Polymer Degradation and Stability最新文献

{"title":"Molecular dynamics and finite element analysis of partial discharge mechanisms in polyimide under high-frequency electric stress","authors":"Bilal Iqbal Ayubi,&nbsp;Li Zhang,&nbsp;Guan Wang,&nbsp;Yiwei Wang,&nbsp;Shengrui Zhou","doi":"10.1016/j.polymdegradstab.2025.111252","DOIUrl":"10.1016/j.polymdegradstab.2025.111252","url":null,"abstract":"<div><div>High-frequency power transformers (HFPTs) are critical components of solid-state transformers (SSTs), enabling voltage conversion and electrical isolation in advanced power distribution systems. However, the insulation systems of HFPTs face significant challenges due to high-frequency electrical stress and partial discharges (PD). This study investigates the failure mechanisms of polyimide (PI) insulation under high-frequency electrothermal stress through a combination of experimental analysis and numerical simulations. A high-frequency partial discharge test platform was utilized to evaluate PD behavior in PI films under sinusoidal voltages at various frequencies. Experimental results revealed that increasing frequency reduced the insulation breakdown time and discharge counts while intensifying discharge amplitude and accelerating material degradation. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the successful synthesis of PI films and demonstrated a reduction in key chemical bonds following degradation. ReaxFF molecular dynamics simulations provided insights into the degradation mechanisms, identifying CO as the most abundant degradation product, followed by H₂, H₂O, CN, and acetylene (C₂H₂). Finite element simulations, based on a one-dimensional non-equilibrium plasma model, elucidated the spatiotemporal evolution of electric fields, electron density, electron temperature, space charge, and PD currents. The results demonstrated a direct correlation between higher frequencies and intensified PD activity, including stronger electric fields and increased electron energy. This comprehensive study bridges experimental observations with simulation results, advancing the understanding of insulation failure mechanisms in HFPTs under high-frequency stress.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"234 ","pages":"Article 111252"},"PeriodicalIF":6.3,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395713","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":"Synergic effect between α-zirconium phosphate nanohybrid and aluminum hypophosphite to achieve eco-friendly high fire safety and mechanical strength","authors":"Zhenhua Wang ,&nbsp;Yifang Hua ,&nbsp;Weiwen Gu ,&nbsp;Hongfei Li ,&nbsp;Xiaoyu Gu ,&nbsp;Jun Sun ,&nbsp;Sheng Zhang","doi":"10.1016/j.polymdegradstab.2024.111120","DOIUrl":"10.1016/j.polymdegradstab.2024.111120","url":null,"abstract":"<div><div>The simple addition of conventional flame retardants has made it difficult to achieve a balance between fire safety, smoke suppression, smoke toxicity and mechanical properties in flame-retardant polyurethanes. How to effectively integrate flame-retardant elements to synergize with traditional flame retardants while keeping the preparation process simple remains a major research challenge. Here, an in-situ supramolecular self-assembly organic-inorganic hybrid strategy was proposed. α-ZrP as an assembly aid, phosphorus-nitrogen integrated two-dimensional nanosheets (ZAMP) was prepared to work synergistically with aluminum hypophosphite (AHP), enhancing fire safety, smoke suppression, and anti-dripping properties of thermoplastic polyurethane (TPU). Due to the radical scavenging, gas dilution and physical barrier effects, and catalytic carbonization promoted by the 2D hybrid nanosheets, the flame-retardant polyurethane achieves a V0 rating in UL-94, self-extinguishes quickly without melt dripping, and exhibits a high limiting oxygen index (27.5 %), along with reduced peak heat release rate (74.8 %) and peak smoke production rate (54.55 %). Compared to single AHP addition (TPU/7 %AHP), TPU/6 %AHP/1 %ZAMP shows enhanced fire safety, lower smoke toxicity and better retention of mechanical properties. This straightforward supramolecular self-assembly flame-retardant strategy, using α-ZrP as an anchoring layer, provides new insights into designing highly effective nano flame-retardant synergists with broad fire protection