Synthesis and Curing of Liquid-Crystalline Epoxy Resins Containing a Biphenyl Mesogen

✍ Scribed by Guodong Liu; Jungang Gao; Lili Song; Wenjun Hou; Liucheng Zhang

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 167 KB
• Volume: 207
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200600372

✦ Synopsis

Abstract

Summary: Liquid crystalline epoxies with a biphenyl mesogenic group have been widely studied although it is still in contention as to whether the diglycidyl ether of DGEBP shows a thermotropic phase. DEPBP was synthesized by partial oxidation and the liquid crystalline properties were investigated. Despite their similar structures their molecular weights are quite different. DEPBP has a distinct molecular weight, while DGEBP shows a molecular weight distribution. DEPEBP was also synthesized and characterized to investigate the influence of the flexible spacer. By incorporation of a flexible ethoxy group, the monomer shows no thermotropic property even in its curing reaction with an aromatic diamine, DDM. The curing rate was decelerated and the cured network showed a T~g~ even lower than that of cured DGEBA/DDM. The curing kinetics of DEPBP and DEPEBP were also tentatively investigated.

Arrhenius plot of DEPBP/DDM at α = 0.15.

magnified imageArrhenius plot of DEPBP/DDM at α = 0.15.