Grafting vinyl monomers onto wool fibers. I. Graft copolymerization of methyl methacrylate onto wool using V⁵⁺–thiourea redox system

Abstract

SynopsisThe graft copolymerization of methyl methacrylate in wool fibers was investigated in aqueous solution using Vs+-thiourea redox system. The rate of grafting was determined by varying monomer, thiourea, acidity of the medium, temperature, nature of wool, different acrylic monomers, and reaction medium. The graft yield increases significantly by increasing reaction time in the initial stages of the reaction but it does slow down on prolonging the duration of grafting. The effect of increasing monomer concentration brings about a significant enhancement in the graft yield. The graft yield increases with increasing thiourea concentration, but beyond 0.0075M, the percentage graft yield decreases. The graft yields are considerably influenced by chemical modification prior to grafting. Wool reduced with thioglycolic acid is more susceptible to grafting than untreated wool; the opposite effect is noted in the case of trinitrophenylated and esterified wools. A suitable kinetic scheme has been proposed and the rate equation has been evaluated.

Kinetic modeling of free‐radical graft polymerization

“…ample, monomer concentration and reaction temperature). Kinetic models which have been proposed to describe the mechanism of graft polymerization are restricted to special cases (Fox et al, 1959;Nayak et al, 1978;Sahoo et al, 1986; S. R. Samal et al, 1984;Sundardi, 1978;Tripathy et al, 1985; Hernandez, 1990).…”

“…Samal et al, 1984;Sundardi, 1978;Tripathy et al, 1985; Hernandez, 1990). Qualitative analytical solutions yielding the order of the grafting reaction (Fox et al, 1959;Nayak et al, 1978;Sundardi, 1978;Tripathy et al, 1985) and the number-average molecular weight of the grafted polymer (Fox et al, 1959) were obtained by employing a variety of assumptions, including the quasisteady-state assumption (QSSA) and the long-chain hypothesis (LCH). The use of the QSSA and LCH in numerical algorithms, however, is limited.…”

Grafting Vinyl Monomers onto Chitosan:IV:Graft Copolymerized of Acrylicacid onto Chitosan Using Ceric Ammonium Nitrate as the Initiator— Characterization and Antimicrobial Activities

“…Grafting vinyl monomers onto natural and synthetic polymers is a challenging field of research with unlimited future prospects. During the last four decades Nayak and co-workers have studies the graft copolymerization of several monomers onto a multitude of natural and synthetic polymers like wool, silk, cellulose, nylon and PET, rubber to enhance their properties using various initiators like hexavalent chromium, quinquevalent vanadium, tetravalent cerium, trivalent manganese, peroxydisulphate and peroxydiphophate ions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”