Physical blend of PLA/NR with co-continuous phase structure: Preparation, rheology property, mechanical properties and morphology

Polylactide (PLA), a thermoplastic polymers derived from biomass, was melt-blended with natural rubber (NR). Although without any interfacial modification, the brittle-ductile transition occurred at the blend with 35wt% NR, showing impact strength of about 500 J/m, approximately 7 times that of the neat PLA. Crystallinity study results indicated that the presence of NR did not obviously influence the crystallization of the PLA phase. Rheological study results showed that the viscosity of NR was much higher than that of PLA, facilitating the coalescence of the droplets of NR during blending. This, therefore, contributed to the formation of co-continuous phase structure of the PLA/NR blends. Interestingly, scanning electron microscopy studies further conformed the continuous phase of NR, showing a “network-like” continuous structure.