Biodegradable and Bio-based Green Blends from Carbon Dioxide-Derived Bioplastic and Poly(Butylene Succinate)

Conventional polymer materials from fossil fuels feature many unresolved questions regarding disposing and future resource availability. To substitute some of the established plastics with bio-based and biodegradable alternatives, new materials have to be developed and researched. The aliphatic biodegradable polyester poly(butylene succinate) offers good material properties and the perspective to be partially bio-based in the future. Poly(propylene carbonate) is an amorphous co-polymer of propylene oxide and carbon dioxide. The incorporation of carbon dioxide in the polymer offers a great way to reduce the excess CO₂ levels in the atmosphere and at the same time to add a bio-based component to the plastic. By melt blending and injection molding these two materials, partially bio-based, potentially biodegradable blends are generated. The blends’ mechanical, thermal and morphological properties are studied, using DSC, DMA, TMA, SEM, and FTIR analysis as well as tests regarding impact, flexural and tensile properties. Furthermore, the shrinkage of PPC, PBS and their blends is examined. It was found that blending of these two materials, without any additives or fillers, is not very promising, as almost all mechanical and thermal properties are decreased compared to the neat PBS. However, shrinkage of PPC can be eliminated when added into a PBS matrix and low contents of PPC might offer a possibility to increase the impact toughness of PBS.