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Onion-inspired construction of bio-based and halogen-/phosphorus-free carbon microspheres hybrids via multi-layer hierarchical structure strategy for trading off the single-component flame retardant properties of silicone rubber 以洋葱为灵感,通过多层分层结构策略构建生物基和无卤/无磷碳微球杂化物,以抵消硅橡胶的单组分阻燃性能
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-16 DOI: 10.1016/j.polymdegradstab.2025.111870
Ziyang Zhang , Xiaoyang Guo , Wen Wang , Jing He , Zaihang Zheng
Nowadays, the practical application for high-performance silicone rubber (SR) was constrained and limited by its intrinsic flammability, which would be usually solved by the incorporation of halogenated or heavily loaded phosphorus-based flame retardants. The extensive reliance on halogen-/phosphorus-based retardants would not only pose the irreversible risk to human health and ecological environment, but also raise the serious sustainability concerns about the progressive depletion of phosphate resources. Moreover, the insertion of these conventional flame retardants would inevitably compromise the mechanical properties of SR materials, which was not feasible for enhancing the application value and scopes in real life. Inspired by hierarchical structure of onion, a halogen-/phosphorus-free and bio-based flame retardant system (CMs@PDA@LDH@MM) was rationally engineered via a hierarchical assembly strategy by integrating renewable glucose-derived carbon microspheres with polydopamine (PDA), Ni-Al layered double hydroxides (LDH), and melamine-malic acid complex (MM). When the content of CMs@PDA@LDH@MM was 16 %, a limiting oxygen index (LOI) of 29.9 % and a UL-94 V-0 rating of SR composites were achieved together with substantial peak heat release rate (PkHRR) reduction of 56 % and smoke production rate (SPR) of 67 %, suggesting the excellent flame retardancy and fire safety performance. This fact was ascribed to the integration of multiple flame-retardant mechanism into a single hierarchical CMs@PDA@LDH@MM hybrid via the synergistic action between catalyzed charring and gaseous dilution/heat absorption ability. Furthermore, SR composites were endowed with the excellent resistance to flame impact and glow-wire ignition (GWFI > 960 °C). Most of all, the mechanical robustness of SR composites was significantly improved with a Young’s modulus increment of 708 % and the elongation at break of 332 %, which would thereby enable the structural self-sustainability under load-bearing condition. In a nutshell, the intrinsic limitation of conventional additive approach was addressed in simultaneously achieving the balanced flame retardancy and mechanical performance, which was expected to provide a new and clean insight for the rational design of sustainable and halogen-/phosphorus-free flame-retardants in the fields of construction and buildings, cables and wire, new energy vehicles and aerospace.
目前,高性能硅橡胶(SR)的实际应用受到其固有可燃性的制约和限制,通常通过添加卤化或重载磷系阻燃剂来解决这一问题。对卤/磷系缓凝剂的广泛依赖不仅会对人类健康和生态环境造成不可逆转的风险,而且还会引起对磷酸盐资源逐渐枯竭的严重可持续性关切。此外,这些常规阻燃剂的加入必然会影响SR材料的力学性能,这对于提高SR材料在现实生活中的应用价值和范围是不可行的。受洋葱分层结构的启发,通过分层组装策略,将可再生葡萄糖衍生的碳微球与聚多巴胺(PDA)、Ni-Al层状双氢氧化物(LDH)和三聚氰胺-苹果酸配合物(MM)相结合,合理地设计了一种无卤/无磷生物基阻燃体系(CMs@PDA@LDH@MM)。当CMs@PDA@LDH@MM含量为16%时,SR复合材料的极限氧指数(LOI)为29.9%,UL-94 V-0等级,峰值放热率(PkHRR)降低56%,产烟率(SPR)降低67%,具有优异的阻燃性和防火性能。这一事实归因于多种阻燃机理通过催化炭化和气体稀释/吸热能力之间的协同作用,整合成单一层次的CMs@PDA@LDH@MM混合物。此外,SR复合材料还具有优异的抗火焰冲击和抗灼热丝点火性能(GWFI > 960°C)。最重要的是,SR复合材料的力学鲁棒性得到了显著提高,杨氏模量增加了708%,断裂伸长率达到332%,从而使结构在承载条件下具有自持续性。简而言之,在实现阻燃性和力学性能平衡的同时,解决了传统添加剂方法的内在局限性,有望为建筑建筑、电缆电线、新能源汽车和航空航天等领域的可持续和无卤/无磷阻燃剂的合理设计提供新的清洁见解。
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引用次数: 0
Hygrothermal behavior of jute/PLA composites: assessment of hygroscopic internal stress and its impact on service life 黄麻/PLA复合材料的湿热行为:吸湿内应力的评估及其对使用寿命的影响
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111868
Ning Jiang , Guangxin Li , Yihua Xu , Yaomin Li , Chaozhong Chen
This study investigated the internal damage induced by transient hygroscopic stress in jute/PLA composites under hygrothermal conditions, and a mechanical prediction model was established based on the damage area. A finite element (FE) model, which incorporates the true microstructure of the short fiber reinforced composites, was established using X-ray computed tomography (XCT) and three-dimensional (3D) reconstruction techniques to accurately simulate water absorption and hygroscopic stress evolution behavior. The results of FE analysis of water absorption show good agreement with experimental measurements, indicating that the 3D model is crucial for accurately simulating the water diffusion process within the specimens. In the analysis, the locations of damage area were identified, and their content was quantified. The hygroscopic stress is the main cause of damage initiation in jute/PLA composites, leading to high variations in their mechanical properties and reducing long-term sustainability. Ultimately, by combining the time-temperature superposition (TTS) principle with a residual strength model for internal damage, a mechanical prediction model for plant fiber composites was established based on the damage area, providing accurate predictions of the composites’ mechanical properties. This approach offers an innovative methodology for evaluating the mechanical properties of such composites.
