Improvement of rheological and mechanical properties of PLA by reactive blending with Poly(MMA-g-GMA)

The aim of this study is to improve the melt strength of Polylacticacid (PLA) using methylmethacrylate-g-glycidylmethacrylate copolymers, Poly(MMA-g-GMA), that was synthesized by reactive blending at different weight fractions of GMA from ۶ to ۱۰%. Copolymers were blended with polylacticacid (PLA) in internal mixer at different weight fractions including ۰, ۶ and ۸% as chain extender to modify the rheological behavior. Properties of neat PLA and modified PLA were characterized by Differential Scanning Calorimetry (DSC) and Rheometric Mechanical Spectrometer (RMS). The balanced torque was increased by increasing the fraction of copolymer chain extender. The glass transition temperature of PLA was also changed by blending with the synthesized copolymer. The blending affected the cold crystallization behavior and melting behavior of PLA, as well. Dynamic moduli also showed higher viscosities that can lead to higher melt strength. Generally speaking, our results showed that Poly(MMA-g-GMA) is an effective chain extender for PLA.