Biodegradation of LDPE_TPS blends under controlled composting conditions

Plastic waste can serve as a symbolic expression of environmental pollution because of its prevalence and extremely slow degradation. A well-known example of synthetic plastics is low-density polyethylene (LDPE). A pragmatic approach to mitigate the environmental problems is to develop biodegradable plastic without compromising the quality of properties or increasing the price. To meet these requirements, one must turn to polymers from natural sources, such as starch. Starch is a fully biodegradable, semi-crystalline, non-toxic polymer with difficulties in processing. To obtain thermoplastic starch (TPS), a biodegradable glycerol plasticizer and sheer processing are necessary over a so-called gelatinization. Here, we aim to prepare and investigate sustainable and environmentally friendly packaging materials based on biodegradable blends, such as LDPE_TPS. The prepared blends were subjected to extensive physicochemical characterization to clarify the functional performance and biodegradability. Changes in structure, morphology and chemical composition before and after biodegradation were interpreted and correlated. Problems such as high interfacial tension due to high incompatibility between the non-polar polyolefin and the highly polar TPS were alleviated for some blends. The observation of mechanical, diffusive and composting parameters suggests that the modifier plays a crucial role in obtaining homogeneous polymer blends. The study of LDPE_TPS blends shows that it is possible to produce polymer blends with good biodegradability and balanced mechanical performance at a reasonable price.

Automated summary

Plastic waste is a symbolic expression of environmental pollution, and developing biodegradable plastics is a pragmatic approach to mitigate environmental problems. Starch, as a fully biodegradable polymer, is difficult to process. This study aims to prepare sustainable and environmentally friendly packaging materials based on biodegradable blends, and concludes that modifiers play a crucial role in obtaining homogeneous polymer blends.