Polymer Degradation and Stability最新文献

{"title":"Alcohol degradation of anhydride-cured epoxy resin insulations and the properties of recycled materials","authors":"Xu Zhang, Yiran Hu, Guoli Wang, Chao Gao, Jiahe Yu, Xiaoxing Zhang, Yunjian Wu","doi":"10.1016/j.polymdegradstab.2024.111134","DOIUrl":"https://doi.org/10.1016/j.polymdegradstab.2024.111134","url":null,"abstract":"Epoxy resins are widely used as electrical insulation materials due to their excellent properties. However, the three-dimensional network structure of epoxy resin makes it difficult to be degraded and recycled, and incineration or landfill will cause environmental pollution as well as waste of resources. In order to study the degradation technology of epoxy insulating materials (EIM) under mild conditions, the degradation of EIM was achieved under mild conditions using K₃PO₄ as a catalyst in ethylene glycol at 120°C for 3h. Degradation products of epoxy resin insulation materials (DEM) were used to partially replace bisphenol A diglycidyl ether (DGEBA) in the preparation of recycled epoxy resin insulation materials (RIM). The results showed that RIM could maintain good insulating properties when the DEM content was lower than 38.4 wt.%, the tensile strength and T_g were also held up will when the DEM content was 22wt.%. This study provides new ideas and methods for the recycling of epoxy resin insulating materials, which can help the resourceful reuse of epoxy cast electrical equipment after decommissioning.","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"21 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823426","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":"Thermal oxidative aging behavior and lifetime prediction of fluoroether rubber","authors":"Haonan Shi ,&nbsp;Yongjian Zhao ,&nbsp;Yupeng Su ,&nbsp;Song Hu ,&nbsp;Yumin Shi ,&nbsp;Xinyan Shi","doi":"10.1016/j.polymdegradstab.2024.111106","DOIUrl":"10.1016/j.polymdegradstab.2024.111106","url":null,"abstract":"<div><div>Fluoroether rubber's performance offers extensive application potential in harsh conditions. This article investigates the thermal-oxidative aging behavior and life prediction of fluoroether rubber using methods such as Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric Analyzer (TGA), Differential Scanning Calorimeter (DSC) and Compression Set. Results indicate that with prolonged aging, fluoroether rubber exhibits decreased heat resistance, damaged TAIC crosslink structures, and weakened characteristic peak intensities of main chains and side groups, leading to changes in rubber structure. Throughout the aging process, hardness, physical crosslink density, glass transition temperature, and compressive stress gradually increase, while mechanical properties decline. Using compression set as an indicator, service life at various temperatures was predicted, providing theoretical guidance for improving the reliability of fluoroether rubber seals and expanding their engineering applications.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111106"},"PeriodicalIF":6.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757605","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":"Influence of surface chemical modifications on enhancing the aging behavior of capacitor biaxially-oriented polypropylene thin film","authors":"Haider M. Umran ,&nbsp;Hasan F. Alesary ,&nbsp;Hani K. Ismail ,&nbsp;Feipeng Wang ,&nbsp;Stephen Barton","doi":"10.1016/j.polymdegradstab.2024.111105","DOIUrl":"10.1016/j.polymdegradstab.2024.111105","url":null,"abstract":"<div><div>Modern power electronic systems require appropriate metallized polypropylene capacitors (MPCs) to operate in harsh environments. Due to their limited operating capabilities, commercial biaxially-oriented polypropylene (BOPP) films—the primary component of MPCs—are susceptible to degradation in high electric fields and at high temperatures. In order to enhance the aging behavior of BOPP, this work proposes one-sided phosphorylation at optimum and excessive acid concentrations of 8 % and 15 % for 24 hours at a [high] temperature of 60 °C. The proposed surface modifications' success in enhancing the aging behaviors of BOPP is confirmed by DC electrothermal aging. Field emission scanning electron microscopy (FE-SEM) analysis reveals changes in surface morphology resulting from phosphorylation. The changes in crystal structure of the original and phosphorylated samples are evaluated using X-ray diffraction (XRD). The average crystallite size, dislocation density, and microstrain during aging are also characterized using the Williamson-Hall (W-H) analysis method. Fourier transform infrared (FTIR) spectroscopy is used to identify changes in the chemical composition and functional groups resulting from phosphorylation and aging, while X-ray photoelectron spectroscopy (XPS) is used to analyze changes in the surface chemical elements of the original, phosphorylated, and aged samples. The charge-thermally stimulated