Biodegradable Composites Based on Poly(3-hydroxybutyrate) and Polylactide Polyesters Produced from Vegetable Raw Materials

Composites of various composition are obtained by the solid-phase mixing of thermoplastic polyesters poly(3-hydroxybutyrate) and polylactide under conditions of shear deformation in the presence of poly(ethylene glycol) as a plasticizer. The thermophysical parameters in primary and secondary heating scans are measured. It is shown that the original polyesters are immiscible polymers. The degree of crystallinity and the enthalpy of melting of the polymers in the individual state and in blends are calculated. It is found that upon secondary heating the temperature transitions and the degree of crystallinity of these polymers change. The mechanical and rheological properties of the composites are investigated. A study of mold fungi resistance demonstrates that, unlike polylactide, poly(3-hydroxybutyrate) is a completely biodegradable polymer, while the biodegradability of the composites is determined by their composition.