Tailoring surface properties of cellulosic fibers through chemically initiated graft copolymerization of butyl acrylate.

In the present communication, surface modification of Hibiscus esculentus (HE) fiber has been reported through graft copolymerization with butyl acrylate (BA) monomer using ascorbic acid and hydrogen peroxide as redox initiator. Different reaction parameters such as time, temperature, initiator concentration and monomer concentration were optimized to get maximum graft yield. The grafting percentage showed dependency on concentration of ascorbic acid, hydrogen peroxide and monomer as well as on reaction time and temperature. Maximum percentage of grafting was achieved when concentration of ascorbic acid, hydrogen- peroxide and monomer was 2.55×10^-2 mol/L, 1.61×10^-1 mol/L and 1.41×10^-1 mol/L respectively at a temperature of 45 °C for reaction time of 90 minutes. Various grafting parameters such as graft yield, grafting efficiency and kinetic parameters such as rate of graft copolymerization, rate of polymerization and rate of homopolymerization have also been calculated. From kinetic study of graft copolymerization it has been found that rate expression for graft copolymerization was R_g= k [Asc]^0.94 [H₂O₂]^0.40 [BA]^0.77. The activation energy for graft copolymerization of BA has been found to be 21.837 KJ/mol. The graft copolymers thus formed were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and thermo-gravimetric analysis. Thermo-gravimetric analysis showed enhanced thermal stability of grafted fibers as compared to raw fibers. Further swelling behavior of raw and grafted fibers in different solvents, moisture absorption behavior and resistance to chemicals were investigated in order to use them in different environments. [ABSTRACT FROM AUTHOR]