SYNTHESIS AND CHARACTERIZATION OF STARCH-GRAFT-POLYCAPROLACTONE AS COMPATIBILIZER FOR STARCH POLYCAPROLACTONE BLENDS/

Polycaprolactone (PCL) was grafted onto starch through introduction of urethane linkages. The grafting reaction was carried out in two steps . The first step was the reaction of hydroxyl-terminated PCL with 2,4- tolylene diisocyanate. The isocyanate terminated PCL was then reacted with starch to obtain starch-graft-polycaprolactone (starch-g-PCL). Th e grafting reaction was confirmed by FT-IR spectroscopy. The compatibi lity of the starch/PCL blend was enhanced with a compatibilizer, starc h-g-PCL, whose amount was 3 wt.-% of the blend. The tensile strength a nd morphology of the compatibilized blend were determined. It was foun d that the compatibilized starch/PCL blend has finer phase domains and an improved interfacial adhesion. Mechanical properties of the compat ibilized blend were found to be significantly higher than those of the corresponding uncompatibilized starch/PCL blend.