate that both the effect of digestion treatment MPs and the impact of MPs on intestinal microbiota are significantly different between virgin and aged MPs. While digestion processes were ineffective in degrading virgin MPs, primarily due to their chemical inertness, the surface changes in MPs were more pronounced after UV aging, though they remained largely unaffected by digestion. The surface chemical changes were significant during aging but not during digestion. On the other hand, certain MPs, particularly PVC, may disrupt the balance of intestinal microbiota, especially from aged samples.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111157"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182811","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":"Defining the degree of degradation in plastics: Quantification of accumulated degradation products and leached stabilizers for predicting end-of-life","authors":"Yusuke Hibi , Tsukasa Matsumoto , Masatoshi Midorikawa , Shiho Uesaka , Makoto Mizoshiri , Toshiyuki Tanimura , Masato Okada , Kimiyoshi Naito , Masanobu Naito","doi":"10.1016/j.polymdegradstab.2024.111128","DOIUrl":"10.1016/j.polymdegradstab.2024.111128","url":null,"abstract":"<div><div>Plastics degrade through various mechanisms, complicating the comprehensive chemical definition of degradation. As the accumulation of degraded products leads to sudden declines in material properties and triggers microplastic dispersion, a chemical degradation metric is essential for predicting plastics’ end-of-life. Here, we propose defining degradation by the weight ratio of “completely degraded polymer (CDP)” to pristine polymer, determined via pyrolysis mass spectrometry (MS). By simplifying the complex degradation evaluation into a straightforward framework of compositional analysis, a comprehensive degradation metric can be obtained without tracking individual degradation pathways. Moreover, by including stabilizers as system components, stabilizer leaching and polymer degradation can be concurrently visualized in the same framework. We demonstrate this approach in polyurethane films subjected to accelerated degradation tests and, by correlating the CDP-defined degradation metric with mechanical property evaluations, successfully identify the threshold degradation level that marks a material's end-of-life. Furthermore, this method reveals deeper insights into degradation mechanisms: stabilizer leaching and polymer degradation are complementary processes that induce each other. This comprehensive degradation metric will also be crucial for grading recycled materials, promoting the circular economy in plastics.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111128"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181545","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":"Improvement of the durability of hydrogenated nitrile butadiene rubber sheets by adding phosphorylated cellulose nanofibers and metal (meth)acrylate","authors":"Toru Noguchi , Yasuo Bamba , Jun Sakurai , Morinobu Endo , Akira Isogai","doi":"10.1016/j.polymdegradstab.2024.111158","DOIUrl":"10.1016/j.polymdegradstab.2024.111158","url":null,"abstract":"<div><div>Nanocellulose materials are expected to partly replace petroleum-derived carbon black in rubber composites for the short-term improvement of their properties. In this study, phosphorylated cellulose nanofibers (P-CNFs) and hydrogenated nitrile-butadiene rubber (H<img>NBR) were oven-dried with or without metal (meth)acrylates, and the once-dried mixtures were kneaded and pressed to prepare cross-linked H<img>NBR/P-CNF/metal (meth)acrylate composite sheets. Neat H<img>NBR and carbon-black-containing H<img>NBR composite sheets were prepared as references. In addition to the tensile and dynamic thermomechanical properties, the, hardness, abrasion resistance, degree of hysteresis loss, and hot water/organic solvent resistance of the composite sheets were evaluated. The properties of the P-CNF containing composite sheets were better than those of the neat H<img>NBR sheet and carbon-black-containing composite sheets at the same P-CNF or carbon black content. The H<img>NBR/P-CNF/zinc methacrylate composite sheets showed the best performance in terms of not only the above properties, but also the hot water resistance, tensile properties, and abrasion resistance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111158"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182807","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}
Yan-Dong Hu , Yan-Bei Hou , Kang-Si Zhou, Wei-Zhao Hu, Fu-Kai Chu, Lei Song, Yuan Hu
{"title":"An insight into the effects of the low oxidation states of phosphorous on the combustion behavior of intrinsically flame-retardant unsaturated polyester resins","authors":"Yan-Dong Hu , Yan-Bei Hou , Kang-Si Zhou, Wei-Zhao Hu, Fu-Kai Chu, Lei Song, Yuan Hu","doi":"10.1016/j.polymdegradstab.2024.111156","DOIUrl":"10.1016/j.polymdegradstab.2024.111156","url":null,"abstract":"<div><div>To mitigate the migration of flame retardants in unsaturated polyester resins (UPR), flame-retardant structures can be integrated into the molecular chain to create intrinsically flame-retardant UPR. Variations in the oxidation states of phosphorus-containing flame retardants can influence the distribution of phosphorus-containing compounds between the gas and condensed phases during combustion, thereby affecting the flame-retardant performance and mechanisms. Building on previous studies of the impact of phosphorus-containing flame retardants with high oxidation numbers on UPR's combustion behavior and flame-retardant mechanism, this research further investigated the effects of phosphorus-containing