Branched Co polymers

In the macromonomer approach, polymeric chains (of monomer Mi) end-functionalized with a vinyl group are homopolymerized (with Mi) or copolymerized (with M2) to produce branched (co)polymers. Thus, poly(ethylene glycol) methyl ether methacrylate (CJien et al., 2003) and poly(dimethyl siloxane) methacrylate (Shinoda and Matyjaszewski, 2001) have been homo- or copolymerized to yield graft (co) polymers with the corresponding pendant chain. 

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Multiarm star (co)polymers can be defined as branched (co)polymers in which three or more either similar or different linear homopolymers or copolymers are linked together to a single core. The nomenclature that will be used follows the usual convention ... 

Chen, Q. et al, Branched co-polymers of histidine and lysine are efficient carriers of plasmids. 

The completely cationic synthesis of comb or graft copolymers have yet to be realized [103]. However, numerous backbone polymers, branches and macromonomers have been prepared separately via cationic polymerization and these have been combined with other grafting and polymerization processes to prepare (co)polymers that cannot easily be prepared otherwise [103]. 

An important group of surface-active nonionic synthetic polymers (nonionic emulsifiers) are ethylene oxide (block) (co)polymers. They have been widely researched and some interesting results on their behavior in water have been obtained [33]. Amphiphilic PEO copolymers are currently of interest in such applications as polymer emulsifiers, rheology modifiers, drug carriers, polymer blend compatibilizers, and phase transfer catalysts. Examples are block copolymers of EO and styrene, graft or block copolymers with PEO branches anchored to a hydrophilic backbone, and star-shaped macromolecules with PEO arms attached to a hydrophobic core. One of the most interesting findings is that some block micelle systems in fact exists in two populations, i.e., a bimodal size distribution. 

In the case of branched polyethylene the danger that staining may affect the crystal surfaces is considerably increased. However, under very careful staining conditions the experimental results for a large number of different polyethylene co-polymers have been found to be very reproducible and consistent. 

Baney and co-workers (iO) used the known Si-Si and Si-Cl bond redistribution of methylchlorodisilanes to prepare poly(methylchlorosilane)s. Pyrolysis of these branched polysilane polymers gives nearly stoichiometric amounts of silicon carbide (equation 6). 

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