Fabrication, mechanical and electrical properties of polyimide films cured at low-temperature assisted by microwave radiation. (November 2022)

• Record Type: Journal Article
• Authors: Tao, Kangkang; Qin, Fei; Li, Yahui; Zhang, Shuai; Han, Shihui; Liu, Guangmin; Wang, Jun; Shen, Jun; Yang, Zailin; Tang, Yi; Sun, Gaohui
• Is Part Of: High performance polymers. Volume 34:Number 9(2022)
• Page Start: 998
• Page End: 1008
• Publication Date: 2022-11
• Subjects: Polyimide films -- low-temperature -- microwave -- mechanical and electrical properties; Polymerization -- Periodicals; Polymers -- Periodicals; 547.7
• DOI: 10.1177/09540083221100366
• Languages: English
• ISSNs: 0954-0083

Abstract

Polyimide (PI) films with excellent mechanical and electrical properties were produced at a low temperature assisted by microwave. Depending on the reciprocating movement of dipole molecules excited by microwave, even though under a low temperature, the rotation and conformational changes of functional groups could also be promoted. Thus, reaction between N-H bond and -OH in carboxyl which could realize dehydration and cyclization of polyamic acid proceeded normally. Results revealed that the combination between ambient temperature only at 70°C and microwave power at 2000 W or higher could also produce PI films with imidization degree of 100%. For PI-2000W, compared with traditional PI film (PI-300°C) that generated only at temperature of 300°C, even though on the basis of no any change in molecular structure and addition of filler, the tensile strength, elastic modulus, crystallinity, and apparent density increased by about 21%, 51%, 37%, and 5%, respectively. For electrical properties, conductivity enhanced by one to two orders of magnitude comparing with PI-300°C. Results indicated that while keeping the original molecular structure of PI films unchanged, this work provided a new and effective method to assist the enhancement in mechanical and electrical properties of PI films.