Polymeric liquid crystals: Cholesteric superstructure from blends of hydroxypropylcellulose esters

n-Butyric, iso-butyric, n-valeric and iso-valeric esters Of hydroxypropylcellulose were synthesized. Their behaviors, in terms of cholesteric structure, glass (T-g) and anisotropic-isotropic (T-i) transition temperatures are compared to results in the literature. A 6-8 month time period from sample preparation has no influence on the cholesteric phase characteristics. Six binary blends may be formed from the four esters. They show only a T-g value at each composition, which suggests a good miscibility among the components. However, positive deviation of linearity of T-g vs. composition varies from one pair to another. Analysis of the absorption curves in UV-vis spectra shou? that three pairs form a single cholesteric helix containing both components while other three give a only nematic phase. Colors changing from red to violet are shown for blends of n-butyric and iso-butyric esters at different weight ratio. Copyright (C) 2003 John Wiley Sons, Ltd.