LIQUID-CRYSTALLINE POLYMER GELS .1. CROSS-LINKING OF POLY(GAMMA-BENZYL L-GLUTAMATE) IN THE CHOLESTERIC LIQUID-CRYSTALLINE STATE

Cross-linking of poly(γ-benzyl L-glutamate) in the cholesteric liquid-crystalline (CLC) state was carried out by using several diamines of different chain types as the cross-linkers in three different solvents. A PBLG/triethylenetetramine/dioxane mixture was found to be the best system, which upon heating at 70 °C for about 10 days gives a polymer gel, keeping the original cholesteric order. The cholesteric order disappeared when the gel was immersed in dichloroacetic acid, but the original CLC order was reproduced by immersing the gel again in dioxane. Therefore, the CLC structure was found to be memorized in the cross-linking networks. The reversible transition was induced also by the temperature change. © 1990, American Chemical Society. All rights reserved.