Polymer Degradation and Stability最新文献_第2页

Compression stress relaxation characteristics and failure mechanism of silicone rubber for high voltage cable accessories 高压电缆附件用硅橡胶压缩应力松弛特性及失效机理

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-19 DOI: 10.1016/j.polymdegradstab.2024.111098

YanHui Wei , Hao Guo , XiaoLong Chen , XueJing Li , GuoChang Li , Yongjie Nie , YuanWei Zhu

Sufficient interfacial pressure between silicone rubber (SIR) insulation and cross-linked polyethylene (XLPE) in high-voltage cable accessories is the basic condition to ensure the normal operation of cable accessories. However, in the actual operation of cables and accessories, high-temperature aging and mechanical aging can cause the mechanical properties of SIR materials to decline, thus affecting the size of the insulation interface pressure. Firstly, the relaxation law of compressive stress of SIR material is obtained by measuring the compressive stress under force-thermal synergistic aging. Secondly, the time-temperature equivalent model is established according to the measured data to evaluate the service life of the cable accessories. Thirdly, the physical and chemical properties of SIR with different aging times are tested to analyze the change in its mechanical properties. Finally, the effect of temperature on the stress relaxation characteristics of SIR is calculated from the microscopic level by molecular simulation. The experimental results show that the compressive stress of SIR decreases first and then becomes stable with the increase of aging time due to the movement of molecular chains and chemical reactions in SIR. In addition, the compression stress relaxation rate of SIR increases with temperature. The aging life prediction model shows that when the relaxation coefficient of compressive stress drops to 50% of the initial value at the end of cable life, the service life of cable accessories at 70°C is about 24 years. The molecular simulation shows that the relaxation of the molecular chain of SIR is accelerated with the increase in temperature, and the stress relaxation of SIR material is accelerated on a macroscopic level. This research can provide a theoretical basis for the design and operation reliability of cable accessories.

高压电缆附件中硅橡胶（SIR）绝缘与交联聚乙烯（XLPE）之间有足够的界面压力是保证电缆附件正常工作的基本条件。但在电缆及附件的实际使用中，高温老化和机械老化会导致SIR材料的力学性能下降，从而影响绝缘界面压力的大小。首先，通过测量应力-热协同老化条件下SIR材料的压缩应力，得到了压缩应力的松弛规律；其次，根据实测数据建立时间-温度等效模型，对电缆附件的使用寿命进行评估。第三，对不同时效时间SIR的理化性能进行测试，分析其力学性能的变化。最后，通过分子模拟从微观层面计算了温度对SIR应力松弛特性的影响。实验结果表明，随着老化时间的延长，由于SIR中分子链的移动和化学反应，SIR的压缩应力先减小后趋于稳定，压缩应力松弛速率随温度的升高而增大。老化寿命预测模型表明，当电缆寿命结束时压应力松弛系数降至初始值的50%时，电缆附件在70℃下的使用寿命约为24年。分子模拟结果表明，SIR分子链的弛豫随着温度的升高而加速，SIR材料的应力弛豫在宏观层面上加速。该研究可为电缆附件的设计和运行可靠性提供理论依据。

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引用次数: 0

Fabrication of novel halogen-free flame retardant containing functionalized chitosan from fisheries waste through the sol-gel technology and its fire safety performance in polyurethane resin 利用溶胶-凝胶技术从渔业废料中制备含有功能化壳聚糖的新型无卤阻燃剂及其在聚氨酯树脂中的防火性能

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-19 DOI: 10.1016/j.polymdegradstab.2024.111097

