Impact of ZnO Nanoparticles on Thermal Properties of Poly(3-hydroxybutyrate-co-10 mol % 3-hydroxyhexanoate) Copolymer

Abstract

Biopolymer composites using poly(3-hydroxybutyrate-co-10 mol % 3-hydroxyhexanoate) (P(3HB-co-10 mol % 3HHx)) and ZnO nanoparticles (NPs) were prepared by solution casting method and the effect of ZnO NPs on thermal properties of the prepared biopolymer composites (P(3HB-co-10 mol % 3HHx)/ZnO NPs) were studied using DSC, TGA, GPC, and thermal conductivity analyzer. DSC analysis revealed the dual melting behavior of both neat P(3HB-co-10 mol % 3HHx) and its composites. It also showed that the incorporation of ZnO NPs into P(3HB-co-10 mol % 3HHx) decreased the melting temperature Tm, but increased the melting enthalpy ΔHm and degree of crystallinity Xc of the composites. Compared to neat P(3HB-co-10 mol % 3HHx), the initial degradation temperature T99 of the prepared composites was decreased and vice versa for final degradation temperature due to the addition of ZnO NPs which was revealed from TGA results. The observed thermal conductivity value of neat P(3HB-co-10 mol % 3HHx) and its composites were in between ~5.6 × 10–2 and ~7.9 × 10–2 W m/K with the very high value noticed for 30% ZnO NPs reinforced P(3HB-co-10 mol % 3HHx) composites. Overall P(3HB-co-10 mol % 3HHx)/ZnO NPs composites exhibited high thermal diffusivity and thermal effusivity compared to neat P(3HB-co-10 mol % 3HHx) with very high value noted for 30% ZnO NPs and 5% ZnO NPs reinforced P(3HB-co-10 mol % 3HHx) composites respectively which is essential for thermal related applications.