Methods of grafting

The double irradiation method involving the mutual method of grafting of vinyl monomers onto preirradiated polymer recently used by Kaur et al. [85]. 

In addition, there is the difficulty of controlling the grafted side chains in molecular weight distribution. In the context of this chapter, the authors hope to give a systematic, comprehensive, up-to-date review on the various methods of grafting, the methods used for characterization of grafted substrates, and their possible end use applications. 

If polyvinyl alcohol is used as the reducing agent and the oxidation is conducted in the presence of vinyl monomer, grafting occurs. This method of grafting yields substantially pure graft copolymers since the free radicals are formed exclusively on the polymer backbone. 

The xanthate method [62] is considered as one of the most promising methods for industrial chemical modification. The principal involved in the xanthate method of grafting is that cellulosic xanthate either ferrated or in acidic conditions reacts with hydrogen peroxide to produce macroradicals. The following reaction mechanism has been proposed ... 

A method of grafting vinyl monomers to substrates of cellulose xanthate was invented by Faessinger and Conte-. The initiation is a reaction of ferrated (12) or acidic (13) cellulose xanthate with hydrogen peroxide according to the following scheme (HO-OH and Fe + give HO- radicals) ... 

Kokta, B.V., Lo, R.C. and Daneault, C. (1982). The xanthate method of grafting IX. Grafting of acrylonitrile onto high yield hardwood pulp. In Graft Copolymerization of Lignocellulosic Fibers, Hon, D.N.S. (Ed.). ACS Symposium Series, 187, pp. 269-283. 

Various methods of graft and block copolymerization have been described in the literature (radical, irradiation, condensation, etc.). The reader is referred to the specialized books (1-3) in regard to synthesis, characterization and properties. 

Homopolymer was formed by both methods of grafting however, the amount was considerably greater with the immersion method. When the time of grafting in solution was increased beyond 30 minutes, the extent of grafting continued to increase, but there was a tendency for the homopolymer to crosslink and become embedded in the foam. When this occurred, beads of crosslinked homopolymer were trapped in the cells of the foam, and they could not be removed by subsequent washing. 

Characterization of the structure of grafted surface is crucial, because abetter understanding of the grafted surface will be a key factor for further developing this new technology. In this article, various methods of grafting and surface characterizations, and applications associated with grafting from recent literature publications will be reviewed. 

Recorded efforts to deal with damage to skin tissue date to the second century b.c.e., when an Indian surgeon hy the name of Sushruta (fl. sixth century b.c.e.) developed a method of grafting skin taken from one part of a patient s body to replace a lost nose. Amputation of noses was a common procedure at the time, partly because of... 

The Ceric Ion Method of Grafting Acrylic Acid to Cellulose... 

Bhattacharya M., Jacob J., Vaidya U. Method of grafting functional groups to synthetic polymers for making biodegradable plastics. World patent (US) WO9747670 (1997). 

Different methods for the immobilisation of ionic liquids have been tested. These can be divided into two different categories a) via the inorganic anion (method of incipient wetness and b) via the organic cation, here a methyl-alkyl-imidazolium cation. The method of incipient wetness was presented by Hoelderich [5], we concentrate on the immobilisation of ionic liquids by the methods of grafting or by synthesising organically modified MCM 41 materials (Sol gel method) (seeFigure 1). 

Many different methods of grafting have been developed. By far the greatest effort has been via free-radical vinyl-polymerization routes. The general reaction scheme is shown below ... 

Enzymatic assay of lipid hydroperoxides A selective assay has been described for lipid hydroperoxides, based on the cyclooxygenase reaction with a sensitivity in the range of 20-200 pmol (Marshall et al., 1985 Pendleton and Lands, 1987 Lands, 1988). The substrate (15-HPETE) is not, however, commercially available and must therefore be synthesized from purified arachidonic acid by the method of Graft (1982) in which soya bean lipoxygenase is used to catalyse the stereospecific oxygenation of arachidonic acid. 

Hu L, Hach D, Chaumont D, Brachais C-H, Couvercelle J-P, Percheron A (2009) Comparison of various methods of grafting of modified-PEG onto maghemite nanoparticles in aqueous medium including synthesis by microwave refluxing. J Sol-Gel Sci Technol 49 277-284... 

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