Yih-Wen Wang , Chin-Lung Chiang , Cing-Yu Ke

Chitosan (CS) derived from fisheries waste, such as shrimp and crab shells, was used to fabricate a bio-based, ecofriendly flame retardant. By reacting the –NH₂ groups of CS and the NH₂ groups of melamine polyphosphate (MPP) with the NCO groups of polymethylene polyphenyl polyisocyanate (PMPI), a novel intumescent flame retardant, CS-PMPI-MPP, was synthesized. Isophorone diisocyanate (IPDI) was reacted with polyol and aminopropyltriethoxysilane (APTS) to form a polyurethane containing silicon (Si-PU), into which the flame retardant was incorporated to produce a high-polymer composite through the sol-gel technology. The structure, thermal properties, flame retardancy, mechanical properties, toxicity, and char formation of the composites were analyzed. Fourier transform infrared spectroscopy, thermogravimetric analysis, limiting oxygen index, cone calorimeter, UL-94, thermogravimetric analysis with infrared spectroscopy, universal testing machine, scanning electron microscopy, X-ray photoelectron spectroscopy, raman spectroscopy, and smoke density test analyses were performed. The thermogravimetric test results indicated an increase in char yield from 0.5 wt% in pristine polyurethane to 25.9 wt% upon the addition of CS-PMPI-MPP, signifying an enhancement in the thermal stability of pristine polyurethane. According to limiting oxygen index and UL-94 data, the incorporation of CS-PMPI-MPP improved the limiting oxygen index and UL-94 ratings from 18.2 % (Fail) to 26.5 % (V-1), demonstrating the exceptional flame-retardant property of CS-PMPI-MPP within the pristine polyurethane formulation.

从虾蟹壳等渔业废弃物中提取的壳聚糖（CS）被用于制造一种生物基生态友好型阻燃剂。通过将壳聚糖的 -NH2 基团和多磷酸三聚氰胺（MPP）的 NH2 基团与多亚甲基多苯基多异氰酸酯（PMPI）的 NCO 基团反应，合成了一种新型膨胀型阻燃剂 CS-PMPI-MPP。异佛尔酮二异氰酸酯（IPDI）与多元醇和氨基丙基三乙氧基硅烷（APTS）反应生成含硅的聚氨酯（Si-PU），并在其中加入阻燃剂，通过溶胶-凝胶技术制成高聚物复合材料。分析了复合材料的结构、热性能、阻燃性、机械性能、毒性和成炭性。分析方法包括傅里叶变换红外光谱、热重分析、极限氧指数、锥形量热仪、UL-94、热重分析与红外光谱、万能试验机、扫描电子显微镜、X 射线光电子能谱、拉曼光谱和烟密度测试分析。热重测试结果表明，添加 CS-PMPI-MPP 后，原始聚氨酯的炭产量从 0.5 wt%增加到 25.9 wt%，这表明原始聚氨酯的热稳定性得到了提高。根据极限氧指数和 UL-94 数据，加入 CS-PMPI-MPP 后，极限氧指数和 UL-94 评级从 18.2% (Fail) 提高到 26.5% (V-1)，这表明 CS-PMPI-MPP 在原始聚氨酯配方中具有优异的阻燃性能。

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引用次数: 0

Facile synthesis of novel soy protein-based flame retardant and its effects on the flame retardancy and biodegradation of polylactic acid 新型大豆蛋白基阻燃剂的简易合成及其对聚乳酸阻燃性和生物降解的影响

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-17 DOI: 10.1016/j.polymdegradstab.2024.111093

Yuting Xue , Dongfang Zhao , Luqian Dong , Ruobing Yao , Fang Xu , Yunxuan Weng

A novel soy protein-based phosphonate flame retardant (SPPU) was synthesized by a facile two-step method for PLA. And the flame-retardant PLA/SPPU composites were prepared by melt blending. From the results, 3 wt.% of SPPU could increase the limiting oxygen index (LOI) value of PLA from 19.4 % to 23.4 %, and reach V-0 grade in UL-94 vertical combustion test. In the cone calorimetric tests, the heat release rate (HRR) and total heat release (THR) of PLA/SPPU decreased significantly. The results of TG and TG-IR of PLA/SPPU, FTIR and XPS of the char residual showed that SPPU mainly exerted flame retardant effects in the gas phase, accompanied by some effects in condensed phase. Besides, SPPU could accelerate the biodegradation of PLA under compost conditions, which increased the biodegradation rate of PLA from 86.2 % to 88.39 % in 180 days. The addition of appropriate content of SPPU would not cause the deterioration of mechanical properties of PLA, but can improve the toughness of PLA.

