Mechanical performance of wool fabrics grafted with methacrylamide and 2-hydroxyethyl methacrylate by the Kawabata Evaluation System for Fabric method

Wool fabrics were graft copolymerized with methacrylamide (MAAm) and 2-hydroxyethyl methacrylate (HEMA) in aqueous media, using a chemical redox system as an initiator. After grafting, the mechanical properties related to the hand evaluation, such as tensile, shearing, bending, compression and surface properties of wool fabrics, were evaluated by means of the Kawabata Evaluation System for Fabric. The surface morphology was examined by scanning electron microscopy. The results revealed that the surface morphology and low-stress mechanical properties of wool fabrics were remarkably changed after grafting with HEMA. The weight gain of the wool fabrics grafted with HEMA increased rapidly in the initial grafting stage and reached saturation level at 17 wt% after 20 minutes. Small deposits of oligomers were visible on wool surfaces and typical scale patterns were changed after grafting wool fabric with HEMA. The slope of the shearing hysteresis curves in the weft and warp directions for wool fabrics grafted with HEMA was increased compared with the control and wool fabrics grafted with MAAm. These results imply that the changes in tensile, shearing, bending and compression behavior of grafted wool fabrics are due to the reduction of the free internal volumes of the fabrics, leading to a tightening of its texture.