Adhesion of polysulfone—Liquid crystalline polymer blends to fibers

Abstract

The effect of modifying a thermostable thermoplastic matrix with a liquid-crystalline (LC) polymer on its adhesion to fibers was investigated. Poly(arylene sulfone), LC polyether, and blends of them of varying composition were used as the matrices, and high-strength steel wire 150 μm in diameter and alkali-free glass fibers 150–300 μm in diameter were the substrates. The adhesive shear strength τ, measured by the pull-out method, was used as the measure of adhesion. The samples were formed at a temperature of Tf=300°C, and the heat treatment time tf varied from 15 min to 2 h. It was found that when the values of tf increased, the dependence τ−tf was described by a curve with a maximum. The maximum was observed for tf=30 min. The adhesive strength at the bonds of the poly(arylene sulfone) with the steel wire was sufficiently high (comparable to the adhesive strength of epoxy—4,4′-isopropylidenediphenol matrices). The adhesive strength of the LC polyether with the steel wire was much lower. The strength of the interface of poly(arylene sulfone), LC polyether, and blends in bonds with the steel wire was much higher than in bonds with the glass fiber. The adhesive strength of the blends as a function of the concentration of LC polyether was described by a curve with a maximum. The maximum adhesive strength with fibers was provided by matrices containing 2–7% LC polyether.