Increasing Twist Rigidity to Prepare Polyimides with Low Dielectric Constants and Dissipation Factors over a Wide Temperature Range

• DOI: 10.1021/acs.macromol.3c01690
• Publication Date: 2023-11-23T16:55:12Z
• Authors: Yan Chen; Xinyu Chen; Yi Wang; Zhuang Nie; Xin Wang; Jiaxuan Tan; Yongbing Zhuang; Xiangyang Liu; Xu Wang
• Keywords: Rigidity (electromagnetism); Side chain; Dissipation factor; Atmospheric temperature range

To ensure the stable performance and extended service life of high-integrity high-power electronic devices, it is imperative for dielectric materials to consistently exhibit a low constant (Dk) dissipation factor (Df) across wide temperature range. Here, we have undertaken synthesis two distinct polyimides (PIs), namely, 6FDA-GA 6FDA-GB, featuring varying biphenyl side groups. These selected groups been intentionally incorporated impede interchain stacking PI macromolecules enhance twist rigidity mainchain. It was substantiated that smaller side-chain in 6FDA-GB are notably effective constraining rotation imide ring within main chain owing their closer proximity. This constraint has unequivocally resulted substantial increase chain. Thus, resulting film endowed wtih an expanded free volume concurrently curtailed dipole motion. combined effects led reduction both Dk Df. The exhibits value 2.70 Df 0.0022 at 10 kHz room temperature. Remarkably, even elevated temperatures up 200 °C, remains stable, with only slight (0.00386). contribution holds promise advancing comprehensive PIs understanding stability properties high temperatures.