discharge (C-TSD) technique and broadband dielectric spectroscopy (BDS) are used to verify the electrical performance. Mechanical properties, including thermal stability, are measured using the dynamic mechanical analysis (DMA) technique. The results indicated that the optimized phosphorylation improved the BOPP film's electrical and mechanical properties. As a result, the surface charge stability was found to increase under thermally stimulated discharge by 74 % and the dielectric constant by 2 %, while the dielectric losses decreased by 20.2 %. Under aging, for the first time, the dielectric constant was found to increase by 4.8 %, while dielectric losses decreased by 8.9 %. In return, deformation resistance, ductility, and lower energy dissipation demonstrated enhanced mechanical performance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"231 ","pages":"Article 111105"},"PeriodicalIF":6.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743018","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":"Efficient degradation and recycling of carbon fiber reinforced epoxy composite wastes under mild conditions by constructing dual dynamic covalent networks","authors":"Cong Yang ,&nbsp;Xinnian Xia ,&nbsp;Yale Xiao ,&nbsp;Guoqing Wei ,&nbsp;Yanbing Lu","doi":"10.1016/j.polymdegradstab.2024.111102","DOIUrl":"10.1016/j.polymdegradstab.2024.111102","url":null,"abstract":"<div><div>The recycling of high-value cores from epoxy composite wastes is critical for environmental protection and sustainable development. However, the efficient degradation of epoxy resin under mild conditions remains a significant challenge due to its stable 3D crosslinked network structure. Herein, we propose an innovative strategy utilizing dual dynamic covalent bonds to achieve efficient, safe, and controlled degradation of epoxy resins in solvents. Specifically, a series of epoxy resins D_xBV_y/NMA containing dual dynamic covalent bonds (imine and ester bonds) were prepared by combining the bio-based epoxy monomer BV-EP, which contains imine bonds, with the commercial epoxy monomer DGEBA, followed by curing with nadic methyl anhydride (NMA). The results demonstrate that the incorporation of BV-EP maintains excellent thermomechanical properties and thermal stability in D_xBV_y/NMA systems. Remarkably, D₅BV₅/NMA achieved 100 % degradation in aminoethanol at 160 °C within just 25 min, indicating an extraordinarily high degradation efficiency. The degradation mechanism was elucidated using FTIR and ¹H NMR, revealing that both imine and ester bonds in the crosslinked structure can undergo exchange reactions with amino groups in aminoethanol. Importantly, the carbon fiber reinforced epoxy composite CF-D₅BV₅/NMA was also efficiently degraded in this system, allowing for recycling through a straightforward post-processing step, yielding virtually non-destructive carbon fibers (CF) and high-purity monomer 9,9-bis(4-aminophenyl)fluorene (BAPF). This work introduces a novel approach for the efficient and lossless recycling of CF from the carbon fiber reinforced epoxy composite wastes, thereby contributing to the sustainable development of the epoxy resin field.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"231 ","pages":"Article 111102"},"PeriodicalIF":6.3,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743123","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":"Polymer-based phosphoramidite flame retardant for TPU: Enhanced fire resistance with preserved transparency and mechanical properties","authors":"Haoran Shi ,&nbsp;Yajun Chen ,&nbsp;Fenghao Hao ,&nbsp;Lijun Qian","doi":"10.1016/j.polymdegradstab.2024.111103","DOIUrl":"10.1016/j.polymdegradstab.2024.111103","url":null,"abstract":"<div><div>In this work, a polymeric flame retardant (POP) containing a phosphoramidite bond was synthesized from piperazine and phenyl dichlorophosphate. The chemical structure of POP was confirmed using FTIR, TGA, DSC, ¹H NMR, ³¹P NMR, ¹³C NMR and PY-GC–MS. Adding POP to TPU significantly improved its flame retardancy while maintaining its mechanical properties and transparency. Only 3 wt% of POP reduced the peak heat release rate (PHRR) of the TPU composite by 50.1 %. With increasing POP content, the PHRR and total heat release (THR) of the TPU composites decreased further, and the char residue increased. At 15 % POP, the THR and PHRR of TPU decreased by 40.7 % and 60.2 %, with char residue reaching 21.6 %. Moreover, when the amount of POP was 30 %, the TPU composite reached a LOI value of 29.2 %, passing UL 94 V-0 level. The improved flame retardancy resulted from the prior concentrated emission of CO₂ in the gaseous phase and the creation of denser, more graphitized char residue within the condensed phase. Additionally, the excellent compatibility between POP and TPU ensured minimal impact on the mechanical properties and transparency. The tensile strength, elongation at break, and transmittance of TPU/15 % POP were 40.2 MPa, 525 %, and 81.5 %, nearly matching the performance of pure TPU.