Poly(L-lactic acid)/poly(butylene succinate) biobased biodegradable blends

Poly(L-lactic acid) (PLLA) and poly(butylene succinate) (PBS) are biodegradable, compostable, and biocompatible polymers that can be produced from annually renewable resources. These properties made them popular in environmentally friendly applications, and their industrial usage and production have grown in the latest years. However, both polymers have a few drawbacks that have limited so far their use: PLLA is hard and brittle with a slow crystallization rate, whereas PBS is ductile, has fast crystallization kinetics, but low modulus. The complementarity of their properties makes their blending a unique opportunity to exploit the favorable properties of the two polymers, which raised considerable research efforts in recent years on blends made of PLLA and PBS. Unfortunately, literature data on PLLA/PBS blends often report contradictory results on miscibility of the two polymers, as well as on the influence of composition on material properties: this creates confusion, complicating their exploitation. As an effort to elucidate miscibility and properties of the blends as function of composition, a critical analysis of the available research results on blends made of PLLA and PBS is provided in this review. The aim is to highlight the potentiality of PLLA/PBS blends, whose properties can be tailored by fine-tuning the composition.