Biodegradation and hydrolysis studies on polypropylene/polylactide/organo-clay nanocomposites

Polypropylene/Poly(lactic acid) (PP/PLA) nanocomposites based on organically modified montmorillonites at 5 wt% loading were prepared by melt blending using a co-rotating twin-screw extruder. Degradation of compression-molded thin films of the nanocomposites was investigated in compost by infrared spectroscopy (IR), optical microscopy (OM) and weight loss measurements. The differential scanning calorimetry (DSC) was found to be a suitable method for study of the effect of hydrolysis of the samples in acidic or basic solutions. The IR and OM studies of the samples buried under compost for 12 months confirmed the biodegradation phenomena. Moreover, a good correlation was established between the degrees of crystallinity and hydrolysis extent. These studies showed that the addition of nanoclays can increase the PLA degradation. Microbial degradation by Aspergillus niger fungi incubated using a nutrient media in an incubator for 1 month showed a weight reduction of 0.3-0.5 % during such a short period of microbial degradation.