Synthesis and properties of transparent random and multi-block polyamide-imide films with high modulus and low CTE. (15th June 2021)

• Record Type: Journal Article
• Authors: Lao, Haoji; Mushtaq, Nafeesa; Chen, Guofei; Wang, Bingyang; Ba, Yuxia; Fang, Xingzhong
• Is Part Of: European polymer journal. Volume 153(2021)
• Publication Date: 2021-06-15
• Subjects: Coefficient of thermal expansion -- Modulus -- Transparency -- Block copolymer -- Polyamide-imides; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2021.110512
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Two series of PAIs were synthesized for transparent films with high modulus and low CTE. The effect of TPC monomer ratios and block copolymerization on the properties was investigated. PAI-3-B1 showed excellent properties with high transparency, high modulus, and low CTE. Abstract: Two new series of transparent polyamide-imides (PAIs) with high modulus and low coefficient of thermal expansion (CTE) were prepared by random or block copolymerization of 4, 4′-biphthalic dianhydride (BPDA) and p -phthaloyl chloride (TPC) with 2, 2′-bis(trifluoromethyl)benzidine (TFDB). These series of PAIs displayed low CTE of 16–42 ppm/K, good mechanical properties with high tensile modulus ranging from 4.9 to 6.6 GPa, tensile strengths of 112–170 MPa and elongations at break of 2.0–5.4%, as well as high transparency with transmittances at 500 nm (T500nm ) of 84–87%, which was greatly affected by the feed ratio of monomer BPDA & TPC, and the block length caused by block polymerization. The block copolymer PAI-3-B1 presented the best comprehensive performance with high transparency (T500nm ) of 87%, low CTE of 16 ppm/K and high tensile modulus of 6.1 GPa.