Yang Guoqing, Ding Nan, Jiang Chaolu, Yang Peizhi, Gao Qingqing, He Yichen, Han Lu
School of Electrical Engineering, Xi'an University of Technology, Xi'an 710054, China.
Materials (Basel). 2025 Apr 17;18(8):1840. doi: 10.3390/ma18081840.
To improve the issue of the decreased toughness and electrical performance of epoxy resin (EP) in thermal shock environments, we prepared thermoplastic polyurethane elastomer (TPU)-filled modified EP composites. We also studied the mechanical and electrical performance of these composites, which had different TPU filling contents, under thermal shock conditions. The results indicated that after 240 h of thermal cycling between -15 °C and 100 °C, the TPU/epoxy composites, when compared to unmodified EP, exhibited a 10.1% enhancement in their elastic modulus, a 15.3% increase in their elongation at break, a 22.3% improvement in their tensile strength, and a 47.8% increase in their impact strength. Moreover, their volume resistivity increased by 10.5% and their AC breakdown strength improved by 52.1%. In contrast, their dielectric constant and dielectric loss experienced reductions of 40.2% and 7.5%, respectively. This study demonstrates that introducing flexible TPU molecular chains into the resin significantly enhances the toughness of EP structures. Additionally, the new cross-linked structures formed within the TPU/EP composites improve their insulation performance under thermal shock conditions.
为改善环氧树脂（EP）在热冲击环境下韧性和电性能下降的问题，我们制备了填充热塑性聚氨酯弹性体（TPU）的改性EP复合材料。我们还研究了这些具有不同TPU填充量的复合材料在热冲击条件下的力学和电性能。结果表明，在-15℃至100℃之间进行240小时热循环后，与未改性的EP相比，TPU/环氧复合材料的弹性模量提高了10.1%，断裂伸长率增加了15.3%，拉伸强度提高了22.3%，冲击强度增加了47.8%。此外，它们的体积电阻率提高了10.5%，交流击穿强度提高了52.1%。相比之下，它们的介电常数和介电损耗分别降低了40.2%和7.5%。本研究表明，将柔性TPU分子链引入树脂中可显著提高EP结构的韧性。此外，TPU/EP复合材料内部形成的新交联结构改善了它们在热冲击条件下的绝缘性能。