研究了湿热条件下黄麻/PLA复合材料在瞬态吸湿应力作用下的内部损伤,建立了基于损伤面积的力学预测模型。利用x射线计算机断层扫描(XCT)和三维重建技术,建立了包含短纤维增强复合材料真实微观结构的有限元(FE)模型,准确模拟了短纤维增强复合材料的吸水和吸湿应力演化行为。吸水率有限元分析结果与实验测量结果吻合较好,表明三维模型对于准确模拟试样内水分扩散过程至关重要。在分析中,确定了损伤区域的位置,并对其含量进行了量化。吸湿应力是黄麻/PLA复合材料损伤的主要原因,导致其机械性能的高度变化,降低了长期可持续性。最终,将时间-温度叠加(TTS)原理与内部损伤的残余强度模型相结合,建立了基于损伤面积的植物纤维复合材料力学性能预测模型,对复合材料的力学性能进行了准确预测。这种方法为评估这种复合材料的机械性能提供了一种创新的方法。
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引用次数: 0
Innovative flame resistant composite non-woven fabric from recycled ceramic and polyethylene terephthalate waste fibers 创新的阻燃复合无纺布回收陶瓷和聚对苯二甲酸乙二醇酯废纤维
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111869
Lin Weng , Xiaolin Zhang , Danting Hui , Yun Li
Rapid economic growth has led to a surge in global textile consumption, overwhelming waste management infrastructure. Most non-degradable textiles are currently disposed of by landfilling or incineration, contributing to environmental pollution. To address this problem, we efficiently recycled waste into a fireproof composite, featuring a ceramic fiber middle layer and polyethylene terephthalate (PET) fiber outer layers, using sustainable opening, carding, needle punching and hot-pressing techniques. This composite has been certified with a V-0 rating in the UL-94 flammability test, confirming its exceptional flame resistance. Infrared thermal imaging analysis further confirms its excellent thermal insulation and ablative resistance capabilities. Furthermore, an in-depth study on the composition of combustion residue char and gaseous volatiles demonstrated no significant flame hazards and revealed that gas-phase dilution combined with ceramic fiber residue char, disrupted the flame-fuel interaction to inhibit combustion. This research provides a facile and eco-friendly strategy for cost-efficient recovery of waste textiles, not only minimizing resource wastage but also producing a high-value product, thus significantly reducing environmental pollution.