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111103"},"PeriodicalIF":6.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748785","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":"Mechanoluminescence driven by oxidation reactions in epoxy resins","authors":"Baptiste Robbiani,&nbsp;Jean-Louis Augé,&nbsp;Gilbert Teyssèdre","doi":"10.1016/j.polymdegradstab.2024.111101","DOIUrl":"10.1016/j.polymdegradstab.2024.111101","url":null,"abstract":"<div><div>The luminescence of two imidazole or anhydride cured epoxy resins has been investigated under the combined effect of mechanical stress and temperature using a special experimental setup developed for this purpose. Rupture and cyclic mechanical tests have been conducted in air and in nitrogen between room temperature and 110 °C. Luminescence was acquired through both temporal and spectral acquisitions. Light emission is observed only in air, and fits a Zhurkov model of bond scission. Spectral measurements show that adding a mechanical component to a thermal stress does not excite new molecular groups, indicating that degradation mechanisms under thermal stress or both thermal and mechanical stresses could be similar. A simple two-step model is proposed to describe luminescence as a combination of bond scission and light decay.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111101"},"PeriodicalIF":6.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748784","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":"Innovative development of green nitrogen-phosphorus-based flame retardant for enhancing fire safety of cotton fabrics","authors":"Fengfeng Feng ,&nbsp;Wei Wang ,&nbsp;Yuxin Peng ,&nbsp;Huan Liu ,&nbsp;Jie Zhang ,&nbsp;Mei Zhang ,&nbsp;Weijie Wang ,&nbsp;Junzhi Ma","doi":"10.1016/j.polymdegradstab.2024.111089","DOIUrl":"10.1016/j.polymdegradstab.2024.111089","url":null,"abstract":"<div><div>This study presents the synthesis and application of a novel green nitrogen-phosphorus flame retardant, ammonium salt of neopentyl glycol phosphate acid (ASNGPA), for cotton fabrics to enhance their fire resistance. ASNGPA was developed utilizing neopentyl glycol, phosphoric acid, and urea as the primary raw materials, which resulted in the formation of target product containing the active group -O-P(=<em>O</em>) -(ONH₄⁺)₂. Subsequently, fire-retardant fabric could be achieved by grafting ASNGPA onto the fabrics through forming -O-P(=<em>O</em>)-O-C- bonds in dipping and high-temperature process. Structural characterization by nuclear magnetism resonance (NMR), Fourier transform infrared spectroscopy test (FT-IR), and X-ray diffraction (XRD), as well as scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS), confirmed the chemical structure and elemental composition of ASNGPA and ASNGPA-treated fabrics. Thermal stability tests indicated the improved thermal behavior, delayed onset of decomposition and reduced weight loss rates of samples during heating. The comprehensive assessment of fabric's flame retardancy through vertical flame vest, limiting oxygen index (LOI) measurements, and cone calorimetry has significantly demonstrated the enhanced fire resistance properties. The LOI values of the samples with 10 %, 20 % and 30 % concentration are all above 40 % while ASNGPA-treated fabrics exhibited reduced heat and smoke release velocities when compared to their untreated cotton counterparts. Furthermore, ASNGPA-treated fabrics preserved their satisfactory durability even after numerous washing cycles. The eco-friendliness of ASNGPA lies in its formaldehyde-free synthesis process and the absence of harmful halogenated gases produced during combustion, despite slight modifications in its mechanical properties. The research on this new nitrogen-phosphorus flame retardants would enhance the flame retardancy of materials. By integrating the advantages of nitrogen and phosphorus, it could reduce fire risks while mitigating environmental pollution, aligning with the trend of green development.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"231 ","pages":"Article 111089"},"PeriodicalIF":6.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743017","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":"Accurate measurement of the localized degree of grafting using thermogravimetric analysis","authors":"Masaaki Omichi ,&nbsp;Hiroyuki Hoshina ,&nbsp;Hidenobu Morishima ,&nbsp;Kunihiro Ohshima ,&nbsp;Noriaki Seko","doi":"10.1016/j.polymdegradstab.2024.111087","DOIUrl":"10.1016/j.polymdegradstab.2024.111087","url":null,"abstract":"<div><div>A method for accurately measuring the degree of grafting (DG) in a small area of several tens of square millimeters to several tens of square centimeters is proposed. This method employs thermogravimetric analysis to take advantage of the similarity in pyrolysis behavior of grafted materials with similar DGs. A pre-irradiation method is used for graft polymerization with an acrylic acid monomer to a