Grafting Through - Copolymerization of Macromonomers

Graft copolymers made by living polymerization processes are often called polymer brushes because of the uniformity in graft length that is possible. The basic approaches to graft copolymers also have some analogies with those used in making block and star copolymers. 

The grafting through approach involves copolymerization of macromonomers. NMP, ATRP and RAFT have each been used in this context. The polymerizations are subject to the same constraints as conventional radical polymerizations that involve macromonomers (Section 7.6.5). However, living radical copolymerization offers greater product uniformity and the possibility of blocks, gradients and other architectures. 

ATRP has also been used to synthesize maeromononicrs subsequently used to make graft copolymers by conventional radical polymerization. Thus, low molecular weight PBA formed by ATRP was converted in near quantitative yield to the methacrylate ester (351) or the corresponding acrylate ester.612 

There have been several studies on the use of RAFT to form polymer brushes by polymerization or copolymerization of macromonomers 348-350. 

Systems examined include copolymerizations of 349 with MMA using RAFT agent 175,548,711 348 with AA using 2207 0 and 348 with 352 using 176.7 4 The latter copolymerization created a precursor for a grafting from reaction by ATRP using the bromoisobutyrate group as an initiator/34 

NMP of S with 346 as initiator gave PS with pendant oxazoline groups. Cationic polymerization of this macromonomcr gave a polyoxazolinc with PS grafts that retained the alkoxyamine functionality. ATRP with 156 as catalyst and ethyl 2-bromoisobutyrate (125a) as initiator has been used to prepare 

A number of reviews on dendronized polymers and their synthesis by various methods including radical polymerization of dendron macromonomers have 

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