快速的经济增长导致全球纺织品消费激增,使废物管理基础设施不堪重负。目前,大多数不可降解的纺织品都通过填埋或焚烧处理,造成环境污染。为了解决这个问题,我们高效地将废物回收成防火复合材料,其特点是陶瓷纤维中间层和聚对苯二甲酸乙二醇酯(PET)纤维外层,采用可持续的开孔、梳理、针刺和热压技术。这种复合材料在UL-94可燃性测试中获得了V-0等级的认证,证实了其卓越的阻燃性。红外热成像分析进一步证实了其优异的隔热和耐烧蚀能力。此外,对燃烧残渣炭和气态挥发物组成的深入研究表明,没有明显的火焰危害,并且发现气相稀释与陶瓷纤维残渣炭结合,破坏了火焰-燃料相互作用,抑制了燃烧。本研究为低成本回收废旧纺织品提供了一种便捷、环保的策略,不仅可以最大限度地减少资源浪费,还可以生产出高价值的产品,从而大大减少环境污染。
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引用次数: 0
Methods for predicting the fire behaviour of fibre reinforced thermoset composites 纤维增强热固性复合材料防火性能的预测方法
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111857
Ákos Pomázi , Gergely Magyar , Andrea Toldy
Destructive tests are typically used to evaluate the fire performance of polymers and their composites, implying high material costs and long testing times. Developing numerical models to predict flammability requires advanced mathematical expertise, IT resources, and realistic input parameters. In this study, we aimed to predict the key flammability parameters based on the chemical structure of the resin matrices and fibre content of composites, providing a potential alternative to costly experimental methods. We employed Random Forest Classifier (RFC), XGBoost algorithms, and an artificial neural network (ANN) model to predict key combustion parameters: peak heat release rate (pHRR), time to ignition (TTI), total heat release (THR) and the char residue (CR) solely based on chemical structure of the epoxy matrix and fibre content of the composite. After making the predictions, we assessed the performance of the models using consistent statistical indicators (mean absolute error (MAE), mean square error (MSE), and the determination parameter (R2)).
破坏性测试通常用于评估聚合物及其复合材料的防火性能,这意味着材料成本高,测试时间长。开发数值模型来预测可燃性需要先进的数学专业知识、IT资源和现实的输入参数。在这项研究中,我们旨在根据树脂基体的化学结构和复合材料的纤维含量预测关键的可燃性参数,为昂贵的实验方法提供潜在的替代方案。采用随机森林分类器(RFC)、XGBoost算法和人工神经网络(ANN)模型,仅根据环氧基的化学结构和复合材料的纤维含量预测关键燃烧参数:峰值放热率(pHRR)、点火时间(TTI)、总放热率(THR)和炭渣(CR)。在做出预测后,我们使用一致的统计指标(平均绝对误差(MAE)、均方误差(MSE)和确定参数(R2))评估模型的性能。
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引用次数: 0
Covalently bound self-passivating silica layer enhances polyetherimide stability in harsh space conditions 共价结合的自钝化二氧化硅层提高了聚醚酰亚胺在恶劣空间条件下的稳定性
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111861
Lidia Mezzina , Angelo Nicosia , Prospero Savoca , Maria Elisabetta Palumbo , Carlotta Scirè , Riccardo Giovanni Urso , Giuseppe Antonio Baratta , Anna Lucia Pellegrino , Laura Barone , Placido Mineo
The rapid expansion of human space exploration highlights the need for advanced materials capable of enduring the severe conditions of extraterrestrial environments. Polymeric materials, such as polyetherimide (PEI), are extensively used in aerospace applications due to their low density, mechanical versatility, and partial shielding capacity against radiation. Nevertheless, prolonged exposure to hostile factors such as galactic cosmic rays, solar energetic particles, solar wind ions, atomic oxygen, and electromagnetic radiation results in progressive structural degradation manifested as erosion, mass loss, and deterioration of mechanical, thermal, and optical properties. To mitigate these effects, inorganic protective layers, particularly metal oxides, have been investigated because of their high hardness, chemical stability, and erosion resistance. Despite these advantages, issues related to interfacial adhesion and long-term stability of such protective layers remain significant challenges.
The present study reports a novel covalent silica-based passivation approach for PEI, achieved through a multi-step chemical functionalization of the polymer surface. The process involves: i) the partial hydrolysis of imidic ring on PEI film surface, forming polyamic acid (PAA) layer; ii) chemical reduction of the carboxylic acid of PAA to benzylic alcohol groups; iii) grafting tetraethyl orthosilicate to benzyl alcohol moieties. The procedures were monitored using ATR-FT-IR, DSR-UV-Vis, contact angle, and SEM-EDX analyses.
To evaluate the shielding efficacy of the obtained system, both pristine PEI and silica-coated PEI samples were exposed to simulated fast solar ions flux.
The experimental results confirm the increased resistance to erosion of the silica shielded material compared to that of untreated PEI. Finally, to assess the applicability of the material in real-scenarios, a computer simulation was performed to estimate the energy dose for the proposed material as a function of the radius for different space orbits.
