Improving the compatibility and toughness of sustainable polylactide/poly(butylene adipate-co-terephthalate) blends by incorporation of peroxide and diacrylate

Abstract

Polylactide/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends were compatibilized using dicumyl peroxide (DCP) and poly(ethylene glycol) 600 diacrylate (PEG600DA) through a one-step melt-blending process. The compatibility and performance of these blends were subsequently characterized. The results showed that grafts formed “in situ” effectively improved the compatibility and interfacial adhesion between PLA and PBAT phases. Melt viscosity and elasticity of both the PLA/PBAT/DCP and PLA/PBAT/DCP/PEG600DA blends evinced significant increases. Compared to PLA alone, both cold and melt crystallization abilities of the PLA/PBAT/DCP/PEG600DA blends were enhanced, with crystallinities increasing by 5 % - 10 %. Furthermore, the thermal stability, as well as hydrophobicity and oleophobicity of the compatibilized blends improved. In comparison with PLA, the elongation at break and notched impact strength for the PLA/PBAT/DCP/PEG600DA (60/40/0.1/4) blend achieved increases of 290 % and 44.23 kJ/m2, corresponding to improvements of 279 % and 1457 %, respectively. The toughening effect was substantially influenced by the ductile matrix (either a co-continuous phase or a flexible PBAT matrix) in addition to the strong interfacial adhesion and fine phase domain. These eco-friendly blends exhibit considerable potential for packaging articles and 3D printing products owing to their excellent mechanical properties and enhanced melt rheology.