INFLUENCE OF MOLECULAR-WEIGHT ON THE RESISTANCE OF POLYLACTIDE FIBERS BY RADIATION STERILIZATION

The mechanical properties and in vitro degradability of poly(L-lactide) fibers with different average molecular weights, prepared by a dry spinning-hot drawing process from CHCl3 solutions, were studied in relation to the gamma-irradiation dose. In the range of molecular weight of 1.6-3.6 X 10(5), no differences were found in the relative decrease of tensile strength after irradiation of 25 kGy. Changes of the elongation at break are discussed in terms of a network solution theory. In vitro degradation of the fibers is also discussed in network solution theory terms. Regardless of the courses of degradation curves, it may be stated that all prepared fibers could be sterilized by gamma-rays and the rate of degradation was not affected by the irradiation dose. (C) 1993 John Wiley & Sons, Inc.