Effect of Nano-Clay and Surfactant on the Biodegradation of Poly(Lactic Acid) Films

This study examined the effect of nanoclays and surfactant on the hydrolytic degradation and biodegradation of poly(lactic acid) (PLA) and PLA nanocomposites. Organomodified montmorillonite (OMMT), unmodified montmorillonite (MMT) and an organomodifier (surfactant) for MMT (QAC) were extruded with PLA to produce PLA nanocomposites. The films were produced with the same initial molecular weight, thickness and crystallinity since these properties have a significant effect on the biodegradation process. The biodegradation experiments were carried out in an in-house built direct measurement respirometric system and were evaluated in inoculated vermiculite and vermiculite media for extended periods of time. Hydrolysis experiments were also conducted separately to decouple the abiotic/hydrolysis phase. The results showed no significant variation in the mineralization of PLA nanocomposites as compared to pristine PLA. The addition of nanoclays did not enhance the biodegradability of PLA when the initial parameters were strictly controlled. The hydrolysis test indicated that the nanoclays and surfactant did not aid in the degradation of PLA.