Polymer Degradation and Stability最新文献

{"title":"Recycling of EPDM rubber via thermomechanical devulcanization: Batch and continuous operations","authors":"Dávid Zoltán Pirityi ,&nbsp;Tamás Bárány ,&nbsp;Kornél Pölöskei","doi":"10.1016/j.polymdegradstab.2024.111014","DOIUrl":"10.1016/j.polymdegradstab.2024.111014","url":null,"abstract":"<div><div>Thermomechanical devulcanization is a possible solution for the circular economy of EPDM rubber, as it removes covalent crosslinks from vulcanizates, resulting in a material similar to uncured rubber mixes. In this paper, sulfur-cured EPDM rubber was treated with thermomechanical stimuli: a) processing on a two-roll mill and in an internal mixer, and b) twin-screw extrusion. Horikx's analysis indicated a 75 % decrease in crosslink density with little polymer chain degradation. The resulting devulcanizates and non-devulcanized rubber crumb were added to the original rubber mix, yielding samples with 0, 25, 50, 75 and 100 wt% recycled rubber contents. Revulcanizates with up to 50 wt% devulcanizate content retained the tensile strength of the original rubber with a slight increase in modulus. Ultimately, batch devulcanization had the most promising results, and extrusion devulcanization was also more beneficial than using non-devulcanized rubber crumb. Crosslink density and morphological tests also support these findings.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111014"},"PeriodicalIF":6.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319135","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":"Synthesis of renewable and seawater-degradable polyesters based on a fully biobased diester","authors":"Jinyan Li,&nbsp;Yang Yu,&nbsp;Xiaolin Zhang","doi":"10.1016/j.polymdegradstab.2024.111015","DOIUrl":"10.1016/j.polymdegradstab.2024.111015","url":null,"abstract":"<div><div>The design and development of biobased plastics that can degrade in seawater is a potential approach to address the seawater pollution of fossil plastics. Herein, <em>N,N</em>'-pentamethylene-bis(pyrrolidone-4-methyl carboxylate) (PBPC), a biobased diester with two pyrrolidone rings, was synthesized from renewable 1,5-pentanediamine and dimethyl itaconate. PBPC was polymerized with three α,ω-diols to prepare biobased homopolyesters with number-average molecular weight (<em>M</em>_n) around 25 kDa. These amorphous homopolyesters presented remarkable UV shielding abilities compared with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS). Incubation experiments in artificial seawater for 150 days indicated that the homopolyesters based on PBPC exhibited rapid seawater-degradability. Then, PBPC was copolymerized with 1,4-butanediol and terephthalic acid to prepare a series of copolyesters with <em>M</em>_n around 20 kDa. The introduction of PBPC into poly(butylene terephthalate) (PBT) resulted in the elevated toughness and sensitivity to seawater degradation. Depending on the composition of PBPC, the thermal, mechanical, and degradation rate of the copolyesters were adjustable. Overall, the PBPC-based polyesters are promising alternatives to commercial packaging materials in improving the renewability of raw materials and achieving seawater degradation.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111015"},"PeriodicalIF":6.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314157","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":"Engineering sulfonated carbon black for flame-retardant and smoke-suppressive polycarbonate with well-preserved mechanical performances","authors":"Xiaodi Ye ,&nbsp;Cheng Zhan ,&nbsp;Bingtao Wang ,&nbsp;Ting Sai ,&nbsp;Chengfeng Zhang ,&nbsp;Juan Li ,&nbsp;Zhenghong Guo ,&nbsp;Siqi Huo","doi":"10.1016/j.polymdegradstab.2024.111012","DOIUrl":"10.1016/j.polymdegradstab.2024.111012","url":null,"abstract":"<div><div>To cope with the practical demands of high-performance polycarbonate (PC) and explore the application of carbon black (CB) in flame retardant field, a sulfonated carbon black (CB-SS) was synthesized and applied to flame retardant PC in this work. Compared with PC/CB composite, PC/CB-SS composite displays better overall performances under the same flame retardant addition. The PC/3CB-SS composite with 3 wt.% of CB-SS achieves a vertical burning test (UL-94) V-0 rating with a limiting oxygen index (LOI) of 29.5%, and its peak heat release rate (PHRR) and total smoke release rate (TSR) are respectively reduced by 17% and 6% relative to those of PC/3CB with 3 wt.