采用简便的两步法合成了一种新型大豆蛋白基膦酸盐阻燃剂（SPPU）。通过熔融混合制备了阻燃聚乳酸/SPPU 复合材料。结果表明，3 wt.%的SPPU可将聚乳酸的极限氧指数（LOI）值从19.4%提高到23.4%，在UL-94垂直燃烧测试中达到V-0级。在锥形量热试验中，聚乳酸/SPPU 的热释放率（HRR）和总热释放率（THR）明显下降。聚乳酸/SPPU的TG和TG-IR、残炭的傅立叶变换红外光谱和XPS结果表明，SPPU主要在气相中发挥阻燃作用，在凝结相中也有一定作用。此外，在堆肥条件下，SPPU 还能加速聚乳酸的生物降解，180 天内聚乳酸的生物降解率从 86.2% 提高到 88.39%。添加适当含量的 SPPU 不会导致聚乳酸的机械性能下降，反而能提高聚乳酸的韧性。

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引用次数: 0

Preparation of eugenol-based flame retardant epoxy resin with an ultrahigh glass transition temperature via a dual-curing mechanism 通过双重固化机制制备具有超高玻璃化转变温度的丁香酚基阻燃环氧树脂

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-17 DOI: 10.1016/j.polymdegradstab.2024.111092

Kangle Xue , Pengbo Zhang , Zidie Song , Fanjun Guo , Zibo Hua , Tao You , Shumao Li , Chao Cui , Li Liu

Eugenol epoxy resin, as one of the most promising biobased epoxy resins, still faces problems of insufficient heat resistance, high flammability, and complicated synthesis processes. Based on the principles of the Diels–Alder (D-A) addition reaction and epoxy-amine open-loop crosslinking, the EUEP epoxy monomer (EUEP) was synthesized, and ternary cocuring (EUEP-BDM-DDS) was performed with bismaleimide (BDM) and the high-temperature curing agent 4,4′-diamino-diphenyl sulfone (DDS). The resulting system exhibited an exceptional glass transition temperature (T_g) of 306 °C, surpassing other eugenol epoxies and commercial bisphenol A epoxies. EUEP-BDM-DDS demonstrated superior mechanical properties with high moduli (up to 4.14 GPa for tensile and 4.10 GPa for flexural). Its processing characteristics were also favorable, featuring a long pot-life, low viscosity, and suitable for all operating processes of traditional DGEBA-DDS systems. In addition, the formation of rigid six-membered rings during curing and the higher cross-linking density gave the resin system excellent flame retardant properties, with a limit oxygen index of 33.5 % and passing the V-0 class test of UL-94. The system exhibited significantly lower peak heat release and smoke release rates compared to DGEBA-DDS, indicating enhanced fire safety. And the analysis revealed a coacervated flame retardant mechanism. Moreover, the composite material derived from EUEP-BDM-DDS displayed improved interlaminar shear strength, flexural strength, and high-temperature mechanical properties, outperforming the DGEBA-DDS system. This study paves the way for utilizing biobased eugenol epoxy resins in advanced composite materials, offering enhanced performance and fire safety. It holds significant implications for promoting the application of biobased materials in high-performance composites.

丁香酚环氧树脂作为最具发展前景的生物基环氧树脂之一，仍然面临着耐热性不足、易燃性高、合成工艺复杂等问题。根据狄尔斯-阿尔德（D-A）加成反应和环氧胺开环交联原理，合成了 EUEP 环氧单体（EUEP），并与双马来酰亚胺（BDM）和高温固化剂 4,4′-二氨基二苯砜（DDS）进行了三元共固化（EUEP-BDM-DDS）。由此产生的系统显示出 306 °C 的超高玻璃化转变温度 (Tg)，超过了其他丁香酚环氧树脂和商用双酚 A 环氧树脂。EUEP-BDM-DDS 具有优异的机械性能和高模量（拉伸模量高达 4.14 GPa，弯曲模量高达 4.10 GPa）。它的加工特性也很好，具有长固化时间、低粘度的特点，适用于传统 DGEBA-DDS 系统的所有操作流程。此外，固化过程中形成的刚性六元环和较高的交联密度使该树脂体系具有优异的阻燃性能，极限氧指数为 33.5%，通过了 UL-94 的 V-0 级测试。与 DGEBA-DDS 相比，该体系的峰值热释放率和烟雾释放率明显降低，这表明其防火安全性得到了提高。分析结果表明，该系统具有凝聚阻燃机制。此外，由 EUEP-BDM-DDS 制成的复合材料在层间剪切强度、抗弯强度和高温机械性能方面均有改善，优于 DGEBA-DDS 系统。这项研究为在先进复合材料中使用生物基丁香酚环氧树脂铺平了道路，从而提高了复合材料的性能和防火安全性。它对促进生物基材料在高性能复合材料中的应用具有重要意义。

