Grafting reaction of macromolecules

A. Grafting Reaction of Macromolecules Having 4-Tolylcarbamoyl Pendant Group... 

Hasegawa R, Doi M (1997) Dynamical mean field calculation of grafting reaction of end-functionalized polymer. Macromolecules 30 5490-5493... 

In conclusion, the light-induced grafting reactions of organic macromolecules onto pho hazene polymer films is a process that depends on several factors, i.e. the type of POP used as grafting support, the characteristics and the concentration of the exploited monomers, the type of photoinitiator, the swelling of the phosphazene substrate, etc. The accurate control of these parameters is mandatary in order to prepare phosphazene grafted copolymers of predictable characteristics. 

The synthetic methods of macromolecules having an active pendant group include (1) the transformation reactions of polymer and copolymers, and (2) polymerization and copolymerization of functional monomers having active pendant groups. The macromolecules, either in the shape of film or microbeads, can be used as the substrate. As we have mentioned previously, the rate of polymerization initiated with the Ce(IV) ion redox system is much faster than that initiated by Ce(l V) ion alone, as expressed in / r 1. Therefore, the graft... 

Higaki, Y Otsuka, H. Takahara, A. Dynamic formation of grafted polymers via radical crossover reaction of alkoxyamines. Macromolecules 2004, 37, 1696-1701. 

Carbanions can react with Cl in PVC macromolecules [295] and with the ester group of PMMA [284]. The rates of the two reactions are probably not very different by the addition of a-methylstyrene tetramer dianion to a PVC + PMMA solution, the copolymer poly(vinyl chloride)-gro/ir-poly-(methyl methacrylate) was obtained [296]. Macrocations formed by the reaction of strong acids with polyalkenes (see Chap. 3, Sect. 3.2) react with polyethers (polysiloxanes) yielding graft and block copolymers, e. g. poly(propylene)-0ra/ir-poly (oxyethylene) [297], poly(propylene)- /ocA -... 

In ABS, because the BR units are more photosensitive than the PS units, they are photooxidized in the first steps of the reaction. The radicals which are formed can attack the neighboring PS units. Moreover, the grafted sites of the PS macromolecules are the starting sites of an additional route of photooxidation of the PS units. Therefore, the kinetics of oxidation of the copolymer ABS are twice as fast as expected on the basis of only addition of the photooxidation rates of the two polymers studied separately. 

Both types of reaction have been reported, however. The appearance of block or graft copolymers has been the usual type of evidence for Interaction of macromolecules and macroradicals. 

Doerffler and Patten have recently described a similar methodology for the formation of a less densely packed backbone where grafted polymers (macromolecules derived from only one monomer) were prepared strictly by ATRP [125]. The copolymerization of 4-acetoxymethyl- or 4-methoxymethylstyrene with styrene yielded a pendant functional macroinitiator with latent initiation sites . Transformation of the ester or ether to benzyl bromide substituents provided the alkyl halide necessary for the grafting reactions. The increased poly-dispersities observed above 20% monomer conversion were attributed to internal coupling reactions between the grafted chains. 

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