Effect of grafting acrylic acid, N-vinyl pyrrolidone and their mixture on the properties of polyester fabric

Abstract

The effect of grafting acrylic acid, N-vinyl pyrrolidone and their mixture on the hydrophilic, electrical, dyeing, thermal and mechanical properties of poly(ethylene terephthalate) fabric has been studied. Grafting improves significantly the water content, the water sorbency and the electrical conductivity of the fabric. Salt treatment of poly(ethylene terephthalate)-graft-poly(acrylic acid) and poly(ethylene terephthalate)-graft-poly(acrylic acid-co-N-vinyl pyrrolidone) causes further increase in the electrical conductivity. The dyeability of the fabric towards basic, direct and disperse dyes is also improved by grafting. The thermal gravimetric analysis, differential scanning calorimetry and X-ray diffraction analysis show the deteriorating effect of grafting. The activation energy for the thermal decomposition of the second stage and the fabric relative crystallinity are found to decrease linearly with the increase in graft yield. The rate of decrease in the activation energy with the increase in graft yield depends on the type of grafted monomer. The tensile strength and Young’s modulus decrease with the increase in degree of grafting while the elongation-at-break shows different dependence.