Synergistic effect between different clays and plasticizer on the properties of PHBV nanocomposites

The aim of this study was to evaluate the effect of the plasticizer triethyl citrate (TEC) combined with two different clays [unmodified bentonite (Bent) and halloysite (Hal)] on the morphology, crystallization behavior, and mechanical properties of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV). The compositions were prepared with 3 wt% clay and 10 wt% TEC by melt processing. The addition of TEC resulted in a plasticized effect with 15 degrees C lower glass transition temperature compared with the neat PHBV. An increase in the mechanical performance was achieved when clay and plasticizer were combined, and this improvement was dependent on the degree of dispersion of the nanoparticles in the polymer matrix. For the combination of Hal and TEC, which most affected the crystallization process of PHBV, the impact strength was improved by 135% without a significant loss in the elastic modulus of the material. The synergistic effect between the plasticizer and clay was responsible for these improvements, making this a viable alternative for extending the use of this polymer in various industrial applications. POLYM. COMPOS., 40:3835-3843, 2019. (c) 2019 Society of Plastics Engineers