人类空间探索的迅速扩展突出了对能够承受地外恶劣环境条件的先进材料的需求。聚合物材料,如聚醚酰亚胺(PEI),由于其低密度、机械通用性和部分屏蔽辐射的能力,被广泛用于航空航天应用。然而,长期暴露在银河宇宙射线、太阳高能粒子、太阳风离子、原子氧和电磁辐射等不利因素下,会导致结构逐渐退化,表现为侵蚀、质量损失以及机械、热学和光学性能的恶化。为了减轻这些影响,无机保护层,特别是金属氧化物,由于其高硬度,化学稳定性和抗侵蚀性,已经被研究。尽管有这些优点,但与这种保护层的界面粘附和长期稳定性相关的问题仍然是重大挑战。本研究报告了一种新型的共价硅基PEI钝化方法,通过聚合物表面的多步化学功能化实现。其过程包括:i) PEI膜表面的亚胺环部分水解,形成聚酰胺酸(PAA)层;ii) PAA的羧酸化学还原为苯基醇基团;Iii)将正硅酸四乙酯接枝到苯甲醇部分。使用ATR-FT-IR, DSR-UV-Vis,接触角和SEM-EDX分析监测过程。为了评估所获得的系统的屏蔽效果,将原始PEI和二氧化硅涂层PEI样品暴露在模拟的快速太阳离子通量中。实验结果证实,与未经处理的PEI相比,二氧化硅屏蔽材料的抗侵蚀能力有所提高。最后,为了评估材料在实际场景中的适用性,进行了计算机模拟,以估计不同空间轨道上所提出材料的能量剂量作为半径的函数。
{"title":"Covalently bound self-passivating silica layer enhances polyetherimide stability in harsh space conditions","authors":"Lidia Mezzina ,&nbsp;Angelo Nicosia ,&nbsp;Prospero Savoca ,&nbsp;Maria Elisabetta Palumbo ,&nbsp;Carlotta Scirè ,&nbsp;Riccardo Giovanni Urso ,&nbsp;Giuseppe Antonio Baratta ,&nbsp;Anna Lucia Pellegrino ,&nbsp;Laura Barone ,&nbsp;Placido Mineo","doi":"10.1016/j.polymdegradstab.2025.111861","DOIUrl":"10.1016/j.polymdegradstab.2025.111861","url":null,"abstract":"<div><div>The rapid expansion of human space exploration highlights the need for advanced materials capable of enduring the severe conditions of extraterrestrial environments. Polymeric materials, such as polyetherimide (PEI), are extensively used in aerospace applications due to their low density, mechanical versatility, and partial shielding capacity against radiation. Nevertheless, prolonged exposure to hostile factors such as galactic cosmic rays, solar energetic particles, solar wind ions, atomic oxygen, and electromagnetic radiation results in progressive structural degradation manifested as erosion, mass loss, and deterioration of mechanical, thermal, and optical properties. To mitigate these effects, inorganic protective layers, particularly metal oxides, have been investigated because of their high hardness, chemical stability, and erosion resistance. Despite these advantages, issues related to interfacial adhesion and long-term stability of such protective layers remain significant challenges.</div><div>The present study reports a novel covalent silica-based passivation approach for PEI, achieved through a multi-step chemical functionalization of the polymer surface. The process involves: i) the partial hydrolysis of imidic ring on PEI film surface, forming polyamic acid (PAA) layer; ii) chemical reduction of the carboxylic acid of PAA to benzylic alcohol groups; iii) grafting tetraethyl orthosilicate to benzyl alcohol moieties. The procedures were monitored using ATR-FT-IR, DSR-UV-Vis, contact angle, and SEM-EDX analyses.</div><div>To evaluate the shielding efficacy of the obtained system, both pristine PEI and silica-coated PEI samples were exposed to simulated fast solar ions flux.</div><div>The experimental results confirm the increased resistance to erosion of the silica shielded material compared to that of untreated PEI. Finally, to assess the applicability of the material in real-scenarios, a computer simulation was performed to estimate the energy dose for the proposed material as a function of the radius for different space orbits.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"245 ","pages":"Article 111861"},"PeriodicalIF":7.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789186","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}
引用次数: 0
Moist-heat aging of phosphorylated cellulose nanofibril films: influence of phosphorus content and residual lignin 磷酸化纤维素纳米纤维膜的湿热老化:磷含量和残余木质素的影响
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111866
Ricardo Almeida , Ana Ramos , Verner Håkonsen , Thaddeus Maloney , Naceur Belgacem , José Gamelas
Cellulose nanofibril (CNF) films are promising high-performance sustainable materials, yet their aging behaviors remain poorly understood. Herein, films prepared from a low-phosphorus content CNF (0.65 mmol/g, P-CNF 1), a high-phosphorus content CNF (2.55 mmol/g, P-CNF 2), and a lignin-containing phosphorylated CNF (2.54 mmol/g, P-LCNF) were subjected to accelerated moist-heat aging (80 °C, 65 % relative humidity, up to eight days). Before aging, P-CNF 1 films exhibited higher degree of polymerization (DP) of cellulose, crystallinity and thermal stability, while P-CNF 2 and P-LCNF films showed significantly higher tensile strength and transparency. Under the used aging conditions, kinetic analysis of DP data revealed that P-CNF 1 films degraded approximately four times slower (k = 8.69×10–5 day-1) than P-CNF 2 (3.78×10–4 day-1) and P-LCNF (3.19×10–4 day-1) films. After eight days, P-CNF 1 films lost 52 % of the cellulose DP and 33 % of tensile strength, whereas P-CNF 2 and P-LCNF films showed larger reductions in the cellulose DP (72‒75 %) and tensile strength (63‒67 %). P-CNF 1 films also exhibited superior color stability with aging (color difference (ΔE)=6.9) than P-CNF 2 (ΔE=12.2) and P-LCNF (ΔE=8.3) films. Transparency remained nearly unchanged in all films, but specular gloss decreased, particularly for P-CNF 2 and P-LCNF films. FTIR and 31P NMR studies confirmed chemical changes induced by aging, while SEM imaging evidenced morphological alterations. Overall, phosphorus content governed stability against aging, while residual lignin mitigated color change without promoting further degradation. These findings highlight the need for chemical stabilization strategies, especially for highly phosphorylated (L)CNF films.
