ADHESION OF POLYSULFONE-LIQUID CRYSTALLINE POLYMER BLENDS TO FIBERS

The effect of modifying a thermostable thermoplastic matrix with a liq uid-crystalline (LC) polymer on its adhesion to fibers was investigate d. Poly(arylene sulfone), LC polyether, and blends of them of varying composition were used as the matrices, and high-strength steel wire 15 0 mu m in diameter and alkali-free glass fibers 150-300 mu m in diamet er were the substrates. The adhesive shear strength tau, measured by t he pull-out method, was used as the measure of adhesion. The samples w ere formed at a temperature of T-f = 300 degrees C, and the heat treat ment time t(f) varied from 15 min to 2 h. It was found that when the v alues of t(f) increased, the dependence tau-t(f) was described by a cu rve with a maximum. The maximum was observed for t(f) = 30 min. The ad hesive strength at the bonds of the poly (arylene sulfone) with the st eel 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 blend; in bo nds with the steel wire was much higher than in bonds with the glass f iber. The adhesive strength of the blends as a function of the concent ration of LC polyether was described by a curve with a maximum. The ma ximum adhesive strength with fibers was provided by matrices containin g 2-7% LC polyether.