PHYSICAL-MECHANICAL AND DEGRADATION PROPERTIES OF THERMOPLASTIC STARCH DEPENDING ON THE COMPOSITION OF THE STRUCTURE-FORMING MODIFYING ADDITIVE

The composition of thermoplastic starch (TPS) was prepared using glycerol as a plasticizer, lactic acid and its binary mixture with stearic acid. A number of component concentrations and thermo-mechanical technological parameters were varied during starch processing and formation of film-forming compositions. Physical-mechanical tests of TPS film samples were carried out, and the strength and elasticity properties were determined depending on the concentration of plasticizer and structure-forming additives. The effect of UV irradiation on the degradability of TPS compositions and TPS film samples with synthetic polymer - polyethylene was studied. The optimal composition, loss of strength and elasticity in the range of 80–100% after 90 days of aging in a climate chamber were determined. Mass spectrometric study of TPS films before and after UV irradiation confirmed the influence of structure-forming additives of stearic and lactic acids on the degradability of TPS compositions. The obtained results indicate the possibility of forming plastic materials with the ability of rapid degradation under environmental conditions.