Functional polyphosphazenes

The design of functionalized polymers with a specific utilization is seen in new polysiloxanes used by Zeldin (p. 199) as phase transfer catalysts. Novel functional polyphosphazenes have been reported as well by Allcock (p. 250). The introduction of transition metal cyclopentadienyl, metal carbonyl and carborane moieties into polyphosphazene macromolecules is representative of truly novel chemistry achieved after careful model studies with corresponding molecular systems. 

Living" polymer end units initiate more of the same monomer, or a different phosphoranimine monomer, or react with a functional chain terminator to give an end-functionalized polyphosphazene. 

Since the procedure for the formation of macroinitiator by using 21, mentioned in the synthesis of block copolymers of polyphosphazene and PEG, enabled the synthesis of monofunctional polyphosphazenes [288], monoallyl functional polyphosphazene was prepared and underwent hy-drosilylation with dihydride-terminated poly(dimethylsiloxane) to pro-... 

Polyphosphazenes with simple alkyl and aryl substituents directly attached to the backbone by P-C linkages can be prepared by the condensation polymerization of N-silylphosphoranimine precursors. These simple polymers can then be converted to a variety of functionalized polyphosphazenes by derivatization reactions. In this paper, the synthesis and characterization of some derivatives of poly(methylphenyl-phosphazene), [Me(Ph)P=N]and the copolymer, [Me(Ph)P=N]j [Me2P=N)y, are discussed. These polymers include grafted copolymers, water soluble carboxylated polymers, and polymers with silyl, vinyl, alcohol, ester, ferrocene, phosphine, thiophene, and/or fluoroalkyl groups. 

Figure 3.5 Microsphere formulation through crosslinking of PCPP with multivalent ions. Reproduced with permission from Sandra Wilfert in Novel and Functional Polyphosphazenes for Biomedical Applications, Johannes Kepler University, Linz, Austria, 2014 [PhD Thesis]. 2014, Johannes Kepler University [61]...

Figure 5.15. Ring-opening polymerization of hexachlorocyclotriphosphazene, and subsequent reactions to yield functionalized polyphosphazenes.

In a follow-up study, Lvov et al. [46] prepared membranes of good physicochemical characteristics from blends of sulfonimide functionalized polyphosphazene and PVDF. For example, a membrane prepared from poly-... 

Recently, an interesting modified postsulfonation procedure was developed by He et al. to prepare a series of perfluoroalkyl sulfonic acid-functionalized polyphosphazenes (PSA-P) [94]. A polymer precursor, poly[(4-bromophenoxy) (phenoxy)phosphazene], was synthesized first before reacting with potassium... 

FIGURE 7.22 Synthesis of sulfonimide-functionalized polyphosphazenes. (Reprinted with permission from Hofmann, M.A., Ambler, C.M., Maher, A.E., Chalkova, E., Zhou, X.Y., Lvov, S.N., and Allcock, H.R., Synthesis of polyphosphazenes with sulfonimide side groups. Macromolecules, 35, 6490. Copyright 2002 American Chemical Society.)... 

FIGURE 7.23 Synthesis scheme of azole-functionalized polyphosphazenes. (Hacivelioglu, R, Oezden, S., Celik, S.U., Yesilot, S., Kilic, A., and Bozkurt, A., Azole substituted polyphosphazenes as non-humidified proton conducting membranes, J. Mater. Chem., 21, 1020-1027, Copyright 2011. Reprinted by permission of The Royal Society of Chemistry.)... 

---