Advanced biopolymer compounds for technical applications: Stereocomplex PLA with enhanced heat deflection temperature

Growing environmental awareness and independence from fossil raw materials are driving the popularity of biopolymers. Polylactide (PLA) is already one of the most popular biopolymers on the market due to its good processability and wide availability. However, due to its poor thermal stability, PLA is mainly used in low-performance applications. An important step towards using PLA for structural applications is to overcome its low heat deflection temperature. This can be achieved by stereocomplex (sc) crystallisation of the two enantiomers of PLA: PLLA and PDLA. However, exclusive sc crystallisation is difficult to achieve because of the accompanying homo crystallisation (α crystals), and the reported studies on sc-PLA have not exceeded the laboratory scale. This paper demonstrates the feasibility of pilot scale processing of pure sc-PLA and lays the foundation for the application of PLA as an engineering plastic.