Superheat-resistant polyimides with ultra-low coefficients of thermal expansion. (20th May 2020)

• Record Type: Journal Article
• Authors: Qian, Guangtao; Chen, Haiquan; Song, Guangliang; Dai, Fengna; Chen, Chunhai; Yao, Jianan
• Is Part Of: Polymer. Volume 196(2020)
• Publication Date: 2020-05-20
• Subjects: Poly(benzimidazole imide) -- N-methyl -- Ultra-low CTE; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2020.122482
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: To achieve the superheat-resistant polymers for flexible display substrates, two new diamines, namely 6-amine-2-(4-aminobenzene)-1-methyl-benzimidazole ( m -MePABZ), 5-amine-2-(4-amino-benzene)-1-methyl-benzimidazole ( p -MePABZ) containing N-methyl benzimidazole (BI) were synthesized and a serials of poly(benzimidazole imide) (PBII) films were prepared through thermal imidization. Among them, the flexible polyimide (PI) film derived from m -MePABZ and pyromellitic dianhydride (PMDA) has an ultra-low coefficient of thermal expansion (CTE) down to 2.5 ppm K −1 and an outstanding high glass-transition temperature (Tg ) up to 431 °C. Furthermore, the employment of N-methyl overcame an issue of the high H2 O-absorption of traditional PBIIs, and the effect of " para -" and " meta- connecting" methyl on molecular packing and properties of these PIs was investigated. These data provided a useful guide to develop high performance PBIIs by incorporating N-methyl. Graphical abstract: Image 1 Highlights: Two novel diamines ( m -MePABZ and p -MePABZ) were successfully synthesized. The effect of " para -" and " meta- connecting" methyl on molecular packing and properties of these PBIIs was investigated. m -MePABZ-PMDA film illustrated an ultra-low CTE of 2.5 ppm K -1 and an extremely high Tg of 431 °C.