Mechanical properties of biodegradable polylactide/poly(ether-block-amide)/thermoplastic starch blends: Effect of the crosslinking of starch

Corn starch was crosslinked with epichlorohydrin (ECH) and then plasticized with glycerol. Subsequently, this thermoplasticized crosslinked starch (TPCLS) was melt-compounded with polylactide (PLA) and poly(ether-block-amide) (PEBA) to prepare biodegradable PLA/PEBA/TPCLS blend with high impact resistance. It was found that the crosslinking agent ECH had critical effect on the impact strength, tensile properties, and internal morphology of the ternary blend. The impact strength, tensile strength, and elongation at break increased with ECH content; thereafter, they decreased on further increasing the ECH content. At 0.5 wt % ECH content, impact strength, tensile strength, and elongation at break reached the maximum values and smaller salami structure particles were observed accordingly. These results were attributed to the competition of shear resistance of TPCLS and the chemical linkage between the crosslinked starch and PLA-g-MA. (C) 2015 Wiley Periodicals, Inc.