Poly methylphenylphosphazene

three-necked flask equipped with a nitrogen inlet, a mechanical stirrer, and a pressure equalizing addition funnel is charged with 

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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). 

In poly(methylphenylphosphazene), [Ph(Me)P=N] 58, both the phenyl and methyl substituents are potential sites for formation of derivatives [65]. Deprotonation of ca. half of the methyl substituents on this polymer was carried out in THF at — 78 °C using n-BuLi. On treatment of the intermediate polymer anion with ferrocenyl ketones and subsequent quenching with a mild proton source, phos-phazenes 59 containing the OH functional group were prepared. The amount of substitution, determined by NMR and elemental analysis, was found to be 45 and 36%, respectively, for polymers 59a and 59b (Scheme 10-27). For these substituted polymers was 187000 and 154000, respectively, and no degradation of the parent polymer occurred. 

Me, Ph, CjH FeCp) A series of fluorinated alcohol derivatives were also prepared.The addition of (Me2SiO)3 followed by Me3SiCl or further addition of cyclosiloxane gives slloxane or poly (slloxane) substituents. The addition of CO2 to the lithiated intermediate gives a carboxylate function which can be converted to the free acid or esterifled with p-nitrobenzylbromide. The addition of styrene to [NP(CH2Li)Ph] causes anonic polymerization of styrene and thus the formation of poly(methylphenylphosphazene)-graft-polystyrene copolymers. 

POLY(DIMETHYLPHOSPHAZENE) AND POLY(METHYLPHENYLPHOSPHAZENE) PoIy[nitrilo(dimethylphosphoranyIidyne)] and PoIy[nitrilo(methylphenylphosphoranylidyne)] ... 

Poly(methylphenylphosphazene) is soluble in CH2CI2, CHCI3, benzene, and THF, and is insoluble in H2O, hexane, and acetone. Molecular weight... 

Polyphosphazenes with ferrocenyl substituents 35 have also been synthesized via the functionalization of poly-(methylphenylphosphazene) and related polymers by means of a deprotonation-electrophilic addition strategy (e.g., see Equation (10)). This versatile reaction sequence has yielded materials with, for example, degrees of substitution of 45% and 36% for polymers 35 (R = H and Me), respectively. The molecular weights of the polymers were M = Z.O x 10 and 1.5 x 10 for 35 (R = H and Me), respectively (with PDI values of 1.4-2.0). The glass transition temperatures increased in comparison with the unsubstituted polymer (Tg = 37°G) for 35 with values of 92 °C (R = H) and 87 °G (R = Me). 

Two series of new polyphosphazenes were prepared by derivatization of preformed poly(methylphenylphosphazene), [Me(Ph)PN]p. This Involved Initial deprotonatlon of part of the methyl substituents with n-BuLi followed by treatment of the intermediate anion with carbon dioxide or with fluorinated aldehydes or ketones. With appropriate workup procedures, either carboxylic acid, ester, carboxylate salt, or fluorinated alcohol derivatives were obtained. These reactions and the characterization of the products are discussed In this paper. Related derivatization reactions are also discussed. 

The poly(alkyl/arylphosphazene)s prepared by the above method have moleeular weights between 50,000 to 200,000 with a polydispersity index of 2.0. The solubility of these polymers seems to depend on the type of substituents present on the phosphorus. Thus, [NPMe2]n is soluble in di-chloromethane, chloroform, ethanol as well as a 1 1 mixture of THF and water. In contrast, [NPEtiJn is virtually insoluble in any organic solvent. However, upon protonation with weak acids [NPEt2] becomes soluble. It has been speculated that protonation destroys the crystallinity of this polymer and enables its solubility. Poly(methylphenylphosphazene), [NP(Me)(Ph)]n is also soluble in a large number of organic solvents such as chlorinated hydrocarbons as well as THF [33]. 

The polymerization is in fact a chain-growth reaction and allows access to high molecular weight polyphosphazenes such as poly(dimethylphosphazene) and poly(methylphenylphosphazene) (2). Methyl deprotonation/substitution of these polymers as well as electrophilic aromatic substitution of the phenyl substituents in poly(methylphenylphosphazene) have been developed as versatile strategies for the derivatization of both of these polymers (eq. 3) (3). 

Poly(methylphenylphosphazene) can be derivatized through either deprotonation/substitution reactions at the methyl group or electrophilic aromatic substitution of the phenyl group. These reactions have been used to prepare a variety of new polyphosphazenes with all functional groups attached to the polymer backbone by direct P-C bonds. The synthesis and characterization of several of these new... 

Photophysics and Photochemistry of Poly(methylphenylphosphazene) and Poly (methylphenylphosphazene) - o -poly styrene... 

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