Mesogens biphenyl-based

Properties have been determined for a series of block copolymers based on poly[3,3-bis(ethoxymethyl)oxetane] and poly [3,3-bis(methoxymethyl)oxetane]- (9-tetrahydrofuran. The block copolymers had properties suggestive of a thermoplastic elastomer (308). POX was a good main chain for a weU-developed smectic Hquid crystalline state when cyano- or fluorine-substituted biphenyls were used as mesogenic groups attached through a four-methylene spacer (309,310). Other side-chain Hquid crystalline polyoxetanes were observed with a spacer-separated azo moiety (311) and with laterally attached mesogenic groups (312). 

In a very recent publication Thomas and coworkers used the same principle with a custom-synthesized mesogen (LC) based on an imidazole head-group and a rigid biphenyl core with, however, a ten- and eight-carbon... 

Several vinyl ether comonomers based on the same biphenyl mesogen with different spacers and/or different substituents were also copolymerized using the same conditions (Eq. 36). All of the copolymerizations were assumed to be azetropic (ri=r2=l), and most were based on copolymer pairs containing at least three carbons in the spacer. Although the copolymers prepared by cationic polymerizations were not of... 

Percec V, Heck J (1991) Liquid crystalline polymers containing mesogenic units based on half-dise and rod-Uke moieties. I. Synthesis and characterization of 4-(l 1-undecan-1-yloxy)-4-[3,4,5-tri(p-n-dodecan-l-yloxybenzyloxy)benzoate]biphenyl side groups. J Polym Sci A PolymChem 29(4) 591-597. doi 10.1002 1a.l991.080290416... 

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