HISTORY DEPENDENCE OF STRESS COUPLED TRANSPORT IN POLYMER FIBERS AND RIBBONS.

A recently developed technique overcomes the inability of traditional methods to measure stress or deformation interactively with diffusion. In addition, this technique is able to make concurrent swelling and elastic modulus estimations while measuring the linear mass density of stretched linear samples. Measurements of the 'vibrational time delay' of transverse wave pulses travelling down the length of a stretched fiber or ribbon are made. The well known result for transverse vibrations in a stretched string, that the velocity of travel of the transverse wave is proportional to the square root of the ratio of the tension and linear mass density of the sample, has been found to hold true for this system. This result is used to estimate the mass per unit length of the sample. Typical results of experiments are shown for polycarbonate and polyethermide ribbons.