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引用次数: 0

In-situ generated SiO2 nanoparticles for heat release reduction and smoke suppression in unsaturated polyester composites 在不饱和聚酯复合材料中减少热释放和抑制烟雾的原位生成二氧化硅纳米粒子

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-16 DOI: 10.1016/j.polymdegradstab.2024.111095

Arvindh Sekar, Nicolas Chauvet, Sandro Lehner, Milijana Jovic, Sithiprumnea Dul, Patrick Rupper, Sabyasachi Gaan

Achieving lower heat release rates (HRR) during combustion is one of the key steps toward obtaining flame retardant materials. UPR thermosets, while mechanically strong and chemically durable, show high HRR upon ignition. While most commercial applications focus on blending of metal oxide or other heterogeneous fillers to reduce HRR, they have significant drawbacks like phase segregation, drop in transparency and other features which disfavor their use in UPRs. Herein, a novel, green technique to generate nSiO₂ in-situ in UPRs is demonstrated. The method is designed such that the precursors act as nucleating agents covalently bonded to the UPRs and as growth fuel for the nSiO₂ production. Apart from major advantages like a uniform phase distribution in the thermoset and transparency, this technique also prevents direct handling of powdered micro or nanoparticles, leading to a safer working environment for the handling of UPRs. The physical, thermal, and mechanical properties analyzed show great promise towards flame retardant composites, as the formed nanocomposite material, with 10 wt% loading of nSiO₂ demonstrates a 41 % reduction in total heat release (THR) and a 52 % reduction in total smoke release (TSR), while retaining optical transmission >90 %. On combination with commercial phosphorus containing flame retardant, ammonium polyphosphate (APP), the composite shows an even greater reduction in THR and TSR, while also being self-extinguishing. These compelling features, coupled with the safe nature of generating nanoparticles in-situ, offer substantial benefits of using this nSiO₂ approach towards HRR reduction in UPR-based thermosets and advocate for their use in commercial formulations.

降低燃烧过程中的热释放率（HRR）是获得阻燃材料的关键步骤之一。UPR 热固性塑料虽然具有机械强度和化学耐久性，但在点燃时会显示出较高的热释放率。虽然大多数商业应用都侧重于混合金属氧化物或其他异质填料以降低 HRR，但它们存在相分离、透明度下降等显著缺点，不利于在 UPR 中使用。本文展示了一种在 UPR 中原位生成 nSiO2 的新型绿色技术。设计该方法的目的是使前驱体作为成核剂与 UPR 共价结合，并作为 nSiO2 生成的生长燃料。除了热固性相分布均匀和透明等主要优点外，该技术还可避免直接处理粉末状微粒或纳米粒子，从而为处理 UPR 提供更安全的工作环境。对物理、热和机械性能的分析表明，阻燃复合材料大有可为，因为所形成的纳米复合材料中 nSiO2 的含量为 10 wt%，在保持 90% 光学透射率的同时，总热量释放量（THR）减少了 41%，总烟雾释放量（TSR）减少了 52%。在与商用含磷阻燃剂聚磷酸铵（APP）结合使用时，复合材料的总热量释放（THR）和总烟雾释放（TSR）降低幅度更大，同时还具有自熄功能。这些引人注目的特性，加上在原位生成纳米颗粒的安全性，为使用这种 nSiO2 方法降低基于 UPR 的热固性塑料的 HRR 带来了巨大的好处，并倡导将其用于商业配方中。

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引用次数: 0

Hydrolysis of poly(ester urethane): In-depth mechanistic pathways through FTIR 2D-COS spectroscopy 聚酯聚氨酯的水解：通过傅立叶变换红外 2D-COS 光谱深入研究机理途径

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-16 DOI: 10.1016/j.polymdegradstab.2024.111094