纤维素纳米纤维(CNF)薄膜是一种很有前途的高性能可持续材料,但其老化行为尚不清楚。在这里,由低磷CNF (0.65 mmol/g, P-CNF 1)、高磷CNF (2.55 mmol/g, P-CNF 2)和含木质素磷酸化CNF (2.54 mmol/g, P-LCNF)制备的膜进行加速湿热老化(80°C, 65%相对湿度,长达8天)。老化前,P-CNF 1膜具有较高的纤维素聚合度、结晶度和热稳定性,而P-CNF 2和P-LCNF膜具有较高的抗拉强度和透明度。在使用的老化条件下,DP数据的动力学分析表明,P-CNF 1膜的降解速度(k = 8.69×10-5 day-1)比P-CNF 2 (3.78×10-4 day-1)和P-LCNF (3.19×10-4 day-1)膜慢约4倍。8天后,P-CNF 1薄膜失去了52%的纤维素DP和33%的抗拉强度,而P-CNF 2和P-LCNF薄膜的纤维素DP(72 - 75%)和抗拉强度(63 - 67%)下降幅度更大。P-CNF 1薄膜也表现出比P-CNF 2 (ΔE=12.2)和P-LCNF (ΔE=8.3)薄膜更好的老化颜色稳定性(色差(ΔE)=6.9)。所有薄膜的透明度几乎保持不变,但镜面光泽度下降,特别是p - cnf2和P-LCNF薄膜。FTIR和31P NMR研究证实了老化引起的化学变化,而SEM成像证实了形态学改变。总体而言,磷含量控制了老化的稳定性,而残留的木质素减轻了颜色变化,而不促进进一步的降解。这些发现强调了化学稳定策略的必要性,特别是对于高度磷酸化(L)CNF膜。
{"title":"Moist-heat aging of phosphorylated cellulose nanofibril films: influence of phosphorus content and residual lignin","authors":"Ricardo Almeida ,&nbsp;Ana Ramos ,&nbsp;Verner Håkonsen ,&nbsp;Thaddeus Maloney ,&nbsp;Naceur Belgacem ,&nbsp;José Gamelas","doi":"10.1016/j.polymdegradstab.2025.111866","DOIUrl":"10.1016/j.polymdegradstab.2025.111866","url":null,"abstract":"<div><div>Cellulose nanofibril (CNF) films are promising high-performance sustainable materials, yet their aging behaviors remain poorly understood. Herein, films prepared from a low-phosphorus content CNF (0.65 mmol/g, P-CNF 1), a high-phosphorus content CNF (2.55 mmol/g, P-CNF 2), and a lignin-containing phosphorylated CNF (2.54 mmol/g, P-LCNF) were subjected to accelerated moist-heat aging (80 °C, 65 % relative humidity, up to eight days). Before aging, P-CNF 1 films exhibited higher degree of polymerization (DP) of cellulose, crystallinity and thermal stability, while P-CNF 2 and P-LCNF films showed significantly higher tensile strength and transparency. Under the used aging conditions, kinetic analysis of DP data revealed that P-CNF 1 films degraded approximately four times slower (<em>k</em> = 8.69×10<sup>–5</sup> day<sup>-1</sup>) than P-CNF 2 (3.78×10<sup>–4</sup> day<sup>-1</sup>) and P-LCNF (3.19×10<sup>–4</sup> day<sup>-1</sup>) films. After eight days, P-CNF 1 films lost 52 % of the cellulose DP and 33 % of tensile strength, whereas P-CNF 2 and P-LCNF films showed larger reductions in the cellulose DP (72‒75 %) and tensile strength (63‒67 %). P-CNF 1 films also exhibited superior color stability with aging (color difference (ΔE)=6.9) than P-CNF 2 (ΔE=12.2) and P-LCNF (ΔE=8.3) films. Transparency remained nearly unchanged in all films, but specular gloss decreased, particularly for P-CNF 2 and P-LCNF films. FTIR and <sup>31</sup>P NMR studies confirmed chemical changes induced by aging, while SEM imaging evidenced morphological alterations. Overall, phosphorus content governed stability against aging, while residual lignin mitigated color change without promoting further degradation. These findings highlight the need for chemical stabilization strategies, especially for highly phosphorylated (L)CNF films.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"245 ","pages":"Article 111866"},"PeriodicalIF":7.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838549","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}
引用次数: 0
Self-enhancement of LLDPE blown films achieved by tailoring microstructure evolution via circumfluent synergistic blow molding technology 通过循环协同吹塑技术实现了LLDPE吹塑膜的自增强
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111867
Zhangyue Zou , Yue Luo , Zhikun Gao, Zexiang Xie, Zhao-xia Huang, Haowei Jiang, Jin-Ping Qu
