Monodisperse "rodcoil" copolymers

Abstract

Objective here has been to initiate experimental work on the phase and scaling behavior of rod-coil systems. In this paper the authors report on the synthesis and preliminary characterization of the first monodisperse rodcoil copolymer in which both rod and coil segments are part of the molecular backbone. A representation is shown by molecular graphics of an energy-minimized conformation of their rodcoil polymer. Also the rodlike segment when detached from the coil exhibits liquid crystalline behavior demonstrating the stiff segment's high aspect ratio in a condensed phase. The thermotropic behavior of the rod component may lead to the formation of various mesophases with changing temperature, and the long-range order may be influenced by external fields. The coils may also act to isolate liquid crystalline domains into discrete monolayers, forming nanoscale liquid crystals. As far as they know the only work reported so far involves side-chain liquid crystalline polymers coupled to polystyrene and poly(methyl methacrylate), but here the rod and coil components are not part of the same molecular backbone. Therefore, these systems lack an abrupt change in backbone rigidity along the chain's contour length.