Dali Yang, Jack K. Brett, Mathias C. Celina

The hydrolysis of thermoplastic poly(ester urethane) (PEU) is convoluted by its block copolymer phase structure and competing hydrolytic sensitivities of multiple functional groups. The exact pathways for water ingress, water interaction with the material and ultimately the kinetics and order of functional group hydrolysis remain to be refined. Additional diagnostics are needed to enable deeper insight and deconvolution of material changes. In combination with GPC results, a promising analytical technique – two-dimensional correlation spectroscopy (2D-COS) – has been reviewed and applied to analyze FTIR spectra of hydrolyzed PEUs aged under various conditions, such as exposure time, temperature, and relative humidity. 2D-COS allows the complex role of water with distinct intermediate steps to be established, plus it emphasizes the initial stages of PEU hydrolysis at more susceptible functional groups. As a complication for the raw material, ATR IR detected some talc on the surface of commercial PEU beads and pressed sheets thereof, which can interfere with water ingress and thereby retards PEU hydrolysis, particularly in its natural form or moderate aging at lower temperatures (e.g., below the melting point of PEU). As aging temperature increases above the melting temperature, even traces of water trapped inside the PEU are sufficient to initiate the hydrolysis, which then progresses strongly with increasing temperatures. Feedback from 2D-COS analysis confirms that PEU hydrolysis starts at esters in the soft-segments before those in the urethane linkage become susceptible. Only when the molecular weight of PEU is below a critical molar mass (M_c) will the hydrolysis occur in parallel in the hard-segments since protective morphological phase structures are then absent. The current observations demonstrate unexpected behavior that may result from 'unknown' additives in polymer degradation, the temporal and group-specific hydrolysis of PEU as a function of locally available water molecules, the order of reactivity of susceptible functional groups, and the importance of changes in molecular weight coupled with the phase structure of the polymer.

热塑性聚（酯聚氨酯）（PEU）的水解过程因其嵌段共聚物相结构和多个官能团相互竞争的水解敏感性而错综复杂。进水的确切途径、水与材料的相互作用以及最终官能团水解的动力学和顺序仍有待完善。需要更多的诊断方法来深入了解和分解材料的变化。结合 GPC 结果，对一种很有前景的分析技术--二维相关光谱（2D-COS）--进行了审查，并将其应用于分析在暴露时间、温度和相对湿度等各种条件下老化的水解聚乙烯醇的傅立叶变换红外光谱。2D-COS 可以确定水的复杂作用和不同的中间步骤，还能强调 PEU 在较易受官能团影响的水解初始阶段。作为原材料的一个复杂因素，ATR IR 在商用聚乙烯醇珠及其压制片材的表面检测到一些滑石粉，这些滑石粉会干扰水的进入，从而延缓聚乙烯醇的水解，尤其是在其天然形态或在较低温度（如低于聚乙烯醇熔点）下进行适度老化的情况下。当老化温度升高到熔点以上时，即使 PEU 内部残留的微量水也足以启动水解作用，然后随着温度的升高，水解作用会更加剧烈。2D-COS 分析的反馈信息证实，聚乙烯醇的水解始于软段中的酯类，然后才是氨基甲酸乙酯连接中的酯类。只有当 PEU 的分子量低于临界摩尔质量 (Mc)时，硬段中才会同时发生水解，因为此时不存在保护性形态相结构。目前的观察结果表明，在聚合物降解过程中，"未知 "添加剂可能会产生意想不到的行为，PEU 的时间性和特定基团水解是局部可用水分子的函数，易受影响的官能团的反应顺序，以及分子量变化与聚合物相结构耦合的重要性。

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引用次数: 0

Sustainable biocomposites based on Mater-Bi and grape pomace for a circular economy: Performance evaluation and degradation in soil 基于 Mater-Bi 和葡萄渣的可持续生物复合材料，促进循环经济：性能评估和在土壤中的降解

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-15 DOI: 10.1016/j.polymdegradstab.2024.111091

Vincenzo Titone , Marco Rapisarda , Luana Pulvirenti , Edoardo Napoli , Giuseppe Impallomeni , Luigi Botta , Maria Chiara Mistretta , Paola Rizzarelli

