Effect of Environmental Factors on Polylactide–Polybutylene Adipate Terephthalate Composites

Environmental factors, such as light, water, and temperature, have a combined impact on polymer materials. The present work considers the effect of ultraviolet radiation and distilled water on PLA/PBAT mixtures. It is found that as the content of PBAT in the PLA matrix is increased above 40 wt % the photodegradation of the material slows down. For example, after exposure to UV radiation with a wavelength of 254 nm for 100 h, the melting temperature of pure PLA decreases by 7°C, while that in the 70 PLA/30PBAT mixture decreases by 4°C. X-ray diffraction studies show that the crystalline phase of polylactide is destroyed after UV irradiation. The resulting PLA/PBAT materials undergo hydrolytic degradation, which is of importance for application in agriculture. In the composites close to phase inversion, the degree of water uptake increases.