Stress-Relaxation and Vibrational Properties of Some Fibrous Polymers at Various Conditions of Temperature and Relative Humidity

Abstract

Stress-relaxation curves, dynamic Young's modulus, and dynamic internal friction have been obtained for single filaments of rayon, nylon, and polyethylene at 2° and 25° C. and at several relative humidities. Stress-relaxation measurements have been taken at 0.02 sec. after elongation. Dynamic parameters were observed in a forced longitudinal vibration experiment in which the vibrational frequency could be varied from approxi mately 5 to 50 cps. It is found that the dissipation of energy per cycle of vibration (measured by ηω) increases with increasing relative humidity, but that the slope of the stress-relaxation curve decreases with increasing relative humidity. An indication is given that energy dissipation in viscose rayon is independent of hydrogen bonding in the material.