Styrene, graft copolymers with poly

The macromonomers thus obtained exhibit molecular weights as low as 1000. They were copolymerized with monomers such as styrene and butyl acrylate whereby graft copolymers with poly(vinyl chloride) grafts were obtained. 

The graft copolymers with poly (H-1) arms have multiple carbon—halogen bonds that can initiate copper-catalyzed radical polymerization to give highly branched dendrigraft polymers.432 The products with styrene or nBMA had relatively narrow MWDs because each chain was prepared by living polymerization. 

In addition to providing fully alkyl/aryl-substituted polyphosphasenes, the versatility of the process in Figure 2 has allowed the preparation of various functionalized polymers and copolymers. Thus the monomer (10) can be derivatized via deprotonation—substitution, when a P-methyl (or P—CH2—) group is present, to provide new phosphoranimines some of which, in turn, serve as precursors to new polymers (64). In the same vein, polymers containing a P—CH group, for example, poly(methylphenylphosphazene), can also be derivatized by deprotonation—substitution reactions without chain scission. This has produced a number of functionalized polymers (64,71—73), including water-soluble carboxylate salts (11), as well as graft copolymers with styrene (74) and with dimethylsiloxane (12) (75). 

Such hydrophilic macromonomers (DPn=7-9) were radically homopolymer-ized and copolymerized with styrene [78] using AIBN as an initiator at 60 °C in deuterated DMSO in order to follow the kinetics directly by NMR analysis. The macromonomer was found to be less reactive than styrene (rM=0.9 for the macromonomer and rs=1.3 for styrene). Polymerization led to amphiphilic graft copolymers with a polystyrene backbone and poly(vinyl alcohol) branches. The hydrophilic macromonomer was also used in emulsion polymerization and copolymerized onto seed polystyrene particles in order to incorporate it at the interface. 

Due to the low solubility of poly(4-vinyl pyridine) in THF, a block copolymer of 4-vinyl pyridine with styrene has been used (Mn = 13,500). Living polyTHF (Mn = 3,300) has been grafted with efficiencies higher than 95 %. About 20 % of the pyridine units were consumed, yielding a graft copolymer with 80% polyTHF. No further data on this product were reported. 

A second approach is the copolymerization of vinyl, or methacryloyl group containing backbone chain of poly(si 1sesqui-oxanes) with vinyl monomers such as styrene, methyl methacrylate, and acrylonitrile by a radical initiator. At low concentration of monomers ( less than 10 vjt% ), soluble styrene-grafted copolymers have been indeed obtained. 

Pyrrole is a very reactive monomer and the evidence suggests that its homopolymers and copolymers are crosslinked materials the random copolymer with 95 mole% styrene units is insoluble and the PMMA graft copolymer with 1.4% pyrrole is soluble through a 0.02 pm filter. There is no confirmation in the literature of the report that doped or neutral poly(3-alkylpyrroles) are soluble. 

Abbreviations HIPS, high-impact polystyrene ABS, acrylonitrile-butadiene-styrene graft copolymer EPDM, ethylene propylene-diene copolymer CTBN, carboxyl terminated butadiene nitrile telomer M = 5000 g/mol) PC, polyearbonate SBS, styrene-butadiene-styrene triblock copolymer SIS, styrene isoprene styrene tribloek copolymer SEBS, SBS with hydrogenated center block PU, segmented (block copolymer) polyurethanes PDMS, poly(dimethyl siloxane) FIFE, polytetralluoroethylene. 

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