Synthesis, characterization and material properties of novel poly vinyl acetate grafted pectin

Abstract

Graft copolymerization of vinyl acetate (VAc) on pectin was performed using a redox initiator ceric ammonium nitrate (CAN). The grafting conditions were optimized by studying the effect of monomer, vinyl acetate (VAc) and initiator (CAN) concentrations as well as temperature and time. These variables appreciably affected the percentage of grafting and grafting efficiency of the grafted pectin (GP). GP was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Thermal properties of GP were evaluated by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). DSC result showed a slight elevation in glass transition temperature (Tg) of the GP in comparison to pectin. XRD study revealed an increase in crystallinity of the pectin after grafting with VAc. This indicates that the chemical structure and morphology of pectin changes after modification. TGA exhibits an increase in thermal stability of the grafted copolymer as compared to the reference pectin.