Biodegradable polymers often exhibit inferior properties and higher cost compared to their fossil-derived counterparts. The addition of plant waste and by-products can improve their performances, providing in the meantime functional activity and reducing their cost. In this work, we summarize the preparation of different biocomposites (BioCs) incorporating two diverse amounts (10 % and 20 %) of grape pomace (GP) in a Mater-Bi (MB) sample. GP, MB as well as BioCs were fully characterized. The influence of addition of GP on the properties and degradation in soil of the biocomposites was evaluated in comparison with the neat MB. However, natural antioxidants and other active compounds from GP could be sensitive to temperature. Thus, GP and MB underwent heat treatment at 180 °C to simulate and induce possible degradation during BioCs processing. GP analysis (particle size 50 μm) showed only a slight decrease of antioxidant potency, despite the heat treatment simulating the BioCs processing. ¹H NMR of the MB soluble fraction in CDCl₃ displayed the presence of two polymeric components: polylactide (PLA) and poly(butylene adipate-co-butylene terephthalate) (PBAT). Introduction of GP in the polymer matrix induced a proportional increase of antioxidant property in the BioCs as well as in complex viscosity at low frequencies. Moreover, a slight increase in the elastic modulus was observed with increasing the crystallinity of the samples. Degradation rate in soil, monitored by weight loss, increased with filler content and time. Moreover, NMR showed that, in the recovered sample after 45 days, the composition of PBAT changed, with the terephthalic percentage increased.

与化石衍生的聚合物相比，生物可降解聚合物通常性能较差，成本较高。添加植物废料和副产品可以改善其性能，同时提供功能活性并降低成本。在这项工作中，我们总结了不同生物复合材料（BioCs）的制备方法，在材料-生物（MB）样品中加入了两种不同数量（10 % 和 20 %）的葡萄渣（GP）。对 GP、MB 以及 BioCs 进行了全面表征。与纯甲基溴相比，评估了添加 GP 对生物复合材料特性和在土壤中降解的影响。然而，GP 中的天然抗氧化剂和其他活性化合物可能对温度敏感。因此，对 GP 和 MB 进行了 180 °C 的热处理，以模拟和诱导生物复合材料加工过程中可能发生的降解。对 GP（粒径为 50 μm）的分析表明，尽管进行了模拟 BioCs 加工的热处理，但其抗氧化效力仅略有下降。MB 可溶部分在 CDCl3 中的 1H NMR 显示存在两种聚合物成分：聚乳酸（PLA）和聚对苯二甲酸丁二醇酯（PBAT）。在聚合物基质中引入 GP 会诱导 BioCs 的抗氧化性和低频复合粘度成比例地增加。此外，随着样品结晶度的提高，弹性模量也略有增加。根据重量损失监测，土壤中的降解率随着填料含量和时间的增加而增加。此外，核磁共振显示，在 45 天后回收的样品中，PBAT 的成分发生了变化，对苯二甲酸的比例增加了。

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引用次数: 0

A high-molecular-weight flame retardant derived from bis[tetrakis(hydroxymethyl)phosphonium] sulfate for cotton fabrics 用于棉织物的双[四（羟甲基）膦]硫酸盐高分子量阻燃剂

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-15 DOI: 10.1016/j.polymdegradstab.2024.111075

Shuo Diao , Mengxiao Liang , Yonghua Lu , Yan Yang , Qian Tang , Guangxian Zhang

A high-molecular-weight flame retardant, bis[tetrakis(hydroxymethyl)phosphonium] (THPS)-urea_n-(PO₃)(NH₄)₂, was synthesized for cotton fabrics. Fourier-transform infrared spectroscopy, nuclear magnetic spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy analyses confirmed that (THPS-urea)_n-(PO₃)(NH₄)₂ effectively infiltrated the fibers and grafted onto cellulose through N–P(=O)–O–C covalent bonds. The fabric treated with 30 wt% of (THPS-urea)_n-(PO₃)(NH₄)₂ (C30) had a limiting oxygen index of 46.8 %. Even after 50 laundering cycles according to the AATCC 61-2013 3A standard, C30 maintained a limiting oxygen index of 39.8 %. Thermogravimetric-Fourier-transform infrared spectrometry, thermogravimetry, and cone calorimetry tests revealed that C30 exhibited excellent flame retardancy. Upon exposure to flame, C30 formed a stable char layer, which prevented the spread of heat and combustible gases. Additionally, C30 was free of formaldehyde, making it suitable for producing infant textiles. After grafting with the flame retardant, C30 retained its mechanical properties. The high-molecular-weight flame retardant enhanced the flame resistance and durability of cotton materials owing to its numerous N–P(=O) (ONH₄)₂ groups, which facilitated a condensed-phase flame retardancy mechanism.

