Correlation between mechanical adhesion and interfacial properties of starch/biodegradable polyester blends

Biopolymers are preferred ingredients for the manufacture of materials beca use they are based on abundantly available and renewable raw materials that have benign environmental problems associated with their production, fabri cation, use, and disposal; however, the wide use of biopolymers in engineer ing applications has not been achieved, mainly because of the inferior qual ity of many biopolymer-based products. To overcome this limitation, studies have been initiated on blends of biopolymers and biodegradable synthetic p olymers. We used the contact angle of probe liquids to measure the surface energy of polystyrene, the biodegradable polyesters polycaprolactone, poly( hydroxybutyrate-co-hydroxyvalerate) polylactic acid, polybutylene adipate t erephthalate, and adipic poly(hydroxy ester ether), and normal starch. The surface energies were used to estimate the starch/polymer interfacial energ y and work of adhesion. The calculated starch/polyester work of adhesion sh owed mixed correlation with published starch/polyester mechanical propertie s, indicating that factors other than interfacial properties might be domin ant in determining the mechanical properties of some starch/polyester blend s. (C) 2001 John Wiley & Sons, Inc.