performance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111120"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183399","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":"Catalytic upcycling of silicone rubber by AlCl3 at low temperature","authors":"Kemeng Liu ,&nbsp;Xueying Wen ,&nbsp;Huiyue Wang ,&nbsp;Huajian Liu ,&nbsp;Lijie Liu ,&nbsp;Ran Niu ,&nbsp;Tao Tang ,&nbsp;Nan Yao ,&nbsp;Ruikun Pan ,&nbsp;Jiang Gong","doi":"10.1016/j.polymdegradstab.2024.111117","DOIUrl":"10.1016/j.polymdegradstab.2024.111117","url":null,"abstract":"<div><div>Chemical recycling of silicone rubber (SR) waste into valuable products has aroused ever-increasing attention; however, the development of a green, efficient degradation strategy for silicone rubber remains challenging. In this work, we report the catalytic upcycling of silicone rubber by AlCl₃ to produce SiO₂ under atmospheric environment. The optimized AlCl₃/SR mass ratio, reaction temperature and time are 0.75, 280 ℃ and 120 min, respectively. The maximum yield of SiO₂ is 96 %. The as-prepared SiO₂ displays irregular spherical agglomerates with a particle size of 20–30 nm and bears rich micropores/mesopores/macropores. The result of variable-temperature Fourier-transform infrared spectroscopy proves that AlCl₃ promotes the fracture of Si-O in SR during heating. According to density functional theory, the addition of AlCl₃ leads to a decrease in the bond dissociation energy of Si-O and Si-C. The strategy achieves the green, efficient catalytic degradation of silicone rubber waste.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111117"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182521","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 role of diffusion in the hydrolytic degradation of poly(lactic-co-glycolic acid): A molecular perspective","authors":"Qiang Zhang ,&nbsp;Matthias Heuchel ,&nbsp;Andreas F. Thüneman ,&nbsp;Rainhard Machatschek","doi":"10.1016/j.polymdegradstab.2024.111119","DOIUrl":"10.1016/j.polymdegradstab.2024.111119","url":null,"abstract":"<div><div>This research emphasizes the importance of internal surface erosion as a key factor in the hydrolytic degradation of PLGA (poly(D,L-lactic-co-glycolic acid)) providing an alternative view of the established surface and bulk erosion degradation modes. Using molecular dynamics (MD) simulations, this study reveals the role of water and oligomer diffusion during the degradation of PLGA and highlights the importance of water channels formed as the overall water content increases. We found that these continuous water channels play a crucial role in accelerating the transport of water and the release of degradation products from the polymer matrix, as the diffusion coefficients of water and small oligomers exhibit significant differences spanning 2 to 3 orders of magnitude between the water and polymer phases. Water follows a different diffusion mechanism than polymer fragments. The diffusion rate of the fragments up to a size of octamers was found to be size-dependent and reasonably well approximated by a 1/<em>N</em> behavior, in line with the Rouse model.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111119"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182524","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":"Enhanced UV stability of polyimide based on pendent ortho-hydroxybenzophenone UV-absorbing groups","authors":"Jialin Zhang ,&nbsp;Jie Dong ,&nbsp;Xin Zhao ,&nbsp;Xiuting Li ,&nbsp;Qingsong Xu ,&nbsp;Qinghua Zhang","doi":"10.1016/j.polymdegradstab.2024.111165","DOIUrl":"10.1016/j.polymdegradstab.2024.111165","url":null,"abstract":"<div><div>With the trend toward lighter and longer-lasting spacecraft operating in harsh environments, developing advanced high-performance polymer materials with adequate photostability has become an urgent issue. Here, a strategy is proposed to introduce UV-absorbing units as pendent side groups into polyimide (PI) backbone to develop intrinsic PI materials through molecular structure design. Compared with direct incorporation into polymer backbone, this method has a minimal impact on diamine reactivity, enabling the preparation of PI with high molecular weights, and more effectively inhibiting initial UV degradation. The addition of only 5 % of functional monomers for copolymerization can significantly