Quantitative Dissection of Relaxation Processes in Hybrid Epoxy Composites: Combining Dielectric Spectroscopy with Activation Energy Analysis.

IF 4.7 3区工程技术 Q1 POLYMER SCIENCE

Polymers Pub Date : 2025-05-20 DOI:10.3390/polym17101405

Xingqiao Li, Hongliang Zhang, Yansheng Bai, Hai Jin, Hong Wang, Kangle Li, Xiaonan Li

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引用次数: 0

Abstract

The dielectric relaxation dynamics in polymer composites critically determine their functional performance in advanced electrical systems. This study systematically investigates hybrid epoxy composites comprising neat epoxy resin (EP) and paper-reinforced systems (EIP), modified with 10-50 wt% polypropylene glycol diglycidyl ether (PEGDGE) plasticizer. Through synergistic application of differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (10^-1-10⁶ Hz), the quantitative relationships between plasticizer content, glass transition temperature (Tg), and dielectric relaxation processes were established. DSC analysis reveals a linear Tg dependence with increasing PEGDGE content, attributed to enhanced molecular mobility. Dielectric characterization demonstrates three distinct relaxation regimes: α-relaxation below Tg, interfacial polarization at epoxy/PEGDGE boundaries, and paper/epoxy interfacial effects in EIP systems. A quantitative dielectric relaxation model was developed based on complex modulus formalism, coupled with Vogel-Fulcher-Tammann (VFT) analysis of DC conductivity. Activation energy mapping through Arrhenius decomposition reveals three characteristic values: (1) 82.01-87.80 kJ/mol for α-relaxation, (2) 55.96-64.64 kJ/mol for epoxy/PEGDGE interfaces, and (3) 30.88-44.38 kJ/mol for epoxy/paper interfaces. Crucially, the plasticizer content modulates these activation energies, demonstrating its role in tailoring interfacial dynamics.

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杂化环氧复合材料弛豫过程的定量剖析：结合介电光谱和活化能分析。

聚合物复合材料的介电弛豫动力学决定了其在先进电气系统中的功能性能。本研究系统地研究了混合环氧复合材料，包括纯环氧树脂（EP）和纸增强体系（EIP），用10- 50%重量的聚丙烯乙二醇二缩水甘油醚（PEGDGE）增塑剂改性。通过差示扫描量热法（DSC）和宽带介电光谱（10-1-106 Hz）的协同应用，建立了增塑剂含量、玻璃化转变温度（Tg）和介电弛豫过程之间的定量关系。DSC分析显示，随着PEGDGE含量的增加，分子迁移率提高，Tg呈线性依赖关系。介电特性显示了三种不同的弛豫机制：Tg以下的α-弛豫，环氧树脂/PEGDGE边界的界面极化，以及EIP体系中的纸/环氧树脂界面效应。结合直流电导率的VFT （Vogel-Fulcher-Tammann）分析，建立了基于复模量形式化的定量介质弛豫模型。Arrhenius分解活化能映射得到三个特征值：(1)α-弛缓82.01 ~ 87.80 kJ/mol,(2)环氧树脂/PEGDGE界面55.96 ~ 64.64 kJ/mol,(3)环氧树脂/纸界面30.88 ~ 44.38 kJ/mol。至关重要的是，增塑剂的含量调节了这些活化能，证明了它在调整界面动力学中的作用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Polymers POLYMER SCIENCE-

CiteScore

8.00

自引率

16.00%

发文量

4697

审稿时长

1.3 months

期刊介绍： Polymers (ISSN 2073-4360) is an international, open access journal of polymer science. It publishes research papers, short communications and review papers. Our aim is to encourage scientists to publish their experimental and theoretical results in as much detail as possible. Therefore, there is no restriction on the length of the papers. The full experimental details must be provided so that the results can be reproduced. Polymers provides an interdisciplinary forum for publishing papers which advance the fields of (i) polymerization methods, (ii) theory, simulation, and modeling, (iii) understanding of new physical phenomena, (iv) advances in characterization techniques, and (v) harnessing of self-assembly and biological strategies for producing complex multifunctional structures.