High-temperature polymers with record-high breakdown strength enabled by rationally designed chain-packing behavior in blends

By Qiyan Zhang, Xin Chen, Bing Zhang, Tian Zhang, Wen-Ling Lu, Zhe Chen, Ziyu Liu, Seong H. Kim, Brian F. Donovan, R. Warzoha and 3 more. Matter, 2021

207 citations recorded by the source corpus.

Summary Polymers with high dielectric breakdown strength (Eb) over a broad temperature range are vital for many applications. The presence of weak points, such as voids and free volume, severely limit the Eb of many high-temperature polymers. Here, we present a general strategy to reduce these weak points by exploiting interchain electrostatic forces in polymer blends. We show that the strong interchain electrostatic interaction between two high-temperature polymers in blends of polyimide (PI) with poly(ether imide) (PEI) yields an extended polymer chain conformation, resulting in dense chain packing and a corresponding decrease in weak spots in the polymers. This leads to a greater than 65% enhancement of Eb at room temperature and 35% enhancement at 200°C. In conjunction with results from blends of PI/poly(1,4-phenylene ether-sulfone) (PSU) and blends of PEI/PSU, we show that this previously unexplored molecular engineering strategy is efficient and straightforward in minimizing weak points in dielectric polymers.

Subfields: Biomedical Engineering, Materials Chemistry, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/0cb75150f6e08ac318f27784f53b7c2b794dadb1