Granular starch is added to a polymer in order to decrease the cost of the polymer derivative. Use of granular starch also makes the derivative more biodegradable. The polymer blend has very similar mechanical properties to pure polymer. Furthermore, unlike other starch/polyethylene mixtures, glycerol is not added to the mixture. This reduces the water absorbency of the final product. The polymer and starch are blended together in the presence of an interfacial compatibilizer that binds the two components together.
(Board of Trustees of the University of Arkansas, USA)
Sun, Z., Liu, W., & Wang, Y. (2009). Biodegradable materials from starch-polymer blends. Patents Granted. Retrieved from https://scholarworks.uark.edu/pat/86