Esterified and polyester-grafted starch and alloy thereof

摘要

A starch which has been esterified and grafted with a polyester. The esterifying acid is at least one member selected from among saturated and unsaturated C2-18 fatty acids and aromatic carboxylic acids. The polyester is a polymer prepared by the ring opening of at least one member selected from among lactones with 4- to 12-membered rings, and the terminal hydroxyl group thereof is substantially blocked with an ester group. A molded article obtained from the starch can easily achieve the desired flexibility and a toughness on a practical level and has moisture-related characteristics on a practical level, even when it contains no or little plasticizer.