Authors: Longbo Luo Yuwei Pang Xue Jiang Xu Wang Peng Zhang Yi Chen Chaorong Peng Xiangyang Liu
Publish Date: 2011/12/27
Volume: 19, Issue: 1, Pages: 9783-
Abstract
A novel diamine monomer 4aminoN4aminophenylbenzamide DABA containing amide group was introduced to modify the polyimide of pyromellitic dianhydride PMDA and 4 4′oxydianiline ODA by copolymerization A series of homo and copolyamic acid were synthesized by DABA and ODA in different molar ratio with PMDA and polyimide films were obtained by thermal imidization The films were characterized by tensile testing dynamic mechanical analysis DMA thermal gravimetry analysis TGA fourier transform infrared FTIR and wide xray diffraction WAXD All of the obtained polyimide films show excellent mechanical properties and thermal stability With the content of DABA increasing from 0 to 100 the tensile strength and initial modulus are highly improved from 12472 MPa and 470 GPa to 28646 MPa and 2206 GPa respectively The polyimides have 5 weight loss temperature in the range of 5300–5555 °C The glass transition temperatures are in the range of 38790–40916 °C and the tanδ values decrease from 03721 to 008316 The results of WAXD and FTIR indicate that the introduction of DABA containing amide group can improve the order degree of macromolecule and form hydrogen bonds between the main chains which results in the improvement of mechanical properties
Keywords: