Macromers graft copolymerization

A polystyrene with a functionality such as a methacrylate group copolymerized with a mixture of ethyl and butyl acrylate should yield a graft structure meeting the criteria of a thermoplastic elastomer as shown in Figure 13. The data in this figure show that as the MACROMER content is increased, the tensile... 

An elegant alternative to living polymerization for the preparation of block polymers is to use functionalized Grignard initiators. The polymerization of methyl methacrylate to isotactic (in toluene at — 78"C) or syndiotactic polymers (in THF at — llO C) can be initiated by o-, m-, and p-vinylbenzylmagnesium chloride. The polymers had a low polydispersity and contained one vinylbenzyl group at the chain end, by H-NMR. The poly(methylmethacrylate) macromers thus obtained were polymerized or copolymerized with styrene to give graft and block polymers of controlled architecture [50,51]. 

Macromers by Controlled Initiation. New and unique graft copolymers can be prepared by copolymerizing macromers (macromolec-ular monomers) with conventional monomers. The synthesis of poly(butyl acrylate- -isobutylene), i.e., the first graft synthesis that involves carbocationic controlled initiation, has recently been accomplished by the following route (9) ... 

An alternate route to graft copolymers is by synthesis of macromolecules possessing exactly one polymerizable group in the chain and their subsequent polymerization, i.e. grafting through. Such reactive polymers are macromolecular monomers, i.e. Macromers as abbreviated by Milkovitch 159), who was the first to call the attention of the scientific community to the importance of this field although macromonomers have been prepared and copolymerized as early as 1962 160). 

Ring-opening, cationic copolymerization of the macromers with 2-phenyl-2-oxazoline produced graft copolymers consisting of a N-benzoylethyleneimine backbone and poly(ethylene oxide) grafts. 

Table 3 shows that in the copolymerization of macromer with ethylene oxide different types of catalyst attained different grafting efficiencies, which was calculated by the following equation ... 

Figure 4. Graft copolyma formed by copolymerization of TBCS with a macromer.

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