% of CB. The flame retardancy mechanism is proposed by analyzing the char residue obtained from cone calorimetry test, which confirms the synergistic flame-retardant effect between sodium sulfonate and CB in condensed phase. Moreover, PC/3CB-SS shows much better mechanical properties than PC/3CB, and its elongation at break is increased by 223% compared with that of PC/3CB. This is mainly due to the more even dispersion of CB-SS within PC and the stronger interfacial force between CB-SS and PC. This work provides an effective approach for the creation of fire-retardant and smoke-suppressive PC composites with well-preserved mechanical properties, contributing to expanding the industrial applications of PC.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111012"},"PeriodicalIF":6.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314163","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 preparation of ammonium polyphosphate@ nickel/cobalt-layered double hydroxide and its application as flame retardant in thermoplastic polyurethane","authors":"Xiao-Hui Shi ,&nbsp;Huan Luo ,&nbsp;Cheng-Yue Jing ,&nbsp;Hong Shi ,&nbsp;De-Yi Wang","doi":"10.1016/j.polymdegradstab.2024.111013","DOIUrl":"10.1016/j.polymdegradstab.2024.111013","url":null,"abstract":"<div><div>Inspired by the significant synergistic effect of transition metals and ammonium polyphosphate (APP) on flame reatrdancy, a nickel/cobalt-layered double hydroxide derived from a selected zeolitic imidazolate framework-67 (APP@NiCo) was constructed onto the surface of APP to enhance the fire safety of thermoplastic polyurethane (TPU). The results demonstrated that TPU containing 6 wt% APP@NiCo exhibited a LOI value of 27.7 % and achieved UL-94 V-0 rating. Furthermore, there was a significant reduction in the peak heat release rate, heat release rate, and total smoke production by 72.8 %, 37.5 % and 56.9 %, respectively. The remarkable improvement in flame retardancy was contributed to the highly synergistic charring catalysis of APP and dual transition metals cobalt and nickel, which effectively promoted the formation of robust char layers during TPU combustion for enhancing fire safety.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111013"},"PeriodicalIF":6.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319134","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":"Simultaneously boosting the flame retardancy and degradability of poly(lactic acid) composite by phosvitin affiliation","authors":"Zhaoshun Zhan ,&nbsp;Shihan Weng ,&nbsp;Tianyou Bao ,&nbsp;Lina Yan ,&nbsp;Fanna Meng ,&nbsp;Lixin Li","doi":"10.1016/j.polymdegradstab.2024.111010","DOIUrl":"10.1016/j.polymdegradstab.2024.111010","url":null,"abstract":"<div><div>Currently, it is still a challenge to endow polylactic acid (PLA) with excellent degradation and fire safety. In this work, we have extracted a novel phosvitin aiming to achieve the fire resistance and degradation of PLA. Employing the phosvitin, the PLA composite exhibits conspicuous fire resistance with an LOI of 27.4 % and a V-0 rating in the UL-94 tests by controlling the added volume at 40 wt.%. Simultaneously, the thermal stability and fire behaviour of the PLA composite have been improved by the plentiful char residue formation. The flame-retardant mechanism of phosvitin in PLA material has been deduced by TG-IR, FTIR XPS and SEM. The phosvitin containing abundant P-O, <em>P</em> = <em>O</em> and P-N functional groups generates phosphorus-containing compounds to promote the dehydration reaction of the PLA matrix in a condensed phase. This is beneficial to improve the flame retardancy of PLA by the formation of a char layer, providing the shielding effect to prevent the heat transfer and flammable micro-molecules volatilisation process. Likewise, the affluent phosphorus-containing compounds included in the phosvitin possess fabulous catalytic action to destroy the PLA into small molecular weight fragment which shows a beneficial to promote the degradation reaction of PLA composite. Hence, the phosvitin is important to expand the range of applications of PLA materials to develop sustainable multifunctional materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111010"},"PeriodicalIF":6.3,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311563","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":"“Three birds with one stone” strategy for building easily reprocessable cellulosic thermosetting resins","authors":"Tengfei Han ,&nbsp;Yanshai Wang ,&nbsp;Shufen Zhang ,&nbsp;Benzhi Ju","doi":"10.1016/j.polymdegradstab.2024.111009","DOIUrl":"10.1016/j.polymdegradstab.2024.111009","url":null,"abstract":"<div><div>Cellulose is the most abundant natural polypolysaccharide and is an ideal raw material to replace petroleum-based plastics. However, natural cellulose is difficult to be thermo-processed like conventional plastics because of the rich and strong hydrogen bonds interactions. In this study, a series of dialdehyde derivatives of cellulose (DACs) were prepared