Chitin nanocrystals grafted with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and their effects on thermal behavior of PHBV

► Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was successfully grafted onto the surface of chitin nanocrystals via chloridization reaction. ► The hydrophobic of chitin was improved by this way. ► Both original and modified chitin nanocrystals suppressed crystallization of PHBV. ► The melt point of PHBV was increased after being mixed with nanofillers. Chemically modified chitin nanocrystals were synthesized by grafting poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) onto chitin backbone via chlorination. Acetyl amino group was maintained in the reaction. The chemical structure and morphology of PHBV grafted chitin nanocrystals were characterized by Fourier transform infrared, Transmission electron microscopy and X-ray photoelectron spectroscopy. Contact angle measurement showed that the lipophilicity of chitin was improved by the surface modification. The effects of original chitin and PHBV-graft-chitin nanocrystals on the crystallizing and melting behavior of PHBV were studied by differential scanning calorimeter (DSC). The results indicated that both unmodified and modified chitin nanocrystals suppressed crystallization of PHBV. The melt point of PHBV was increased after being mixed with nanofillers.