The performance of conventional polyolefin blown films relies solely on two processing parameters, draw ratio (DR) and blow-up ratio (BUR). In typical production, DR is much higher than BUR, leading to pronounced anisotropy and weak transverse direction (TD) properties. To address this issue, this work introduces a Circumfluent Synergistic Blow Molding Technology (CSBMT) that uses a counter-rotating blow molding die to generate a circumferential shear flow field (CSFF). CSFF can induce the polymer chains forming an interlaminar interwoven orientation microstructure and tailor the evolution of lamellar structure. This novel microstructure significantly enhances the film's TD properties and dramatically improves the TD/MD (Mechanical direction) balance of tensile strength, elongation at break, and thermal shrinkage. For instance, the balance of tensile strength improved from 0.90 to 1.03, and the balance of shrinkage ratio improved from 0.18 to 0.91. Furthermore, the ordered microstructure also enhances barrier properties by 17 % and aging resistance, where TD elongation after aging increased from 916 % to 1258 %. Therefore, this work provides a new pathway for the high-efficiency self-enhancement and performance balancing of blown films.
传统的聚烯烃吹制膜的性能仅取决于两个工艺参数:拉伸比(DR)和吹制比(BUR)。在典型的生产中,DR比BUR高得多,导致了明显的各向异性和较弱的横向(TD)特性。为了解决这个问题,本工作介绍了一种环流协同吹塑技术(CSBMT),该技术使用反向旋转吹塑模具产生环向剪切流场(CSFF)。CSFF可以诱导聚合物链形成层间交织取向的微观结构,调整层状结构的演化。这种新颖的微观结构显著提高了薄膜的TD性能,并显著改善了拉伸强度、断裂伸长率和热收缩率的TD/MD(机械方向)平衡。拉伸强度平衡由0.90提高到1.03,收缩率平衡由0.18提高到0.91。此外,有序的微观组织还能提高17%的阻隔性能和抗老化性能,其中时效后的TD伸长率从916%提高到1258%。因此,本工作为吹膜的高效自增强和性能平衡提供了新的途径。
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引用次数: 0
Poly(butylene terephthalate): About condensation, cyclization, degradation and elimination reactions in the solid state, and the role of smooth crystal surfaces 聚对苯二甲酸丁二酯:关于固体状态下的缩合、环化、降解和消除反应,以及光滑晶体表面的作用
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111862
Hans R. Kricheldorf , Steffen M. Weidner , Andreas Meyer
Three commercial poly(butylene terephthalate) (PBT) samples - Pocan B1300 (B13), Pocan B1600 (B16), and Addigy P 1210 (AP121) - served as the starting materials for the annealing experiments, which were conducted with and without the addition of esterification and transesterification catalysts. The catalysts used were Sn(II) 2-ethylhexanoate (SnOct₂), Zr(IV) acetylacetonate, and 4-toluene sulfonic acid (TSA). Temperatures varied between 150 and 210 °C. The PBT samples were characterized using differential scanning calorimetry (DSC), gel permeation chromatography (GPC), small-angle X-ray scattering (SAXS), and matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry. The MALDI mass spectra of all three samples differed greatly but displayed mass peaks of cycles. Similar results were produced by annealing with SnOct₂ or Zr(acac)₄, which favored the formation of even-numbered cycles within the mass range below m/z 5000, along with slow degradation. TSA favored a more intensive degradation without the formation of cycles or even with the destruction of cycles. PBT chains with two carboxylic (COOH) end groups were the most stable species under all circumstances. The origin of the extremely high melting point of AP121 (241–242 °C) can be explained by the smoothing of crystallite surfaces via transesterification. The results suggest that combining MALDI mass spectrometry and SAXS measurements provides a new way to better understand the solid-state chemistry of PBT and related polyesters.
