Polymer, Vol.158, 59-64, 2018
Unfrustration of a frustrated liquid crystalline polymer
4,4'-biphenyl dicarboxylate modified poly(ethylene terephthalate) (PET) copolyester molecules proximate to glass fiber surfaces in composites are shown to self-order into a liquid crystalline state. Near the glass fiber surfaces, the polymer chains are proposed to align and form more ordered domains increasing translational entropy, which leads to an overall increase in entropy of the system. The frustrated liquid crystalline polymer of this study, when confined near glass fiber surfaces, became more easily ordered, an example of the concept know as "order through entropy". Solid-phase birefringence, lower molten-phase viscosity and storage modulus were observed and discussed as properties of these new systems. Such glass fiber reinforced PETBB55 composites possess enhanced mechanical and processing properties, a unique combination.