enhance UV resistance while maintaining excellent mechanical and thermal properties. Furthermore, for PI fibers, combining chemical structure with the regulation of the aggregate structure during fiber spinning and heat-drawing process can produce high-performance PI fibers with superior overall properties. Unlike the conventional addition of inorganic nanoparticles or organic UV absorbers, this work aims to establish the relationship between chemical structure, material properties, and UV degradation mechanism. It provides a novel approach from the perspective of molecular structure design for advanced high-performance polymers that require complex processing and stringent performance demands, including long-term UV resistance and mechanical performance.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111165"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182809","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":"Halopseudomonas sp. MFKK-1: A marine-derived bacterium capable of degrading poly(butylene succinate-co-adipate), poly(ε-caprolactone), and poly(butylene adipate-co-terephthalate) in marine ecosystems","authors":"Phouvilay Soulenthone ,&nbsp;Miwa Suzuki ,&nbsp;Yuya Tachibana ,&nbsp;Maya Furukori ,&nbsp;Taijiro Saito ,&nbsp;Rina Kawamura ,&nbsp;Paul Olusegun Bankole ,&nbsp;Ken-ichi Kasuya","doi":"10.1016/j.polymdegradstab.2024.111161","DOIUrl":"10.1016/j.polymdegradstab.2024.111161","url":null,"abstract":"<div><div>Aliphatic and aliphatic-aromatic polyesters are potentially biodegradable polymers that have garnered attention as promising solutions to plastic waste menace, particularly in marine environments. Among these, poly(butylene succinate-<em>co</em>-adipate) (PBSA), which has polyethylene-like properties, is used as biodegradable packaging and mulch film. However, the slow degradation of PBSA in marine environments presents a challenge. We isolated a polyester-degrading bacterium, MFKK-1, from seawater collected from a quay and investigated its PBSA degradation potential in the marine environment. The isolate, identified as a member of the genus <em>Halopseudomonas,</em> demonstrated PBSA degradation potential at the salinity levels of seawater. In addition to PBSA, the strain could degrade poly(<em>ε</em>-caprolactone) (PCL) and the aliphatic-aromatic polyester poly(butylene adipate-<em>co</em>-terephthalate) (PBAT). The strain used 1,4-butanediol and adipate, monomeric components of PBSA, as carbon sources for growth. Moreover, the gene <em>aph_Hsp</em>, responsible for the degradation of polyesters, was heterologously expressed in <em>Escherichia coli</em>. The purified recombinant APH<em>_Hsp</em> was characterized. This enzyme belongs to the α/β hydrolase family, with a catalytic triad composed of Ser₁₇₁, Asp₂₁₇, and His₂₄₉. It is a mesophilic enzyme that has shown the ability to degrade PBSA, PCL, and PBAT films in buffer supplemented with 0.5 M NaCl, a salinity comparable to that of seawater. Furthermore, the enzyme degraded amorphous poly(ethylene terephthalate) under 0.5 M NaCl conditions. The findings of this study enhance our knowledge of the microbial degradation of polyesters in marine environments, potentially supporting the sustainable application of biodegradable materials in ocean ecosystems.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111161"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183397","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":"Multiple synergistic effects of copper salicylaldehyde-modified P-N inorganic-organic hybrid in enhancing flame retardancy, smoke suppression, and anti-dripping properties of TPU","authors":"Gaoyuan Li ,&nbsp;Haopeng Zhang ,&nbsp;Jirui Qu ,&nbsp;Biyu Huang ,&nbsp;Hongbo Zhao ,&nbsp;ShaoFeng Wang ,&nbsp;Xilei Chen ,&nbsp;Chuanmei Jiao","doi":"10.1016/j.polymdegradstab.2024.111136","DOIUrl":"10.1016/j.polymdegradstab.2024.111136","url":null,"abstract":"<div><div>In recent years, significant progress has been made in the research of flame-retardant thermoplastic polyurethane (TPU) elastomers. However, challenges persist in balancing the enhancement of flame retardancy, smoke suppression, and anti-dripping properties with the preservation of mechanical properties. To address this challenge, a copper salicylaldehyde-modified P-N inorganic-organic hybrid flame retardant (P-N@CuSA) has been