三种商用聚对苯二甲酸丁二酯(PBT)样品Pocan B1300 (B13), Pocan B1600 (B16)和Addigy p1210 (AP121)作为退火实验的起始材料,分别在添加和不添加酯化和酯交换催化剂的情况下进行了退火实验。催化剂为Sn(II) 2-乙基己酸酯(SnOct₂)、Zr(IV)乙酰丙酮酸酯和4-甲苯磺酸(TSA)。温度在150到210摄氏度之间变化。采用差示扫描量热法(DSC)、凝胶渗透色谱法(GPC)、小角度x射线散射法(SAXS)和基质辅助激光解吸/电离飞行时间质谱法(MALDI TOF)对PBT样品进行了表征。3种样品的MALDI质谱差异较大,但均存在循环的质量峰。用SnOct₂或Zr(acac)₄退火也得到了类似的结果,这有利于在m/z 5000以下的质量范围内形成偶数循环,并且降解缓慢。TSA倾向于更密集的降解,而不形成循环,甚至破坏循环。具有两个羧基(COOH)末端基团的PBT链在所有情况下都是最稳定的物种。AP121极高熔点(241-242℃)的原因可以解释为通过酯交换作用使晶体表面平滑。结果表明,将MALDI质谱法与SAXS测量相结合,为更好地了解PBT及其相关聚酯的固态化学性质提供了新的途径。
{"title":"Poly(butylene terephthalate): About condensation, cyclization, degradation and elimination reactions in the solid state, and the role of smooth crystal surfaces","authors":"Hans R. Kricheldorf ,&nbsp;Steffen M. Weidner ,&nbsp;Andreas Meyer","doi":"10.1016/j.polymdegradstab.2025.111862","DOIUrl":"10.1016/j.polymdegradstab.2025.111862","url":null,"abstract":"<div><div>Three commercial poly(butylene terephthalate) (PBT) samples - Pocan B1300 (B13), Pocan B1600 (B16), and Addigy P 1210 (AP121) - served as the starting materials for the annealing experiments, which were conducted with and without the addition of esterification and transesterification catalysts. The catalysts used were Sn(II) 2-ethylhexanoate (SnOct₂), Zr(IV) acetylacetonate, and 4-toluene sulfonic acid (TSA). Temperatures varied between 150 and 210 °C. The PBT samples were characterized using differential scanning calorimetry (DSC), gel permeation chromatography (GPC), small-angle X-ray scattering (SAXS), and matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry. The MALDI mass spectra of all three samples differed greatly but displayed mass peaks of cycles. Similar results were produced by annealing with SnOct₂ or Zr(acac)₄, which favored the formation of even-numbered cycles within the mass range below <em>m/z</em> 5000, along with slow degradation. TSA favored a more intensive degradation without the formation of cycles or even with the destruction of cycles. PBT chains with two carboxylic (COOH) end groups were the most stable species under all circumstances. The origin of the extremely high melting point of AP121 (241–242 °C) can be explained by the smoothing of crystallite surfaces via transesterification. The results suggest that combining MALDI mass spectrometry and SAXS measurements provides a new way to better understand the solid-state chemistry of PBT and related polyesters.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"245 ","pages":"Article 111862"},"PeriodicalIF":7.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789187","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}
引用次数: 0
Effects of artificial accelerated aging on the pyrolysis and combustion properties of building external insulation materials and fire risk 人工加速老化对建筑外保温材料热解燃烧性能及火灾危险性的影响
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111864
Zhenxiang Tao , Xubo Huang , Bo Yang , Yisen Wang , Tong Xu , Jiansong Wu , Rui Yang
The insulation layer of external wall insulation systems undergoes progressive degradation due to prolonged exposure to ultraviolet radiation and temperature-humidity cycles Especially when the outer protective layer is damaged or peels off detached, exposing the polymer material to the external environment, the aging process accelerates significantly. In this study, three common insulation materials—expanded polystyrene (EPS), extruded polystyrene (XPS), and rigid polyurethane (RPU)—were subjected to artificial accelerated aging conditions under controlled conditions that simulated the radiation and thermal effects. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and thermogravimetric analysis were employed to elucidate the mechanisms by which aging affects the chemical structure. Cone calorimetry was used to evaluate the ignition characteristics, heat release, smoke production, and gas product toxicity of the aged insulation materials. An entropy-weighted insulation fire risk model quantified the evolving fire risk profiles of these aged insulation materials. After 150 aging cycles, the time to ignition of both EPS and XPS was significantly shortened, and the peak heat release rates increased by 25 % and 37 % respectively. Furthermore, after aging, the total heat release and total smoke production of RPU increased by 27 % and 16 %, respectively, at a radiant heat flux of 50 kW/m². Overall, RPU pronounced a significant increase in fire hazard under high level heat exposure. These findings provide valuable guidance for the aging-resistant design of external insulation systems and the management of aging fire risks.
