The Biodegradation of Polyhydroxybutyrate-co-valerate/Amphiprotic Starch in the Presence of Microorganisms

The increasing comsumption of plastics has generated environmental problems because it takes more than a hundred years for a discarded polymer to degrade. The ideal plastic should present desirable industrial properties and be degradable within a satisfactory time period. Researches is conducted to plastics with good properties for packaging but that are biodeoradable when discarded to the environment. In this work we evaluated the biodegradation of the blend of the copolymer poly(hydrozybutyrate-hydrozyvalerate, PHB-HV, which is a natural, biodegradable and biocompatible thermoplastic, and of the starch amphiprotic, in the proportion of 75 and 25% m/m, respectively. The results were obtained through the Sturm test. it methodology for the evaluation of biodegradation in the presence of a mixed culture of Phanerochaete chrysosporium and Talaromyces wortmannii fungi. The results pointed to biodegradation of the blend as it function of the time. with the appearance of terminal carboxylic groups. Ill addition. a new crystalline symmetry was observed ill the polymeric structure.