Cationic graft polymerization

Graft Polymerizations.—Cationic graft polymerizations may be classified under two principal headings (/) grafting onto reactions in which propagating macrocations are terminated on a substrate, and (h ) grafting from reactions in which the substrate is employed as a macro-initiator for cationic polymerization. 

Pan et al recently reported the preparation and characterization of polystyrene/graphite composites prepared by cationic grafting polymerization. Graphite/polystyrene composites were produced with cationic grafting... 

Recently, Spange et al. (19,20) have successfully achieved cationic graft polymerizations of vinyl ethers, vinyl furan, and cyclopentadiene onto silica, initiated by a stable ion pair formed from silanol and aiylmethyl halide, such as di(p-methoxy-phenyl)methyl chloride. The grafting of the polymer onto silica is proposed to take place via the propagation based on olefin insertion to a cation center being in a rapid equilibrium with the ion pair, as shown in Scheme 12.1.3. 

Tsubokawa et al. (44) have reported the grafting of polymeric cationic species of vinyl butyl ether or 2-methyl-2-oxazoline onto aminated silica particles via the termination. However, it is ordinarily difficult to apply the surface termination reac-... 

Richards, G. N., and E. F. T. White Graft polymerization on cellulosic materials. Part I. Cation-exchange membranes from paper and acrylic acid. J. Polymer Sci. C. No. 4, 1251 (1964). 

Plesh, P. H. Graft polymerization with cationic catalysts. Chem. and Ind. 1958, 954. 

Choi and co-workers [56] modified BC with cation-exchangeable acrylic acid units by UV graft polymerization. For this purpose, the BC was dried at 80 °C, immersed in methanol with benzophenone as a photoinitiator for... 

The time course of adhesion between two identical A A-dimethylpropyl acylamide (DMAPAA)-grafted PET films is shown in Fig. 32. The graft density was as low as 8/ig/cm2, because of the difficulty in surface graft-polymerization of this cationic monomer. As is seen, this cationic sur-... 

More detailed electrostatic interaction in aqueous media between two surfaces grafted with ionic polymer chains was measured with the use of AFM [100]. The AFM tip surface was modified by graft polymerization of a cationic monomer after being coated with a cyanoacrylate polymer. Figure 41 illustrates the plausible scheme employed in the experiment. A... 

Apart from reacting with the growing grafted chain macroradicals, the oxidant cations or the initiator radicals may cause decomposition of cellulose macroradicals formed at the first stage of oxidation. Taking into account the latter process, the rate of graft polymerization initiation may be described as follows62 ... 

Photolithography on the basis of the cationic graft-polymerization uses an inert polymer film containing a PAQ coated onto a wafer. Exposing the photoresist to the UV radiation generates acid on its surface, to which a vapor-phase silicon-containing monomer is grafted. RIE in O2 is used as a final step. ° ... 

Interest in this area was aroused after 1980. Three recent reviews summarize the research in this field (202-204). They also present the advantages of this synthetic method in comparison with other techniques for the synthesis of graft copolymers. Among radical, anionic, and cationic types of polymerization, cationic polymerization seems to be the most successful for the synthesis of polymerizable oligomers. 

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