| Abstract: | (S)-Pentyloxyterephthalic acid was prepared by alkylation of dimethyl trimethylsiloxyterephthalate with (S)-2-methylbutan-1-ol 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. 2-(4'-Chlorophenoxy)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. © 1996 John Wiley & Sons, Inc. |
