Liquid crystalline epoxy resin based on biphenyl mesogen: Effect of magnetic field orientation during cure

TitleLiquid crystalline epoxy resin based on biphenyl mesogen: Effect of magnetic field orientation during cure
Publication TypeJournal Article
Year of Publication2013
AuthorsLi YZ, Kessler MR
Journal TitlePolymer
Volume54
Pages5741-5746
Date Published10
Type of ArticleArticle
ISBN Number0032-3861
Accession NumberWOS:000326204200036
Keywordsac electric-fields, curing kinetics, Liquid crystalline epoxy resins (LCERs), Magnetic field orientation, mechanical-properties, monomers, networks, photopolymerization, polydomain, polymer-films, rigid-rod, Thermomechanical properties, thermosets
Abstract

A biphenyl based epoxy monomer, 4,4'-diglycidyloxybiphenyl (BP), was synthesized and cured with a tetra-functional amine, sulfanilamide (SAA), to obtain a liquid crystalline epoxy network. The curing behavior of BP with SAA was studied using differential scanning calorimetry, polarized optical microscopy, and parallel plate rheology. Macroscopic orientation of the liquid crystalline epoxy resins (LCERs) was achieved by curing in a high strength magnetic field, and quantified by an orientation parameter determined with wide angle X-ray diffraction. The effects of orientation on the glass transition temperature, coefficient of thermal expansion, and dynamic mechanical properties of the LCERs were investigated. The results reveal that the formation of the liquid crystalline phase has a dramatic influence on the curing reaction, leading to a decrease in viscosity of the reacting system. Oriented LCERs exhibit anisotropic thermal expansion behavior and significant improvements of thermomechanical properties. (C) 2013 Elsevier Ltd. All rights reserved.

URL<Go to ISI>://WOS:000326204200036
DOI10.1016/j.polymer.2013.08.005