Proof of grafting

Proof of Grafting. The presence of the lignin-PS graft copolymer in the extract was shown by absorbance spectroscopy, as shown in Figure 4. In Figure 4(a) a dilute solution of the extract in toluene shows an absorbance... 

Proof of grafting was presented through comparison of the solubilities of their saponified vinyl acetate and cellulose grafts and of the physical mixtures of the corresponding homopolymers. While from a cupriethyl-enediamin solution of the physical mixture pure cellulose is precipitated on acidification, the precipitate from the graft solution always contains constant amounts of polyvinyl alcohol, as proven by infrared spectroscopy. 

Table I presents the results of irradiation of mixtures of wheat starch and vinyl acetate. In this series, as in the previous one, a dose of 8 Mrep was used and the grafted products were hydrolyzed in order to obtain proof of grafting. It was...

If the grafted chain is polyacrylic acid or polymethyl methacrylate, then we look for an increase in the percentage of oxygen as proof of grafting. 

The usual proof of graft copolymerization is based upon changes in solubility between the starting polymer and the graft copolymer. Some workers have measured some physical property, such as contact angle or wetability, and used a change in that parameter as an indication of the formation of a graft copolymer. in previous work from this laboratory... 

One may perform radical graft copolymerizations onto the butadiene region of copolymers of styrene and butadiene without any reaction occurring at the styrene portions of the copolymer. If the monomer is reactive, reaction of the monomer at an allylic site occurs while for less reactive monomers, the polymeric radical is formed and this adds to the double bond of the polymer. Proof of the site of grafting comes from information about the relative efficiency of different initiators but the most important information is obtained from infrared spectroscopy. One can observe differences in the spectra which can be related to the mode of addition. 

Table VII. Water retention of grafted HEC, dissolving pulp (MDC) and grease-proof pulp (GP) after alkaline hydrolysis, measured by three methods (Al, A2 and A3). Add-on (%) in grafting and yield in hydrolysis (YH in %) characterize the samples.

The production of graft copolymers from an initial polymer containing carbon-chlorine bonds, Et2AlQ and a monomer sensitive to cationic polymerisation seemed until recently the best indirect proof of Kennedy s initiation scheme ... 

The reaction scheme for graft copolyelectrolyte synthesis by free radical copolymerization according to the macromonomer technique is shown in Scheme 15. Besides the aspect of how to control the constitution of the graft copolyelectrolyte, suitable characterization techniques for unequivocal proof of the attained copolymer structure will also be elucidated. The synthesis, characterization and properties of the inversely structured poly(acrylic acid)-g-polystyrene graft copolymers it are covered in another article in this volume [178]. 

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