Uncatalyzed photografting of polyacrylamide from functionalized cellulosic and lignocellulosic materials

Abstract

Photoinitiated graft copolymerization of polyacrylamide (PAAm) occurred on one cellulosic (cotton fabric) and one lignocellulosic (sisal fiber) substrate using a novel photocatalytic system. The samples were photoexposed with oxalic acid solutions, differing in acid concentrations, which functionalized the backbone materials to different extents with carboxyl groups, and at the same time rendered them photoactive. Afterwards, the functionalized samples were again photoexposed with monomer (AAm) solution and photografting was found to take place without any initiator from outside. The effects of increased acid dose level and increased monomer concentration on different grafting parameters were measured. The graft copolymer formation was confirmed by FTIR and DSC studies; XRD and SEM techniques were applied for morphological studies. Textile-related properties, namely tensile properties, moisture regain, and dye uptake properties of both the ungrafted and grafted materials were also measured using proper instruments and techniques.

Optimized conditions for the grafting reaction of poly(methyl methacrylate) onto oil‐palm empty fruit bunch fibers

“…Recently, the grafting copolymerization of various vinyl monomers onto natural cellulosic or lignocellulosic fibers has attracted many researchers interested in enhancing the fiber properties 7–9. The grafting of acrylonitrile onto pineapple leaf fiber improved the thermal properties of pineapple leaf fiber,7 whereas the grafting of acrylamide onto sisal fiber improved the water resistance of sisal fiber 8. The grafting of MMA onto jute fiber enhanced the mechanical properties of jute fiber 9.…”

Characterization of Methyl Methacrylate Grafting onto Preirradiated Biodegradable Lignocellulose Fiber by γ‐Radiation

“…It has been reported [7] that the preirradiation grafting method showed higher elongation than a ceric-ion initiation method. Several authors have suggested that the radiation-induced graft copolymer synthesis is the preferred technique to improve the properties of natural cellulose [7,8] and synthetic polymers, [9,10] as it allows a considerable degree of control over the graft copolymer chain. The graft copolymer reaction initiated by g-radiation is normally carried out by one of the following methods: direct irradiation of the polymer immersed in a solution of monomer and other additives, or preirradiation of the polymer followed by reaction with the monomer.…”