外墙保温系统的保温层由于长时间暴露于紫外线辐射和温湿度循环下而逐渐退化,特别是当外层保护层受损或脱落,高分子材料暴露于外界环境时,老化过程明显加速。在这项研究中,三种常见的绝缘材料-膨胀聚苯乙烯(EPS),挤压聚苯乙烯(XPS)和硬质聚氨酯(RPU) -在模拟辐射和热效应的受控条件下进行人工加速老化。采用扫描电子显微镜(SEM)、傅里叶红外(FTIR)和热重分析等方法对老化影响化学结构的机理进行了研究。采用锥量热法对老化保温材料的着火特性、放热特性、产烟特性和气体产物毒性进行了评价。一个熵加权绝热材料火灾风险模型量化了这些老化绝热材料火灾风险的演变特征。经过150次老化循环后,EPS和XPS的点火时间均显著缩短,峰值放热率分别提高了25%和37%。老化后,在辐射热通量为50 kW/m²时,RPU的总放热量和总产烟量分别增加了27%和16%。总的来说,RPU宣布在高水平的热暴露下火灾危险显著增加。研究结果为建筑外保温系统的耐老化设计和老化火灾风险管理提供了有价值的指导。
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引用次数: 0
X-ray irradiation-induced real-time conductivity evolution and cumulative damage effects of epoxy-based shape memory polymers x射线辐照诱导环氧基形状记忆聚合物的实时电导率演化和累积损伤效应
IF 7.4 2区 化学 Q1 POLYMER SCIENCE Pub Date : 2025-12-15 DOI: 10.1016/j.polymdegradstab.2025.111863
Jiale Mao , Chenyang Li , Likang Zhou , Min Li , Jing Li , Shuang Wang , Yu Chen , Zicai Shen
Shape memory polymers (SMPs) for space deployable structures, as a new type of smart material, whose adaptivity to space environments plays a crucial role in ensuring the long-term stable operation of next-generation spacecraft. This study systematically investigates the real-time photoconductive response and cumulative damage effects of SMPs with varying crosslinking network architectures under X-ray irradiation. By tailoring the curing agent functionality and mass ratios, a series of SMPs are synthesized and evaluated through shape memory behavior, thermodynamic and dielectric properties, and conductivity characteristics with and without X-ray irradiation. The research emphasizes the effects of X-ray irradiation on their dielectric properties, not only examining damage effects but also closely monitoring the real-time evolution of charge transport properties during irradiation, with the influence of temperature on these properties simultaneously considered. The results demonstrate that X-ray exposure induces a sharp increase in conductivity, with an effect significantly greater than that of temperature, accompanied by a phenomenon resembling current saturation. And at high doses accumulation, leads to partial chain scission and the formation of new functional groups, indicating a simultaneous process of degradation and re-crosslinking. This work provides a foundational understanding of radiation effects on epoxy SMPs and practical guidance for their use in high-radiation environments.
空间可展开结构的形状记忆聚合物(SMPs)作为一种新型智能材料,其对空间环境的适应性对保证下一代航天器的长期稳定运行起着至关重要的作用。本研究系统地研究了具有不同交联网络结构的SMPs在x射线照射下的实时光导响应和累积损伤效应。通过调整固化剂的功能和质量比,合成了一系列smp,并通过形状记忆行为、热力学和介电性能以及在x射线照射和不照射下的电导率特性来评估smp。本研究着重研究了x射线辐照对其介电性能的影响,不仅考察了损伤效应,还密切监测了辐照过程中电荷输运性质的实时演变,同时考虑了温度对这些性质的影响。结果表明,x射线暴露诱导电导率急剧增加,其影响明显大于温度,并伴有类似电流饱和的现象。并且在高剂量积累时,导致部分链断裂并形成新的官能团,表明降解和重新交联的同时过程。这项工作为环氧树脂SMPs的辐射效应提供了基础认识,并为其在高辐射环境中的使用提供了实用指导。
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Polymer Degradation and Stability
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