Biodegradation assessment of PLA and its nanocomposites

Poly(lactic acid) nanocomposites containing Cloisite 15A, Cloisite 30B, and Dellite 43B were prepared by melt-mixing in a batch mixer and were exposed to UV radiation, temperature, and microorganism in solution and in a compost. Exposed samples, collected along the time, were characterized by several techniques. While the addition of organoclays had a positive effect on thermal stability, the degradation rate of nanocomposites increased when exposed to UV radiation and microorganism. Moreover, the degradation rate depends on the organoclay type. Even though the degradation rate is higher for nanocomposites, Fourier transform infrared spectrometry and gel permeation chromatography results demonstrated that the degradation mechanism is the same.