The Influence of Biobased Olegomeric Diisocyanate on Thermal and Mechanical Properties of Poly (3-hydroxybutyrate)

In the present work, poly (3-hydroxybutyrate) (PHB) blends were prepared by melt blending with biobased oligomeric diisocyanate synthesised from hexamethelene diisocyanate (Tolonate XFLO100 (TXF100)). PHBTXF100 blends with four different weight fraction (10, 15, 20 and 25 phr) of TXF100 were prepared and characterized for mechanical, thermal and thermomechanical properties. Strain at break and tensile toughness of PHBTXF10025 blend were improved by 200% and 193%, respectively. PHBTXF100 blends showed a broad glass transition temperature with a decreased onset temperature compared to PHB. PHBTXF100 blends exhibited low crystallinity than PHB, and was further decreased with an increased weight fraction of TXF100. Elastic and storage moduli PHBTXF100 blends were decreased compared to PHB, and correlated to their low degree of crystallinity. The changes in mechanical properties of PHBTXF100 blends were mainly due to efficient weakening of intermolecular interactions in the amorphous regions of PHB, and also a slight decrease in crystalline order of PHB.