by periodate oxidation of cellulose, and cellulose covalent adaptive networks based on acetal dynamic covalent bonds (ACCs) were prepared using dipentaerythritol as a crosslinker for DAC. This strategy can introduce acetal bonds, weaken hydrogen bonds, and reduce rigidity to kill three birds with one stone. The excellent reprocessing performance of ACCs is attributed to the reconstruction of the cellulose hydrogen bond network by acetal bonds, and the reversible exchange reaction of the acetal bonds at high temperatures endows the cellulose chains with mobility, allowing ACCs to be remodeled by hot pressing at 90°C for 15 min. The excellent stability and reprocessability of ACCs hold the promise of replacing current non-renewable petroleum-based plastics and provide inspiration for the development of other types of biomass plastics.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111009"},"PeriodicalIF":6.3,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311562","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":"Isolation and characterization of a novel bacterium that promotes the degradation of poly(glycolic acid) by its extracellular esterase under thermophilic conditions","authors":"Takuma Kobayashi ,&nbsp;Toshiaki Nakajima-Kambe","doi":"10.1016/j.polymdegradstab.2024.111007","DOIUrl":"10.1016/j.polymdegradstab.2024.111007","url":null,"abstract":"<div><p>Poly(glycolic acid) (PGA) is widely utilized in the shale oil and gas industry owing to its biodegradable nature, as well as superior mechanical and barrier properties. However, PGA degradability is limited by environmental conditions such as temperature and pH, and using acids to optimize the degradation can have adverse environmental impact. Thus, it is essential to identify methods that can effectively promote the degradation of PGA under mild conditions, such as microbial degradation. In the present study, strain DB14, a bacterium that promotes PGA degradation, was isolated from drain water of a steam pipeline. Sequence analysis of the 16S rRNA gene of the bacterium revealed that it is mostly closely related to <em>Geobacillus icigianus</em>; however, it also differed from <em>Geobacillus icigianus</em> in several physiological properties. To investigate PGA degradation by strain DB14, a PGA film and disc were incubated with the strain. The residual weight of the PGA film (thickness: 170 μm) significantly reduced after incubation, whereas the decrease in the thickness of the PGA disc (thickness: 3 mm) was relatively small. The penetration of water, the bacterium, and the extracellular enzymes into the interior from the reaction-erosion front of the PGA disc may be inhibited by the high barrier performance of PGA. Strain DB14 was also found to change the pH of the surrounding environment to approximately 8–9. To investigate the effect of pH on PGA degradability, degradation tests with crude extracellular enzymes derived from strain DB14 were conducted in various buffers. The results showed that the degradation activity was highest at pH 8, which implied that DB14 efficiently maximized the hydrolytic capacity of its enzyme for degrading PGA. Thus, this study provides a basis for developing environmentally friendly technologies that can promote the degradation of PGA molding articles, especially those used in wellbores for oil and gas recovery.</p></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 111007"},"PeriodicalIF":6.3,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271236","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":"Deeper insights into flame retardancy of polymers by interpretable, quantifiable, yet accurate machine-learning model","authors":"Ran Wang,&nbsp;Teng Fu,&nbsp;Ya-Jie Yang,&nbsp;Xiu-Li Wang,&nbsp;Yu-Zhong Wang","doi":"10.1016/j.polymdegradstab.2024.110981","DOIUrl":"10.1016/j.polymdegradstab.2024.110981","url":null,"abstract":"<div><div>Fire-safety polymer materials are essential in modern society such as electronics, aerospace, new energy. The quantification and prediction of flame retardancy, determined by the chemical composition and the burning process, has always been a bottleneck challenge. Previous empirical design rules and the existing models show large deviations for predicting flame retardancy and are often unexplainable. Here, this study proposes an interpretable model that can quantify the groups contribution of flame-retardancy and predict the flame retardance of intrinsically flame-retardant polymers. The machine learning model simultaneously considers the group structures and their flame-retardant mechanism in both the gas phase and condensed phase, achieving high prediction accuracy (89.8% for the training set and 83.8% for the testing set). It also quantifies the contribution values of various flame-retardant groups (halogen-containing structures, phosphorus-containing structures, phosphorus-nitrogen-containing structures, aromatic ring-containing structures, etc.) in both phases for the first time. The running script that integrates the model has also been open-sourced, providing an emerging strategy for transitioning flame-retardant research from empirical methods to scientific design.