环氧树脂固化物吸湿行为及其对介电性能的影响

doi:10.19936/j.cnki.2096-8000.20250828.008

摘要/Abstract

摘要： 为探究环氧树脂吸湿行为以及树脂吸湿后介电性能的变化规律,本研究通过改变固化剂种类制备了不同结构的环氧树脂。在70 ℃水浸条件下对固化物吸湿率进行监测,并跟踪了不同吸湿状态下固化物的介电性能。结果显示固化物吸湿变化过程符合Fick扩散模型,固化剂种类影响固化物极性和自由体积,极性决定了树脂平衡吸湿率,极性和自由体积共同决定了水分子的扩散系数。极性越大,树脂平衡吸湿率越高,极性基团越容易与水分子形成氢键阻碍水分子运动;自由体积越大,水分子的扩散通道越多,扩散越快。固化物介电性能随固化剂不同存在差异,介电常数及损耗角正切随吸湿率呈线性变化且与固化剂种类无关,可统一用线性模型进行预测,模型预测值与实测值偏差不超过10%。

关键词: 环氧树脂, 固化剂, 吸湿率, 介电常数, 损耗角正切, 复合材料

Abstract: To investigate the moisture absorption behavior of epoxy resin and the changes in its dielectric properties post-absorption, the study developed epoxy resins with various structures by varying the type of curing agent. The moisture absorption rate of the cured materials was monitored under 70 ℃ water immersion conditions, and the dielectric properties were tracked. The results indicated that the moisture absorption process followed the Fick diffusion model, the type of curing agent affects the polarity and free volume of the cured material, the polarity determines the equilibrium moisture absorption rate of the resin, and the polarity and free volume jointly determine the diffusion coefficient of water molecules. The greater the polarity, the higher the moisture absorption rate of the resin equilibrium, and the easier it is for the polar groups to form hydrogen bonds with water molecules and hinder the movement of water molecules. The larger the free volume, the more diffusion channels the water molecule has, and the faster the diffusion. The dielectric properties of the cured matter are different with different curing agents, and the dielectric constant and loss tangent change linearly with the moisture absorption rate and are independent of the type of curing agent. Based on this research, a model was developed to predict the dielectric properties of epoxy resins as a function of their moisture absorption rates, with a deviation of no more than 10% between model predictions and actual measurements.

Key words: epoxy resin, curing agent, moisture absorption rate, dielectric constant, loss tangent, composites

中图分类号:

TB332

张杜鹃, 李亚锋, 礼嵩明, 鹿海军. 环氧树脂固化物吸湿行为及其对介电性能的影响[J]. 复合材料科学与工程, 2025, 0(8): 66-73.

ZHANG Dujuan, LI Yafeng, LI Songming, LU Haijun. Moisture absorption behavior of epoxy resin cured products and its influence on the dielectric properties[J]. COMPOSITES SCIENCE AND ENGINEERING, 2025, 0(8): 66-73.

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