Obtention and characterization of poly(3-hydroxybutyricacid-co-hydroxyvaleric acid)/mcl-PHA based blends

The aim of this work was to evaluate the physical-chemical properties of blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and a medium-chain-length polyhydroxyalkanoate (LA). Blends were obtained by casting film-solution on leveled trays. Morphological analysis showed compatibility between the two polymers up to 5 g/100 g of LA polymer was added and phase separation in the polymeric system for compositions containing more than 5 g/100 g of LA polymer. TGA data and glass transition temperatures revealed some compatibility of the polymers. Moreover, there is a significant decrease of melting temperature and elasticity modulus for PHBV-LA blends with composition. Films containing 5 g/100 g of LA polymer showed an improvement of 50% in elongation to break (SB) when compared with pure PHBV. For other samples the SB decreased most likely due to the lack of adhesion between the two polymeric phases.

► In this study new mcl-polyhydroxyalkanoates (mcl-PHAs) were produced in our laboratory. ► This mcl-PHAs presented elastomeric properties and were blended with PHBV for improve PHBV mechanical properties. ► Blends were miscible in some extend and PHBV mechanical properties were improved.