analyzing the swelling behavior of persian gum-g-polyvinyl acetate film using ternary interaction parameter

Low water resistance of sustainable biopolymers such as persian gum (pg) has limited their use in various applications. to overcome this problem, in this study, vinyl acetate (vac) was grafted onto the pg chains at various amounts using a redox system. the results of ftir spectroscopy on pg and pg-g-pvac after removing pvac homopolymers using soxhlet extraction method confirmed the successful grafting of monomers onto pg. the swelling behavior of the samples in water followed a pseudo-fickian diffusion mechanism. although pg easily dissolved in water, copolymerizing pg with vac reduced its water solubility. furthermore, increase in the vac content from 20 to 80 wt. % in the formulation reduced the diffusion exponent of m from 0.359 to 0.215. thus, the equilibrium swelling ratio of the copolymers decreased from about 4.7 to 2. this result was in accordance with increase in the ternary flory-huggins interaction parameter.