Mechanical spectroscopy study on biodegradable synthetic and biosynthetic aliphatic polyesters

Miscibility behavior and rheological properties with mechanical spectroscopy study of both poly(3-hydroxybutyrate) (PHB)/poly(ethylene oxide) (PEG) and biodegradable synthetic aliphatic polyester (BDP)/linear low density polyethylene (LLDPE) were investigated. Blends of BDP with LLDPE were immiscible, showing two separate Tg values in all compositions; whereas blends of PHB with PEO were miscible, showing a single Tg in the whole range of compositions. However, the shear viscosities of both synthetic and biosynthetic blend systems decrease with increasing shear rate, When a modified Cole-Cole plot of the blend system is further considered, the logG'-logG'' plot shows little sensitivity to a variation in both LLDPE composition for synthetic BDP and PEO composition for biosynthetic PHB. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate (P(3HB-co-3HV)) random copolymers were also investigated.