Crystallization, rheology and foam morphology of branched PLA prepared by novel type of chain extender

Improving the melt strength of polylactide (PLA) is of continuing strategic research highlight, since this property affects the foaming processability. Using a novel type chain extender, namely polystyrene/poly(glycidyl methacrylate) random copolymer, PLA is branched through melt compounding. Comparing to the neat PLA, the new branched products characterize significantly improved complex viscosity as well as elongational viscosity shown from rheological experiments. Furthermore, differential scanning calorimetry analysis (DSC) indicates the branched structure could also hinder cold crystallization. Owing to the improved viscous and elastic properties, the foams of branched PLA exhibits smaller cell size and higher density, when we use supercritical carbon dioxide (Sc-CO2) as the physical foaming agent. Open image in new window