Synthesis of starch-g-poly(glycidyl methacrylate) and its blending with poly(ε-caprolactone) and nylon 610

Different amounts of glycidyl methacrylate (GMA) were grafted onto corn starch dispersed in water or dimethyl sulfoxide (DMSO) to yield starch-graft-poly(glycidyl methaerylate) (ST-g-PGMA). ST-g-PGMAW, obtained by grafting PGMA onto corn starch that was dispersed in water, showed a higher PGMA grafting content and a lower content of the homopolymerized PGMA than ST-g-PGMAD, which was prepared in DMSO. The modified starches were blended with poly(epsilon-caprolactone) (PCL) and nylon 610, respectively, and the tensile properties of the blends were measured by UTM. Mechanical properties of the biodegradable ST-g-PGMA/PCL blends were dependent on the PGMAD content grafted on starch. Without dramatic loss of the tensile properties of PCL, ST-g-PGMAW was melt blended with PCL. Meanwhile, an increase in the tensile modulus was observed in the ST-g-PGMAW/nylon 610 blend. When nylon 610 was reacted with ST-g-PGMAW in DMSO in the presence of triethylamine, the tensile modulus and strength were much higher than those of the pure nylon 610, and phase-separated domains of starch were not observed microscopically.