structures with -1 and +1 oxidation states on the pyrolysis, heat release, smoke emission, and char formation of intrinsically flame-retardant UPR. Two kinds of itaconic acid-based phosphorus-containing dicarboxylic acids were synthesized and incorporated into the polyester backbones of UPR. Pyrolysis and combustion tests were performed to elucidate the combustion behavior regulation mechanisms of intrinsically flame-retardant UPR with low oxidation numbers. Findings indicate that both of the phosphorus-containing dicarboxylic acids exhibit strong flame inhibition, implying a dominant gas-phase mechanism. Moreover, they effectively shorten the duration of the release of the pyrolysis gases. However, the difference in oxidation states didn't result in a huge difference in their flame inhibition, and it's the condensed phase mechanism that makes the difference in their performance. FRUP2 with stable char layers demonstrates better flame retardancy. This study offers practical and efficient guidance for designing intrinsically flame-retardant UPR with high performance by elucidating the structure-performance relationship of phosphorus-containing compounds with low oxidation numbers.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111156"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182810","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":"The synthesis and properties of an intumescent zinc-chelated organometallic flame retardant","authors":"Tianyu Liu, Ying Tao, Xiuyuan Ni","doi":"10.1016/j.polymdegradstab.2024.111142","DOIUrl":"10.1016/j.polymdegradstab.2024.111142","url":null,"abstract":"<div><div>Organometallic flame retardants (OFRs) are currently attracting intensive attention. Here, we synthesized a new zinc-chelated OFR, ZnDSi, which was incorporated with phosphorus, silicon, and nitrogen functional moieties. The resulting ZnDSi exhibited strong intumescent properties upon heating and demonstrated high thermal stability, with a decomposition temperature (T<sub>d, 5 %</sub>) of 349 °C, making it suitable for the melt-processing of most engineering plastics. Comparative experiments demonstrated that the chelated zinc converted the properties of the resultant OFR, including its intumescence, thermostability and hydrophobicity. The ZnDSi was tested in polyamide 66 (PA66) for the flame-retardant properties. Incorporating 10 wt% of ZnDSi into PA66 attained a limiting oxygen index of 29.1 %, accompanied by the reduction of the peak heat release rate by 35.0 % and total heat release by 28.2 % when compared to the pure PA66 sample, according to the cone calorimeter tests. Mechanism investigation was conducted to probe into the interactions between zinc and organic components through a custom apparatus for pyrolytic gas analysis, and it was found that zinc could reduce the soot release by suppressing the formation of the soot precursors during the pyrolysis. This work contributes to a deeper understanding of how metal elements function in OFR systems, which may conduce to developing OFRs with advanced performance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111142"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181549","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":"Enhancing stability: The protective role of nanodiamonds against biodegradation in cellulose ethers dispersions","authors":"Elena Palmieri , Annamaria Alabiso , Luciana Migliore , Claudia Mazzuca , Emanuela Tamburri , Valeria Guglielmotti , Silvia Orlanducci","doi":"10.1016/j.polymdegradstab.2025.111247","DOIUrl":"10.1016/j.polymdegradstab.2025.111247","url":null,"abstract":"<div><div>This study investigates the effect of detonation nanodiamonds (DND) in preserving cellulose dispersions, specifically hydroxyethyl cellulose (HEC) and hydroxypropyl cellulose (HPC) solutions, by analyzing their rheological behavior, chemical-physical properties, and degradation resistance. HEC and HPC are widely used cellulose ethers with thickening, stabilizing, and water-retaining properties, making them valuable in cosmetics, electronics, pharmaceuticals, and other industries. However, these polymers degrade under harsh conditions and are prone to microbial contamination in aqueous systems. The results demonstrate that incorporating DND into cellulose ether formulations significantly enhances their stability and reduces biodegradation risks. Viscosity measurements show slower depolymerization rates in DND-containing dispersions, indicating a longer shelf life than pure HEC or HPC solutions. Additionally, pH fluctuations are more controlled in composites, with a maximum variation of only 1 pH unit compared to 2.5 units in standard solutions, suggesting improved chemical stability. Conductivity changes due to degradation are minimal in DND formulations, indicating reduced breakdown over time. Notably, microbial growth is drastically reduced in DND composites.</div><div>These findings highlight DND's role in improving cellulose ether solutions' durability, functionality, and shelf life, offering significant benefits for industries that rely on these materials by ensuring enhanced product stability and prolonged performance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"234 ","pages":"Article 111247"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094519","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}
M. Andruschko , M. Luksin , P. Frank , T. Paululat , U. Jonas , S. Fuchs
