Polymer Blends made of Poly(3-hydroxybutyrate-co-3hydroxyhexanoate) and Epoxidized Natural Rubber: Thermal and Mechanical Response

摘要

The ever-increasing demand of biodegradable over conventional polymers places microbial polyhydroxyalkanoates (PHA) as an ideal choice of research material for specific applications. In this study, polymer blends made of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx) and epoxidized natural rubber (ENR) were prepared using solution casting technique. The influence of ENR on thermal, morphological and mechanical properties of P(3HB-co-3HHx) was investigated. There are two glass transition (T_g) temperatures observed using differential scanning calorimeter. This indicates that P(3HB-co-3TIHx) and ENR are immiscible at macroscopic level. Although the T_g of P(3HB-co-3HHx) is seen to shift toward ENR in the least maimer, infrared analysis suggests that the crystal structure of P(3HB-co-3HHx) retains its conformational structure. Li terms of morphology, ENR exists as droplets in P(3HB-co-3HHx)-rich phase, e.g. at ENR weight fraction (w_(ENR)) of 0.3. In dynamic mechanical analysis, all blend compositions exhibit sobd-lilce behavior, with storage moduli larger than loss moduli, across the frequency sweep at room temperature.