Uncatalyzed photografting of polyacrylamide from functionalized cellulosicand lignocellulosic materials

Photoinitiated graft copolymerization of polyacrylamide (PAAm) occurred on one cellulosic (cotton fabric) and one lignocellulosic (sisal fiber) substr ate using a novel photocatalytic system. The samples were photoexposed with oxalic acid solutions, differing in acid concentrations, which functionali zed the backbone materials to different extents with carboxyl groups, and a t the same time rendered them photoactive. Afterwards, the functionalized s amples were again photoexposed with monomer (AAm) solution and photograftin g was found to take place without any initiator from outside. The effects o f increased acid dose level and increased monomer concentration on differen t grafting parameters were measured. The graft copolymer formation was conf irmed by FTIR and DSC studies; XRD and SEM techniques were applied for morp hological studies. Textile-related properties, namely tensile properties, m oisture regain, and dye uptake properties of both the ungrafted and grafted materials were also measured using proper instruments and techniques. (C) 1999 John Wiley & Sons, Inc.