Effect of the elongation rate on the biodegradation of oriented polycaprolactone films by a pure strain of micro-organisms isolated from an industrial compost for house-hold refuse

It has been demonstrated that unidirectional orientation of semi-crystallin e polycaprolactone (PCL) films strongly affects their degradation behaviour in the presence of micro-organisms. For films of the same final thickness (300 mu m), elongated using strain rates between 1.6 and 0.02 min(-1), the rate of oxygen consumption is similar for all samples during the first 200 h of degradation. After that time the rate becomes strongly dependent on th e elongation conditions. After 700 h of incubation, the weight loss is 99 a nd 25% for samples obtained with strain rates of 1.6 and 0.02 min(-1) respe ctively. When compared with the non-orientated sample, the 1.6 min(-1) samp le degrades faster while the others degrade more slowly. The results are di scussed in terms of models proposed in the literature for oriented films.