Polyester fiber was grafted with polyvinylacetate (PVAc) using gamma radiation to different PVAc contents. Moisture regain decreased slightly from 0.38% to 0.34%; crystallinity index did not show any appreciable change due to grafting. These grafted polyester fibers were dyed with disperse dyes at 100°C and 130°C. It was observed that saturation dye uptake as well as rate of dyeing increased with PVAc content. The above phenomenon could be attributed to the increased affinity of the grafted fiber to the dyes investigated and the increase in diffusion coefficient due to the plasticization action of PVAc.

Polyester fiber was modified by grafting with polyvinyl alcohol (PVA) by the irradiation process. Initially, polyester fiber was grafted with polyvinyl acetate and then hydrolyzed under suitable conditions to get polyester-graft-polyvinyl-alcohol. Crystallinity of the grafted fibers was determined by infrared, DSC, and x-ray analysis and was found to be identical for all the grafted fibers. Moisture regain increased with increase in PVA and had a value of 1.6% at 13% PVA content. The grafted fibers were dyed with disperse dyes: Dispersol Fast Yellow G and Duranol Red 2B at 100° and 130°C. Saturation dye uptake showed an initial increase with PVA, attained a maximum at about the 8% graft level, and then decreased at higher PVA contents. Half dyeing time decreased with PVA content, attained a minimum, and then showed an increase. Except for the numerical values, both dyes followed identical patterns at different temperatures.