The Influence of Secondary Polymer Raw Materials on the Structure and Properties of Polyethylene–Polylactide Mixtures in the Photodegradation Process

Due to human activity and the limitations of recycling technology, a huge amount of plastic products penetrate into the environment, where they accumulate because of their long destruction period. Currently, there is a focus on sustainable development of new environmentally friendly technologies, in which secondary polymers, the use of which is considered as a solution to the environmental problem, are of particular interest. It was found that, when oxidized polyethylene (an analogue of secondary polyethylene and polylactide) is added to a PLA/LDPE mixture, the morphology and thermophysical properties of the mixture change and the photodegradation process accelerates. It was established that polylactide and the oxidized polyethylene in the mixture contribute to the accelerated destruction of samples, cracking of the sample surface, and a decrease in the melting point and degree of crystallinity of polylactide and polyethylene under UV radiation with a 254-nm wavelength for 100 h.