Shaw H. Chen, J. Mastrangelo, Hongqin Shi
Nov 1, 1995
Citations
0
Influential Citations
33
Citations
Journal
Macromolecules
Abstract
Adamantane was employed as an excluded-volume core for the synthesis of two- and four-arm liquid crystalline, as well as amorphous, molecular systems capable of vitrification upon thermal quenching. It was found that (-)-cholesterol as the side arm exhibited a smectic A and a cholesteric mesophase, whereas 1-phenyl-2-(6-cyanonaphth-2-yl)ethyne and cyanotolan showed a nematic mesophase in both two- and four-arm systems. Furthermore, disperse red 1 resulted in amorphous, nonmesogenic materials. In general, the four-arm systems tend to elevate T g and T c and to depress recrystallization of the quenched glass upon heating in comparison to the two-arm systems. It was also found that with 1-phenyl-2-(6-cyanonaphth-2-yl)ethyne, the four-arm adamantane showed an elevated T g but a somewhat depressed T c relative to the three-arm cyclohexane counterpart.