Grafting-from polymerization

Witte P, Menzel H (2004) Nickel-mediated surface grafting from polymerization of alpha-amino acid-N-carhoxyanhydrides. Macromol Chem Phys 205 1735-1743... 

The metallocene catalyst with cationic nature and spatially opened active site provides favorable condition for the incorporation of p-alkylstyrene (p-ms) to polyolefins. The p-ms groups can be easily metallated to produce "stable" polymeric anions for graft-from polymerization. With the coexist of anion-polymerizable monomers, we have prepared many graft copolymers, such as PE-g-PS, PE-g-PMMA, PE-g-PAN, PP-g-PS, PP-g-PB, PP-g-PI and PP-g-PMMA. 

Table 4. A summary of the anionic graft-from polymerization reactions by using lithiated poly(ethylene-co-p-methylstyrene) as initiator...

Table 4 summarizes the reaction conditions and the experimental results. Overall, the experimental results clearly show a new class of PE graft copolymers which can be conveniently prepared by the tranformation of metallocene catalysis to anionic graft-from polymerization. 

In grafting from this limitation is overcome by polymerizing the polymer directly on the surface. The polymerization is carried out step-by-step after initiation by eligible chemical groups which are called initiators I. The scheme for a grafting-from polymerization is shown in Fig. 10.11. It is also called surface-initiated polymerization or SIP. 

Figure 10.11 Scheme for grafting-from polymerization. I is an initiator, M a monomer and X an end-group for further coupling reactions. 

Figure 6.21 Schematic description of the steps used for fabricating hollow capsules (coated inside with potassium persulfate initiator) and grafting-from polymerization of styrene sulfonate (SS) inside the capsules. (After Choi et al., 2005.)...

Chapter 6), grafting-from polymerization and polymer brushes (Chapter 6), living controlled radical polymerization (Chapter 6), metallocene-based Ziegler-Natta catalysts (Chapter 9), immobilized metallocene catalysts (Chapter 9), and oscillating metallocene catalysts (Chapter 9). 

As shown above, hybrid structures bearing amylose blocks can be synthesized by covalent attachment of primer recognition units for phosphorylase and subsequent enzymatic grafting from polymerization. Following the same route we are currently synthesizing hybrid materials bearing (hyper)branched polysaccharide structures as shown in figure 6 with the described tandem reaction of two enzymes. 

Figure 1.2 Functional polymer layers on surfaces produced with (a) grafting to and (b) grafting from strategies, (a) In grafting-to processes, preformed polymer chains containing a linker group (B) are chemically bound to anchor groups (A), (b) In grafting-from, polymerization of a monomer (M) is started from initiators (I) bound to the surface.

Durand N, Boutevin B, Silly G, Ameduri B (2011) Grafting From polymerization of vinylidene fluoride (VDF) from silica to achieve original silica-PVDF core-shells. Macromolecules 44(21) 8487-8493... 

Concerning grafting techniques, in GTP acrylates are much more reactive than methacrylates. Thus 2-methacryloxyethyl acrylate in the presence of ZnBr2 is polymerized exclusively to a polymer with pendant methacrylate groups capable of radical and GTP grafting from polymerizations [73]. Irradiation teehniques have often been employed... 

Polybenzimidazoles with grafted ionomer side chains grafting-through and grafting-from polymerization of vinylphosphonic acid onto PBI [38 ]. 

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