RECENT PROGRESS IN STARCH-BASED POLYMERIC MATERIALS

Starch, as a natural polymer, has the advantages of renewability, biodegradability, abundance and low cost, and has received great attention in non-food applications for a long time. However, starch cannot be used alone as a polymeric material due to its insolubility in cold water, poor shearing stability and water resistance, and absence of melting flow. Therefore, it should be chemically/physically modified in order to strengthen some functions or form some new properties. This review provides an insight into some developments in the chemical and physical modification of starch for its applications in biodegradable plastics, absorption materials, tissue engineering scaffold and drug carriers primarily based on the publications that appeared during the last five years. The chemical modification of starch included esterification, etherification, oxidation, crosslinking and graft polymerization. The physical modification of starch focused on the blending of starch with other biodegradable polymers such as aliphatic polyesters, poly( vinyl alcohol) and other natural macromolecules. Starch nanocrystals obtained by acid hydrolysis were also reviewed, and they can be functionalized or used to enhance the mechanical properties of starch or other polymer materials. As a kind of renewable material, starch, especially the non-food starch should receive more and more attentions in the preparation of practical polymeric materials in the future.