prepared and used to improve both the fire safety and mechanical property of TPU in this work. The experimental results showed that the incorporation of 4 wt% P-N@CuSA leads to a 65.1 % reduction in peak heat release rate, a 31.9 % decline in total smoke production, and a 31.3 % decrease in total carbon monoxide production for TPU/4 %P-N@CuSA compared with pure TPU (TPU/0). Notably, 4 wt% P-N@CuSA endowed TPU with a UL-94 V-0 rating without melt dripping. Further analysis of the thermal degradation behavior of TPU composites, combined with an examination of the char residue structure after the cone calorimeter test (CCT), reveals that P-N@CuSA acts through both gas-phase and condensed-phase flame retardant mechanisms during combustion. It subtly alters the thermal cracking trajectory of TPU composites and promotes the formation of a high-quality char residue layer, which serves as a formidable barrier against heat transfer and gas emission. As a result, this innovative approach significantly enhances the overall fire safety performance of TPU materials. This work presents a new strategy for the chemical modification of phosphorus-nitrogen-based flame retardants (P-N FRs) by metal chelates, offering a fresh perspective for the development of fire-safe composites.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111136"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181550","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":"Chemical aging and degradation of stereolithographic 3D-printed material: Effect of printing and post-curing parameters","authors":"Md Shahjahan Mahmud ,&nbsp;Antonio Delgadillo ,&nbsp;Juan E.M. Urbay ,&nbsp;Md Sahid Hassan ,&nbsp;Saqlain Zaman ,&nbsp;Dominic Dieguez ,&nbsp;Diana Fontes ,&nbsp;Diana Leyva ,&nbsp;Joshua Dantzler ,&nbsp;Alexis Lopez ,&nbsp;Sarah Nathan Joyce ,&nbsp;David A. Roberson ,&nbsp;Katja Michael ,&nbsp;Yirong Lin ,&nbsp;Alexandria N. Marchi ,&nbsp;Brian Elias Schuster","doi":"10.1016/j.polymdegradstab.2024.111151","DOIUrl":"10.1016/j.polymdegradstab.2024.111151","url":null,"abstract":"<div><div>Stereolithography (SLA) 3D printing materials have gained significant interest due to their potential applications in various industries, including material processing, microfluidic devices, medical devices, and lightweight engineering. However, their mechanical and chemical properties can be influenced by printing, post-processing, and aging. This research investigated the mechanical performance of a methacrylate-based material produced under different printing and post-curing conditions and explored its chemical degradation. The test specimens were additively manufactured with different print orientations (POs) and layer heights (LHs), followed by post-curing at various temperatures and durations, and then artificially aged in 6 M HNO₃. Tensile tests, nano-indentation, FTIR, and microscopic analyses were conducted before and after aging. The outcomes revealed that PO had limited influence on mechanical performance, except for the 0˚ PO, which showed inferior performances compared to 45˚ and 90˚ samples. Conversely, post-curing parameters, particularly curing temperature, significantly impacted final properties. FTIR analysis confirmed that post-curing increases the degree of conversion (DOC), thus resulting in enhanced ultimate stress and modulus. However, a higher DOC was associated with more brittleness. Regarding chemical degradation, the PO and curing temperature were the most influential factors, with the 0˚ PO showing reduced swelling and degradation; and higher curing temperatures resulting in lower degradation. On the other hand, LH showed mixed effects on mechanical performance and degradation. These findings address critical gaps in current research on 3D-printed polymer performance and degradation, offering insights into the application of additively manufactured polymer materials in various industrial settings.