The synthesis and characterization of thermotropic compounds for rim-type polymers.

Abstract

The Synthesis and Characterization of Thermotropic Compounds for RIM-Type Polymers (September 1982) Hiroshi Hoshino, B.S., Kyoto University, M.S., Kyoto University, M.S., University of Massachusetts Directed by: Professor R. W. Lenz Several hydroxy-terminated, low molecular weight polymers were reacted to form esters bearing mesogenic endgroups. The effect of the different repeating unit structures with a common mesogenic unit based on an oxybenzoylterephthalate dyad ester on the formation and properties of liquid crystals was studied by microscopic and thermal analysis techniques. The polymeric glycols used were polyethylene glycols (PEG), polytetramethyl ene glycols (PTMG), polybutadiene glycol (PB), and hydrogenated polybutadiene glycol (HPB) with molecular weight of 650 ^ 6000, in addition to 1 ,12-dodecanediol for the model compound. Conversion of the mesogenic dyad ester to a dyad containing a carboxylic acid group was shown to permit mesophase formation over a wide temperature range. The HPB product of this series was found to be a liquid crystalline elastomer with a low viscosity above the melting point, and with film forming ability. On examining the effect of endgroups on physical properties, it was found that both the length