为棉织物合成了一种高分子量阻燃剂--双[四（羟甲基）膦]（THPS）-脲-(PO3)(NH4)2。傅立叶变换红外光谱、核磁光谱、扫描电子显微镜和 X 射线光电子能谱分析证实，(THPS-脲)n-(PO3)(NH4)2 能有效渗入纤维，并通过 N-P(=O)-O-C 共价键接枝到纤维素上。使用 30 wt%（THPS-脲）n-(PO3)(NH4)2（C30）处理的织物的极限氧指数为 46.8%。即使按照 AATCC 61-2013 3A 标准洗涤 50 次后，C30 的极限氧指数仍保持在 39.8%。热重-傅立叶变换红外光谱法、热重法和锥形量热法测试表明，C30 具有优异的阻燃性。暴露在火焰中时，C30 会形成稳定的炭层，从而阻止热量和可燃气体的扩散。此外，C30 不含甲醛，因此适用于生产婴儿纺织品。与阻燃剂接枝后，C30 仍能保持其机械性能。这种高分子量阻燃剂由于含有大量 N-P(=O) (ONH4)2 基团，促进了凝聚相阻燃机制，从而提高了棉材料的阻燃性和耐用性。

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引用次数: 0

Analysis of Poly(ethylene glycol) from the conservation of 17th century shipwreck Vasa and associated wooden objects 17世纪沉船“瓦萨”号及相关木制品中聚乙二醇的分析

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-15 DOI: 10.1016/j.polymdegradstab.2024.111090

Brennan J. Curole , Malin Sahlstedt , Scott M. Grayson

Vasa, a Swedish warship that sunk in 1628 and was excavated in 1961, and associated wooden objects underwent a preservation process using various low molecular weights (600, 1500, and 4000 M_n) of poly(ethylene glycol) (PEG) to gradually displace the water within the wooden structure, preventing the collapse of the waterlogged wood upon drying. However, after six decades of aging after application, to what extent are these polymers degraded? To investigate this, a Soxhlet apparatus was used to extract PEG from wooden samples of Vasa, and lyophilization was used to dry aqueous PEG solutions, these samples being the runoff accumulated during the application of different molecular weights of PEG to Vasa and other associated wooden objects. These samples underwent analysis via matrix-assisted laser desorption/ionization – time-of-flight mass spectrometry (MALDI-TOF MS), gel permeation chromatography (GPC), and ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy.

The primary discovery was that the PEG within Vasa exhibited minimal degradation, with the dominant identified species, as determined by MALDI-TOF MS and NMR spectroscopy, being HO-PEG-OH. However, small quantities of HO-PEG-OH had undergone degradation, resulting in the formation of PEG chains with distinct end groups, notably a range of carbonyl-based compounds, including aldehydes, carboxylic acids, and esters, as observed through MALDI-TOF MS, ¹H, and ¹³C NMR spectroscopy. These mass spectrometry product peaks could be confirmed by the expected mass difference through various end-group functionalizations, such as oxidations, esterifications, or ether formations. In addition to the carbonyl-based degradation products, some PEG chains had completely cleaved into two separate lower molecular weight HO-PEG-OH polymers, each approximately half of their original molecular weight, as revealed by GPC analysis.

1628年沉没、1961年出土的瑞典战舰瓦萨号（Vasa）和相关的木制品使用各种低分子量（600、1500和4000 Mn）聚乙二醇（PEG）进行保存，以逐渐取代木结构内的水，防止浸水木材在干燥时坍塌。然而，经过60年的老化后，这些聚合物降解到什么程度？为了研究这一点，我们使用索氏装置从Vasa的木制样品中提取PEG，并使用冻干方法干燥PEG水溶液，这些样品是不同分子量的PEG在Vasa和其他相关木制物体上应用期间积累的径流。这些样品通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）、凝胶渗透色谱（GPC）和1H和13C核磁共振（NMR）谱分析。主要发现是Vasa中的PEG表现出最小的降解，通过MALDI-TOF MS和NMR波谱确定的优势鉴定物种是HO-PEG-OH。然而，少量的HO-PEG-OH经过降解，形成具有不同端基的PEG链，特别是通过MALDI-TOF MS， 1H和13C NMR光谱观察到的一系列羰基化合物，包括醛类，羧酸类和酯类。这些质谱产物峰可以通过各种端基功能化（如氧化、酯化或醚形成）的预期质量差来确认。GPC分析显示，除了羰基降解产物外，一些PEG链已经完全分裂成两个独立的低分子量HO-PEG-OH聚合物，每个聚合物的分子量约为原始分子量的一半。

