Four dry corn starches with different amylose content were blended at 185degreesC with poly(lactic acid) (PLA) at various starch:PLA ratios using a lab-scale twinscrew extruder. Starch with 30% moisture content also was blended with PLA at a 1:1 ratio. Each extrudate was ground and dried. The powder was mixed with about 7.5% plasticizer, and injection molded (175degreesC) into test tensile bars. These were characterized for morphology, mechanical properties, and water absorption. Starch performed as a filler in the PLA continuous matrix phase, but the PLA phase became discontinuous as starch content increased beyond 60%. Tensile strength and elongation of the blends decreased as starch content increased, but no significant difference was observed among the four starches at the same ratio of starch: PLA. The rate and extent of water absorption of starch/PLA blends increased with increasing starch. Blends made with high-amylose starches had lower water absorption than the blends with normal and waxy corn starches. (C) 2003 Wiley Periodicals, Inc.