Silicon-containing conductive polyurethane-imide elastomers: Unique microstructure, heat resistance, mechanical property, and conductivity

The rapid development of high-power integrated electronic devices for 5 G systems has created an urgent requirement for heat resistance and conductivity polymer materials. To further improve the heat resistance of the polyurethane-based conductive polymers (CPU), both imide and siloxane groups were introduced into CPU backbones, and conductive polyurethane-imide elastomer (CPUI) was synthesized by using P-phenylene diisocyanate (PDI), pyromellitic dianhydride (PMDA) as hard segments and extending the chain by aniline trimer (AT). The molecular structure and electrochemical activity of dissolvable CPUI were confirmed by using formal characterizations such as FTIR, 1H NMR, and electrochemical workstation. DSC, DMA, XRD, TGA, and mechanical property were conducted on the CPUI films to better understand the relation between structure and property. Results show that the introducing of PDMS effectively improved the degree of microphase separation, while the introduction of PMDA promoted the stacking and crystallinity of hard segments. The tensile strength of CPUI films is as high as 48.32 MPa and the initial thermal decomposition temperature can reach 338 °C. Due to the improvement of phase separation morphology, the heat resistance and mechanical properties of CPUI modified by both PDMS and PMDA were obviously enhanced.