The effects of cross-linked starch on the properties of thermoplastic starch

In order to improve the poor tensile properties and high water absorption of thermoplastic starch (TPS), cross-linked starch was added into the TPS matrix. The cross-linked starch contents ranged from 0 wt% to 20 wt%. The TPS/cross-linked starch composites were analyzed for the morphology of their fractured surfaces, the thermal decomposition temperatures, ability to absorb water and mechanical properties. The results showed that the incorporation of cross-linked starch into the TPS matrix caused considerable improvement to tensile strength. The maximum tensile strength was obtained with addition of 20 wt% cross-linked starch. Moreover, water absorption of the TPS samples was clearly reduced by the inclusion of cross-linked starch. The thermal degradation temperatures of the composites were also higher than those of the TPS matrix.

► Thermoplastic starch/cross-linked starch composites were prepared using compression molding. ► The tensile strength increased as the amount of the cross-linked starch increased. ► The thermal degradation temperatures of the composites were higher than for TPS. ► The cross-linked starch can decrease the water absorption of TPS.