High temperature polymer is developed!

Polymer materials have many excellent properties, such as light weight, flexibility, corrosion resistance, easy processing and low cost.

In theory, the classical model shows that the inherent breakdown strength of polymer dielectric materials is higher than 1000 MV/m, because polymer dielectric materials have a large energy band gap and the mean free path of moving charges is small.

Electrostatic interactions between molecular chains are widely present in all polymers.

Recently, the laboratory of Professor Qiming Zhang from Pennsylvania State University demonstrated that this blending strategy through strong electrostatic interaction between chains can be effectively applied to several widely used high-temperature polymer dielectric films, including polyimide ( PI) and polyetherimide (PEI) (and polyethersulfone, PSU), increase the packing density of the film molecular chain, reduce the defect sites introduced during the molding process, thereby significantly improving their room temperature and high temperature (200 ℃) breakdown strength.

Molecular chain stacking behavior

As shown in the figure, PI has two strongly positively charged phenyl groups, while PEI has three relatively negatively charged phenyl groups.

Dielectric properties of PI/PEI blend film

The strategy proposed in this paper that uses strong electrostatic interactions between molecules for blending can be produced in batches at low cost.

Qiyan Zhang, Xin Chen and Bing Zhang are the co-first authors of the paper.