Studies on Tensile Strength, Heat-Shrinkage Force, and Crystallinity of Rayon Tire Cords and Regenerated Cellulose Films at Elevated Temperatures

Abstract

Measurements were made of tensile strength and heat-shrinkage force of rayon tire cords and of ir absorption spectra (unpolarized and polarized) of regenerated cellulose films in D2O vapor at elevated temperatures. The changes in crystallinity and frequency of OH absorption bands (intermolecular and intramolecular hydrogen bonding) in the crystalline region with increasing temperatures were determined. The ir absorption spectra of dry, regenerated cellulose films were also measured. The decrease in intermolecular hydrogen-bonding force with increasing temperatures was larger than that in intramolecular hydrogen-bonding force in the crystalline region of regenerated cellulose film. The increase in heat-shrinkage force of dry, rayon tire-cord filaments was related with the decrease in hydrogen bonding force. The decrease in tensile strength of rayon tire cord was correlated with the decrease of ir crystallinity and intermolecular hydrogen-bonding force in the crystalline region of regenerated cellulose film.