LC-polyimides 26. Photoreactive, nematic or cholesteric poly(ester-imide)s derived from 4-aminocinnamic acid trimellitimide, isosorbide and various diphenols
1995; SAGE Publishing; Volume: 7; Issue: 4 Linguagem: Inglês
10.1088/0954-0083/7/4/009
ISSN1361-6412
AutoresHans R. Kricheldorf, Nicolas Probst,
Tópico(s)Photopolymerization techniques and applications
ResumoA photoreactive and mesogenic dicarboxylic acid was prepared from 4-aminocinnamic acid and trimellitic anhydride. Its dichloride was polyeondensed with isosorbide and methylhydroquinone, phenylhydroquinone, 4,4'-dihydroxydilhenylether or 1.644'-dihy-droxyphenoxy)hexan. The copolyesters containing < 50 mol% of isosorbide form a cholesteric melt and the homopolyesters of the diphenols are nematie. WAXD powder patterns and DSC measurements agree in that all four homopoly(ester-imide)s are semicrystalline. Incorporation of isosorbide reduces and finally eliminates the crystallinity. The solid state of these copoly(ester-imide)s is a cholesteric glass. Copolyesters containing phenylhydroquinone and 5-10 mol% of isosorbide exhibit a Grandjean texture above 250C. The poly(ester-imide)s of unsubstituted diphenols undergo thermal cross-linking above 350C and all poly(ester-imide)s are sensitive to photocross-linking upon irradiation at wavelengths <360 nm.
Referência(s)