Thermal and mechanical properties of biodegradable composites of poly(propylene carbonate) and starch–poly(methyl acrylate) graft copolymer

Starch–g-poly(methyl acrylate) (S–g-PMA) copolymer was prepared by ceric ammonium nitrate-initiated polymerization of methyl acrylate onto corn starch (CS). Our analyses, including FTIR, DSC and TGA measurements confirmed the successful grafting of PMA onto starch and the grafting percentage of the copolymer was calculated. The S–g-PMA was subsequently mixed with biodegradable poly(propylene carbonate) (PPC) at various proportions in a batch mixer. The morphology, mechanical properties, as well as thermal properties of PPC/S–g-PMA composites were investigated. Tensile tests showed that the S–g-PMA incorporation improved the stiffness and tensile strength of composites significantly. Experimental results indicated that the S–g-PMA addition led to an improvement in the thermal stability of resulting composites. Moreover, the PPC/S–g-PMA composites showed greater elongation and better phase adhesion between PPC matrix and reinforcements than PPC/CS composite without S–g-PMA.