Two-hydroxyethyl methacrylate was grafted onto cotton cellulose using photoinitiation technique in the presence of the photoinitiator benzoin ethyl ether. Various parameters of the graft-copolymerization reaction, namely time, temperature, initiator, and monomer concentrations, were optimized using the grafting bath containing 10% methanol/acetone to dissolve the photoinitiator. The cotton sample, preswollen in sodium hydroxide, was subjected to grafting under optimized conditions. The preswollen samples showed higher graft add-on values at the equivalent monomer concentration. The moisture regain initially decreased at lower graft add-on levels and increased marginally with higher graft add-on. This behavior of the grafted substrate with respect to moisture regain has been explained.
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Cotton is a versatile, natural fiber possessing a number of useful textile properties. It is highly prone to various kinds of chemical modifications and, hence, has been subjected to a variety of reactions in the past. The graft-copolymerization, using vinyl monomers, is a reaction that modifies the fiber properties in accordance with the nature of the monomer used for grafting. Photo-induced grafting, using UV radiation, is among the most promising and practical methods of graft-copolymerization because of its simplicity.
Photoinduced graft-copolymerization of cellulose with the use of photoinitiators such as dyes, metal ions, hydrogen peroxide, 374 etc., has been reported. Ceric ion was found to accelerate UV-radiation induced photografting of methyl methacrylate onto c e l l ~l o s e . ~~~ Davis et al.7 have reported photoinduced graft-copolymerization of styrene and methyl methacrylate onto cellulose by using alcohols as solvents in the presence of various photoinitiators. The effect of organic solvents on the swelling of cotton fiber for improved graft-copolymerization was studied by * To whom correspondence should be addressed.