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111151"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183392","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":"Morphological effect on high-voltage insulation properties in polypropylene/elastomer binary blends: An experimental and simulation study","authors":"Oh-Uk Lee ,&nbsp;Taehoon Kwon ,&nbsp;Nazirul Mubin bin Normansah ,&nbsp;Do-Kyun Kim ,&nbsp;Yong Jin Kwon ,&nbsp;Min Ji Kim ,&nbsp;Dae Ho Lee ,&nbsp;Ik Su Kwon ,&nbsp;Youngho Eom ,&nbsp;Hana Kim ,&nbsp;Masahiro Kozako ,&nbsp;Minhee Kim ,&nbsp;Seunggun Yu","doi":"10.1016/j.polymdegradstab.2025.111223","DOIUrl":"10.1016/j.polymdegradstab.2025.111223","url":null,"abstract":"<div><div>Polypropylene (PP)/elastomer blends have been widely studied as promising insulation materials for high-voltage (HV) power cables. Among various factors, the size of elastomer domains critically influences their electrical insulation performance, such as resistivity and breakdown strength (BDS). However, this relationship remains poorly understood. This study investigates the effect of the polyolefin elastomer (POE) domain size on the high-voltage insulation properties of the PP/POE blend. The binary blends were prepared through melt-blending of the PP and POE at the different mixing temperature from 185 to 235 °C. As an increase of the mixing temperature, the size of dispersed POE domain was linearly increased due to the viscosity differences between the PP and POE. In addition, the tensile strength, elongation, volume resistivity, and DC breakdown strength were decreased with mixing temperature, which were thus correlated with the POE domain size. The BDS values derived from simulations were consistent with those calculated via the Power law equation, showing a decline in BDS with increasing mixing temperature. Analysis of electric field distribution and space charge accumulation indicated that smaller POE domains more effectively mitigate electric field imbalances, delaying BD compared to larger domains. This study highlights the significant role of morphology in determining the insulation performance of polymer blends, providing valuable insights for the design of HV insulation materials.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"234 ","pages":"Article 111223"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350854","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":"Surface photooxidation of polypropylene-based photovoltaic backsheets: A comprehensive spectroscopic investigation","authors":"Karissa L. Jensen ,&nbsp;Ashlee Aiello ,&nbsp;Stefan Mitterhofer ,&nbsp;Chiara Barretta ,&nbsp;Gernot Oreski ,&nbsp;Christopher M. Stafford ,&nbsp;Xiaohong Gu","doi":"10.1016/j.polymdegradstab.2024.111132","DOIUrl":"10.1016/j.polymdegradstab.2024.111132","url":null,"abstract":"<div><div>The prospect of cost reduction, enhanced performance, and improved sustainability has been driving innovation in the development of new backsheet materials for photovoltaic (PV) modules. Among the materials of interest, polypropylene (PP) has emerged as a promising alternative to fluoropolymer backsheets. As backsheets serve as a barrier providing electrical insulation and protection for the sensitive electrical components of PV modules, comprehensive understanding of the durability of PP-based backsheets is essential to ensure module reliability in the field.</div><div>In this study, free-standing coextruded PP backsheets were subjected to artificial weathering to elucidate the degradation behavior. The UV exposure was performed on the NIST Simulated Photodegradation via High Energy Radiant Exposure (SPHERE) under three environmental conditions: 75 °C and 50 % relative humidity (RH), 75 °C and 20 % RH, and 65 °C and 20 % RH. The total UV dose (295 nm to 400 nm) for each film was ≈1710 MJ/m², or ≈50 years in Arizona, assuming 10 % albedo. Chemical, optical, and physical changes were monitored throughout exposure. Peak-resolving analysis was applied to attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra to obtain functional group concentrations with respect to exposure. The greatest chemical and physical changes are seen after initial exposure (100 MJ/m² to 220 MJ/m²), followed by a saturation point. Spectroscopic results indicate minor accumulation of oxidation products and additive migration. Raman spectroscopy showed a slight increase in crystallinity of the surface layers of the backsheets. Mechanical testing revealed low cracking propensity, with shallow cracks occurring under high strains.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"232 ","pages":"Article 111132"},"PeriodicalIF":6.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181544","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}