{"title":"A set of intrinsically flame retardant, halogen-free styrenic copolymers: Synthesis, characterization, processing, and properties","authors":"M. Andruschko , M. Luksin , P. Frank , T. Paululat , U. Jonas , S. Fuchs","doi":"10.1016/j.polymdegradstab.2024.111141","DOIUrl":"10.1016/j.polymdegradstab.2024.111141","url":null,"abstract":"<div><div>Halogen-free, intrinsically flame retardant copolymers with glass transition temperatures in the range of 93 - 97 °C were synthesized from styrene, elemental sulfur, and organophosphorus comonomers in a facile radical bulk polymerization process. The copolymers were characterized using multidetector size exclusion chromatography (SEC), elemental analysis (EA), thin layer chromatography (TLC), UV/Vis spectroscopy, and <sup>1</sup>H, <sup>13</sup>C, and <sup>31</sup>P nuclear magnetic resonance (NMR) spectroscopy. SEC revealed number average molar masses (M<sub>n</sub>) ranging from 14 - 18 kg/mol, and weight average molar masses (M<sub>w</sub>) from 41 - 62 kg/mol. The phosphorus contents ranged from 0.1 - 0.6 wt.%, while the sulfur contents were 0.4 - 0.7 wt.%, with covalently bound sulfur being predominantly present in the lower molar mass fractions. Structural details of the formed sulfur-containing moieties in the copolymers were elucidated with homonuclear correlation spectroscopy (COSY) and <sup>1</sup>H/<sup>13</sup>C heteronuclear single-quantum correlation spectroscopy (HSQC) techniques, indicating the presence of PS-substituted 1-phenylethyl sulfanyl units with a mono-, di- or trisulfidic arrangement. Thermogravimetric analyses (TGA) showed slightly decreased decomposition onset temperatures for all copolymers compared to that for polystyrene, and no or only minimal formation of residual masses above 500 °C. Selected copolymers were extruded and injection molded on a laboratory scale. UL 94 vertical flame testing demonstrated a good flame retardant performance for most copolymer types, alongside with short after-flaming times and intensive melt dripping. Increased melt flow caused by polymer decomposition, probably initiated by the sulfur moieties in the copolymer structures, and cooling are considered the main condensed-phase flame retardant processes involved. Two copolymers of the set display a UL 94 V-0 classification.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111141"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182812","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}
Zhishuo Liu , Yifang Hua , Suqin Liu , Hongfei Li , Xiaoyu Gu , Jun Sun , Sheng Zhang
{"title":"In-situ co-precipitation synthesis of Zn/Fe-LDH modified melamine polyphosphate for enhanced flame retardancy in polypropylene","authors":"Zhishuo Liu , Yifang Hua , Suqin Liu , Hongfei Li , Xiaoyu Gu , Jun Sun , Sheng Zhang","doi":"10.1016/j.polymdegradstab.2024.111147","DOIUrl":"10.1016/j.polymdegradstab.2024.111147","url":null,"abstract":"<div><div>In this study, a novel approach was employed to enhance the flame retardant efficiency of an intumescent flame retardant (IFR) by growing a layered double hydroxides (LDHs) of Zn/Fe on the surface of melamine polyphosphate (MPP), denoted as Zn/Fe-LDH@MPP (LDHMPP). This modification was carried out via in-situ co-precipitation, and the resulting composite was subsequently applied to polypropylene (PP) in conjunction with piperazine pyrophosphate (PAPP). Under the same proportion and concentration, the PP/16 %LDHIFR formulation achieved a preferred V-0 rating in the UL-94 test. Furthermore, this formulation exhibited an enhanced ability to form a protective char layer, as evidenced by both cone calorimetry tests (CCT) and thermogravimetric analysis (TGA) tests. Additionally, the synergistic effect of Zn/Fe-LDH on flame retardancy was also studied.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111147"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183395","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":"Performance comparison and lifespan assessment of naturally and artificially chalked silicone rubber for composite insulators","authors":"Shiyin Zeng, Xin Zhao, Wendong Li, Yanan Peng, Yuelin Liu, Xinyi Yan, Guanjun Zhang","doi":"10.1016/j.polymdegradstab.2024.111139","DOIUrl":"10.1016/j.polymdegradstab.2024.111139","url":null,"abstract":"<div><div>Chalking is a typical manifestation of high-temperature vulcanized silicone rubber (HTV-SR) deterioration for composite insulators. Previous studies have proposed an efficient artificial chalking method based on tetramethylammonium hydroxide (TMAH), but the quantified equivalence between artificial and natural chalking, particularly in terms of electrical properties, remains underexplored. In this paper, 5 naturally chalked (NC) samples with different lifespans and 5 artificially chalked (AC) samples with different TMAH concentrations are prepared. Then surface morphology, structure, mechanical and electrical properties of chalked samples are methodically characterized. The results indicate that the overall performance of the two kinds of chalking surfaces is similar, but AC samples treated with high TMAH concentration exhibits severe chalking. Besides, the NC process is driven by both filler precipitation and oxidative crosslink, whereas the AC process lacks internal oxidation. Further analysis based on quantum chemistry calculations reveals the silanol produced during chalking has a narrow-forbidden gap and deep traps, which degrades the electrical properties. Finally, a lifespan assessment method with 8 chalking indexes is constructed and the optimal Ridge Regression model is selected to comprehensively assess lifespans of AC samples. This study explores the chalking characteristics of NC samples, and also offers manufacturers an efficient way to evaluate the chalking resistance of new HTV-SR.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111139"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182504","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}