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引用次数: 0

An efficient approach to identifying optimum dosages of the two-component synchronous rejuvenator composite for rejuvenating the aged SBS-modified asphalt 确定用于老化 SBS 改性沥青再生的双组分同步再生剂复合材料最佳用量的有效方法

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability

Pub Date : 2024-11-14 DOI: 10.1016/j.polymdegradstab.2024.111088

Peixin Xu , Derun Zhang , Ziyang Liu , Piergiorgio Tataranni , Cesare Sangiorgi

Reconnecting fractured styrene-butadiene-styrene (SBS) polymer chains and rebalancing unstable colloidal structures of aged pure asphalt using two-component synchronous rejuvenator composite (SRC) are essential for recycling waste SBS-modified asphalt (SBSMA) mixtures. This research develops an efficient approach to identify the optimum dosages of SRC through the restoration of FTIR peak area ratios. Based on the FTIR analysis of aged SBSMA rejuvenated by triallyl isocyanurate (TAIC) (SBS repair agent) and aromatic oil (pure asphalt component regulation agent), the optimum dosage of TAIC was identified at which the FTIR peak area ratio loss at 968 cm^-1 was completely compensated by the new peak area ratios at 1022 cm^-1 and 1112 cm^-1, while the optimum dosage of aromatic oil was defined at which the loss of FTIR peak area ratios at 1376 cm^-1 and 1600 cm^-1 was fully restored. In line with this principle, seven types of aged SBSMA were prepared and rejuvenated with different dosages of TAIC and aromatic oil incorporated. Through analyzing the FTIR peak area ratios of the prepared aged SBSMAs before and after synchronous rejuvenation, a good linear relationship was found between the optimum TAIC/aromatic oil dosage and the required restoration peak area ratio. The fitting equations of y_TAIC=1.7852x+0.0229 (R²= 0.9616) and y_{Aromatic oil}=2.2809x-0.0109 (R² = 0.9395) were developed for determining the optimum dosages of two-component SRC, respectively. After adding the theoretically derived optimum dosages of TAIC and aromatic oil into three aged SBSMAs, their physical-rheological-microscopic performance was found to be restored around 90 % of the virgin ones, validating the efficiency of the newly proposed approach.

使用双组分同步再生剂复合材料（SRC）重新连接断裂的苯乙烯-丁二烯-苯乙烯（SBS）聚合物链并重新平衡老化纯沥青的不稳定胶体结构，对于回收利用废弃的 SBS 改性沥青（SBSMA）混合物至关重要。本研究开发了一种有效的方法，通过恢复傅立叶变换红外光谱峰面积比来确定 SRC 的最佳用量。根据对使用异氰尿酸三烯丙基酯（TAIC）（SBS 修复剂）和芳香油（纯沥青成分调节剂）进行再生的老化 SBSMA 的傅立叶变换红外光谱分析，确定了 TAIC 的最佳用量，即 968 cm-1 处的傅立叶变换红外峰面积比损失完全由 1022 cm-1 和 1112 cm-1 处的新峰面积比补偿，而芳香油的最佳用量则确定为 1376 cm-1 和 1600 cm-1 处的傅立叶变换红外峰面积比损失完全恢复。根据这一原则，制备了七种老化 SBSMA，并加入不同剂量的 TAIC 和芳香油使其恢复活力。通过分析所制备的老化 SBSMA 在同步年轻化前后的傅立叶变换红外峰面积比，发现 TAIC/芳香油的最佳用量与所需的恢复峰面积比之间存在良好的线性关系。分别建立了 yTAIC=1.7852x+0.0229 (R2= 0.9616) 和 y芳香油=2.2809x-0.0109 (R2= 0.9395) 的拟合方程，以确定双组分 SRC 的最佳用量。将理论上得出的 TAIC 和芳香油最佳用量添加到三种老化 SBSMA 中后，发现它们的物理流变学和显微性能恢复到了原始 SBSMA 的 90%左右，验证了新方法的有效性。

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引用次数: 0