LC polyimides. XXVII. Cholesteric poly(ester-imide)s derived from chiral i-pentyloxyterephthalic acids

✍ Scribed by Hans R. Kricheldorf; Dirk F. Wulff

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 514 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199612)34:17<3511::aid-pola5>3.0.co;2-x

✦ Synopsis

Pentyloxyterephthalic acid was prepared by alkylation of dimethyl trimethylsiloxyterephthalate with (S)-2-methylbutan-l-o1 tosylate. (S,S)-2,5-bis-i-pentyloxyterephthalic acid was prepared analogously by alkylation of diethyl-2,5-bis(trimethylsiloxy)terephthalate. A series of cholesteric poly(ester-imide)s was synthesized from (S)-pentyloxyterephthalic acid and N-(4'-hydroxyphenyl)-4-hydroxyphthalimide. 234)terephthalic acid was used as comonomer. The 1 : 1 copolyester of both terephthalic acids forms a Grandjean texture in the shearing of the cholesteric melt. A second series of cholesteric poly(ester-imide)s was prepared from (S,S)-2,5-bispentyloxyterephthalic acid and the aforementioned imide diphenol. In this case 2,5-bis(dodecyloxy)terephthalic acid was used as comonomer to lower the melting point. The cholesteric phases of the resulting copoly(ester-imide)s did not form a Grandjean texture.