International Union of Pure and Applied Chemistry Macromolecular Division Commission on Polymer Characterization and Properties Working Party on Structure and Properties of Commercial Polymers* Studies on Biodegradable Poly(hexano-6- Lactone) Fibers. Part 2: Environmental Degradation

Poly(hexano-6-lactone) (PCL2) ®bers were degraded under environmental conditions, including soil burial, seawater exposure, and activated sludge exposure. The extent of degradation was examined by weight loss, loss of mechanical properties, such a tensile strength and ultimate elongation decreases, and visual observations by scanning electron microscopy. The rate of degradation was found to depend on the draw ratio and crystallinity of the PCL ®bers with surface erosion of amorphous regions more readily than crystalline regions. The life-time of highly drawn PCL ®bers when exposed to soil burial and seawater was evaluated from the viewpoint of environmental applications. In terms of the degradation mechanism of PCL ®ber breakdown, biodegradation seems to be the dominant reaction, that is a hydrolysis reaction catalyzed by enzymes secreted by microorganisms.