Effect of Chain Extension on the Rheological Property and Thermal Behaviour of Poly(lactic acid) Foams

Epoxy-based chain extended high-melt-strength poly (lactic acid) (PLA) was prepared. Rheological properties and the thermal behaviours of the chain extended PLA were studied. The rheological properties indicated that the melt elasticity and melt strength of the chain extended PLA samples were gradually improved by increasing the content of chain extender (CE). Moreover, the thermal results showed that the crystallinity and the spheruilite morphology of PLA were greatly influenced due to the introduction of CE The effect of CE contents on foam morphology was also studied. Adding CE resulted in higher expansion ratio and smaller cell size of PLA foams.