Optimization and synthesis of cellulose acetate based grafted gel and study of swelling characteristics

Abstract

Modification by chemical grafting is one of the techniques to enhance functional moieties of biopolymers. Which enhances the properties of biopolymer and makes it capable to be used in various fields such as waste water treatment, food industry and pharma industry etc. In this investigation cellulose acetate based grafted gel was synthesized and its swelling characterization was examined in terms of swelling percentage to explore its hydrophilic character. Microwave radiation technique was used for the synthesis of cellulose acetate gel using acrylic acid monomer on to viscid cellulose acetate solution with potassium persulphate as an initiator. Reaction parameters (amount of solvent, initiator concentration, reaction duration and monomer concentration) impacting the product yield of grafted gel, were optimised as a function of percentage grafting (Pg.). Characterization of grafted gel was done by physico-chemical techniques viz FTIR (Fourier transform infrared spectra analysis), XRD (X-ray diffraction), (TGA) Thermal gravimetric analysis. For investigating the water uptake potential of grafted gel, the swelling studies were carried out. The effect of pH on the swelling behaviour of cellulose acetate synthesised gel was examined by taking three pH buffer solutions 4, 7, 9. The maximum swelling percentage was obtained with 9 pH buffer solution. Fickian and nonfickian swelling models were applied, the ‘n’ (diffusion exponential) value less than 0.5 indicated fickian model i.e. swelling occurred through controlled diffusion.