Abstract
Environmentally friendly polymeric biocomposites based on whey powder, a waste material of the dairy industry, and fully or partially hydrolyzed poly (vinyl alcohol) were prepared and characterized with optical microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and stress–strain analysis, and their biodegradation was evaluated with the modified Zahn–Wellens method and the spectrophotometric determination of poly(vinyl alcohol). In addition, the ability of the biocomposites to absorb moisture and its consequent influence on the mechanical properties were investigated under different storage conditions. The structural differences of the two types of poly(vinyl alcohol) matrices had a significant effect on all the mentioned characteristics. Possible molecular interactions between the polymer matrix and modifier, due to hydrogen bonding, were also examined. First‐order kinetics were applied for the biodegradation data. The two‐phase character of the biodegradation was shown. The results indicated that whey powder is suitable for the modification of polymers, and this is important for the production of biodegradable polymer materials and the consequent reduction of the environmental load. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007