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"230 ","pages":"Article 110981"},"PeriodicalIF":6.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311423","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":"Flammability and thermal analysis of vertically oriented polyvinyl alcohol/DOPO derivative/MXene composite aerogel","authors":"Ying Zhou ,&nbsp;Weidi He ,&nbsp;Jiling Song ,&nbsp;Dinghong Xu ,&nbsp;Hongmin Wu ,&nbsp;Jianbing Guo","doi":"10.1016/j.polymdegradstab.2024.111006","DOIUrl":"10.1016/j.polymdegradstab.2024.111006","url":null,"abstract":"<div><p>The fabrication of ultralight high-performance flame-retardant composites significantly reduces fire risk for buildings. Flame retardation of porous polyvinyl alcohol (PVA) aerogels with directional arrangement is difficult. Herein, the polyvinyl alcohol/ 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative/two-dimensional (2D) MXene (PVA/DiDOPO/MXene) composite aerogel was prepared by ice template one-way freezing process. PVA-DiDOPO4 composite aerogel with an oriented porous structure reaches the V-1 level at the UL-94 test. Moreover, the peak heat release rate (pHRR) value of PVA-DiDOPO4 reduces to 452.26 (W/g) from 482.88 (W/g) of pure PVA. In addition, PVA/DiDOPO/MXene composite aerogel has improved thermal decomposition properties such as the maximum decomposition temperature (T_max1) of the PVA-DiDOPO4 sample attains 319.92 °C from pure PVA of 302.90 °C. The design strategy of PVA combined 2D MXene nanosheet and DOPO derivatives construct oriented porous composite aerogel paves the way for the fabrication and customization of ultralight flame-retardant polymer composites, which can be expected to be applied in construction and reduce fire risk.</p></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"229 ","pages":"Article 111006"},"PeriodicalIF":6.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238378","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":"A new strategy for constructing ZIF-67@PBA core-shell 3D cross-heterostructures for improving fire safety of TPU at ultra-low addition amount","authors":"Yiwei Geng ,&nbsp;Rongjia Li ,&nbsp;Ran Song ,&nbsp;Zexuan Zhao ,&nbsp;Xinliang Liu ,&nbsp;Lei Liu ,&nbsp;Lei Yang ,&nbsp;Baojun Li ,&nbsp;Xilei Chen ,&nbsp;Chuanmei Jiao","doi":"10.1016/j.polymdegradstab.2024.111004","DOIUrl":"10.1016/j.polymdegradstab.2024.111004","url":null,"abstract":"<div><p>Thermoplastic polyurethane (TPU) has an extensive application in many different industries. However, serious fire hazards and smoke toxicity have been the main reason limiting its wide application. Therefore, it is necessary and urgent to perform flame retardant and smoke suppression treatment for TPU. In recent years, metal-organic framework compounds (MOFs) have very promising application prospects in the fields of flame-retardant polymer composites. However, there is a problem of low flame-retardant efficiency for the original MOFs alone in polymer composites. It is reported the multi-level and multi-structured flame-retardant system has better flame-retardant efficiency than the traditional structures. So, the dual MOF core-shell heterostructure may have more effective heat reduction and smoke suppression than any single component. In this paper, a core-shell 3D cross-heterostructures nanohybrid (ZIF-67H@PBA) was prepared using ZIF-67H as the host MOF and Prussian blue nanocubes (PBA) as the guest MOF. It has been found that TPU/ZIF-67H@PBA composites with ultra-low additions have excellent fire safety. Compared with those of pure TPU, the peak heat release rate (PHRR), total smoke release (TSP), and smoke factor (SF) of the samples with 0.5wt% ZIF-67H@PBA were reduced by 33.6 %, 47 %, and 61 %, respectively. At the same time, a cone calorimeter (CCT), a homemade soot sampling device and a gas chromatography-mass spectrometry (GC–MS) coupling with each other were constructed and used to demonstrate the most realistic effects of flame retardants in terms of smoke suppression and toxicity reduction. This work provides a new strategy to design TPU flame retardants.</p></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"229 ","pages":"Article 111004"},"PeriodicalIF":6.3,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238376","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}