Effect of Octenyl Succinate Starch on Properties of Tapioca Thermoplastic Starch Blends

摘要

Water resistant is drawback property of thermoplastic starch. Blending of hydrophobic starch to natural one is another solution. Different blending ratio of tapioca/octenyl succinate starch (OSA) at 0/100, 25/75, 50/50, 75/25, 100/0 were prepared using internal mixer, and molded by compression molding at 135-140°C, 1000-1500 MPa for 9 minutes. Density of the blend was decreased, due to lower density of OSA starch. There was mechanical properties improvement in 25% OSA blended tapioca starch i.e. tensile strength, Young's modulus & elongation at break, due to synergy effect of OSA & tapioca starch. There was improvement in degradation temperature of the blend studying by TGA technique. Water resistance of the blend is improved related to the content of OSA starch in the blend on short time contact (10 min), but no impact at longer time exposure (lhr). The blend had a better resistant to degradation with a-amylase, which OSA starch could retard the degradation.