Grafting of Methacrylic Acid onto Poly(Ethylene Terephthalate) Fibers Using Azobisisobutyronitrile

Poly(ethylene terephthalate) fibers were grafted with methacrylic acid using azobisisobutyronitrile. The graft yield was observed to increase between 60 and 90°C and reached 32% at 90°C. An increase in monomer concentration increased the graft yield. The optimum concentration for initiator was found to be 3.0 × 10−3 mol/L. Grafting decreased the density and increased the diameter of the fiber. Moisture regain and dyeabilities of the fibers with basic dyes increased due to —COOH groups introduced into the fiber structure through grafting. However, grafting resulted in a decrease in the decomposition temperatures of fibers. Micrographs revealed that the homogeneous appearance of the fiber surface changed with an increasing degree of grafting, and the surface took on a shell-like appearance at high graft yields.