cotton fibers substrate, and the proposed method is used to quantify the DG of the grafted material. Cryo-milling is used to homogenize the grafted material, and reference samples with known DGs (DG: 1.9 %–107.0 %) are prepared. Subsequently, localized DG is determined by measuring the pyrolysis behavior and comparing it to that of the reference samples. In experiments, the proposed method accurately predicts the DGs of test samples with a difference of &lt;1.0 % from gravimetric measurements, especially at low DGs of 0 %–40.0 %. The proposed method can also detect the DG distribution of a cotton fiber substrate with a thickness of &lt;1 mm. The proposed method is expected to be useful for detecting heterogeneous graft reactions and improving quality control of grafted materials in industrial applications.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"231 ","pages":"Article 111087"},"PeriodicalIF":6.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723120","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":"A double encapsulation strategy for enhancing the comprehensive performance of PO cable materials","authors":"Fuhao Yu,&nbsp;Pengfei Jia,&nbsp;Songyang Yu,&nbsp;Bibo Wang,&nbsp;Lei Song,&nbsp;Yuan Hu","doi":"10.1016/j.polymdegradstab.2024.111096","DOIUrl":"10.1016/j.polymdegradstab.2024.111096","url":null,"abstract":"<div><div>Traditional polyolefin (PO) flame-retardant cable materials face challenges such as low flame-retardant efficiency and poor mechanical properties, particularly when environmentally friendly magnesium hydroxide (MH) is added. Herein, this work presents a novel approach to enhancing flame-retardant PO cable materials through a dual encapsulation strategy for MH. The double-encapsulated MH (HZM) was synthesized by depositing zinc hydroxy stannate, followed by microencapsulation using supramolecular polyphosphazene compounds. The PO composites achieved a V-0 rating with the addition of 56 wt% HZM, whereas the PO materials received no rating with the same loading of pure MH. Combined with the dual advantage of ZHS and supramolecular layer, the peak heat release rate and total heat release of PO-HZM decreased by 71.5% and 36%, respectively. HZM also exhibited outstanding smoke suppression (total smoke, CO₂, and CO) of PO composites. Furthermore, compared to PO-MH, the mechanical properties of PO-HZM had been strengthened because of the enhanced compatibility between HZM and PO matrix. Therefore, the double encapsulation of MH offers an effective strategy for developing revolutionary PO cable materials with enhanced comprehensive performance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"231 ","pages":"Article 111096"},"PeriodicalIF":6.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743124","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":"Iminodiacetic acid enhances the mechanical and degradation properties of copolyesters by hydrogen bonding and branching","authors":"Chaochen Xu ,&nbsp;Wufeng Shen ,&nbsp;Chao Zeng ,&nbsp;Yixiao Yu ,&nbsp;Shengming Zhang ,&nbsp;Peng Ji ,&nbsp;Huaping Wang","doi":"10.1016/j.polymdegradstab.2024.111100","DOIUrl":"10.1016/j.polymdegradstab.2024.111100","url":null,"abstract":"<div><div>The development of biodegradable polyester materials is of great significance in alleviating the problem of plastic pollution. Poly(butylene terephthalate adipate) (PBAT) is a typical aliphatic-aromatic copolyester and has a capacity of several hundred thousand tons per year. However, the relatively low mechanical strength and high requirement for degradation environment of PBAT limit its application fields. To compensate for the deficiencies in mechanical and degradable properties of PBAT, this study reports a molecular chain structure design on the amorphous region using diethyl iminodiacetate (DEI). A series of poly(butylene adipate iminodiacetate terephthalate) (PBAIT) with a DEI content of 5–20 mol% were obtained. DEI contains secondary amine groups, which can be amidated with ester bonds to produce branched sites, and branched structures can be formed from 75 to 79 % of DEI during the copolymerization process. PBAIT-10 exhibit better tensile strength (23.87 MPa), tensile modulus (108.2 MPa) and hydrophilicity than those of PBAT. In addition, PBAIT-10 also shows very high toughness, with an elongation at break of over 1000 %. PBAITs can be degraded in enzymatic or hydrolytic environments. The degradation mechanism was analyzed by ¹H NMR spectra and FTIR, and further combined with 2D-IR analysis, which reveals the rapid degradation of the BI chain segments regardless of whether or not they form branched sites. This work provides an idea to prepare copolyesters that combine good mechanical properties with degradability under mild conditions.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"231 ","pages":"Article 111100"},"PeriodicalIF":6.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743125","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}