Chemical Modification of Starch Nanoparticles

Starch is an abundant, inexpensive, naturally renewable, and biodegradable polysaccharide found in the roots, stalks, and seeds of staple crops such as rice, corn, wheat, tapioca, and potato. Chemical modification of nanosized starch particles expands the types of polymers that can possibly be used as matrices. This chapter discusses the general methods for chemical modification of starch nanoparticles (StNP) in detail. Starch nanocrystals obtained by hydrolysis and regeneration-co-crystallization have surface hydroxyl groups that give them a polar surface. Chemical modification of starch nanocrystals alters the surface characteristics of the starch nanocrystals. Chemical modifications can change filler-filler and filler-matrix interactions and hence affect the compatibility of the StNP and polymer matrices, and even form new microstructures in nanocomposites. Meanwhile, chemically modified StNP still contribute to unique functions.