Poly(lactic acid)/acetylated starch blends: Effect of starch acetylation on the material properties.

This study investigated the acetylation of starch to improve its processability and compatibility with poly(lactic acid). The temperature at the maximum rate of degradation increased by 3.2% for poly(lactic acid) blends containing acetylated starch degree of substitution 2.5 compared to the blend containing neat starch. A biphasic morphology with distinct dispersed phase was predicted and observed experimentally for all blends except the blend containing acetylated starch degree of substitution 3. Acetylated starch induced plasticization and nucleation for all degree of substitution. The blend containing acetylated starch degree of substitution 2.5 had higher tensile strength (26%), and toughness (29%) compared to the blend containing neat starch. The superior mechanical properties of the blend containing acetylated starch degree of substitution 2.5 are attractive for medical implant applications. The continuous microstructure and transparency characteristics of the blend containing acetylated starch degree of substitution 3 are attractive for packaging applications.