Polyphosphazene derivatives

Polyphosphazenes are inorganic macromolecules containing a phosphorus-nitrogen backbone with each phosphorus atom having two pendant side groups. Polyphosphazene derivatives were prepared by nucleophilic displacement of either fluoroalkoxy or chloro substituents using a nucleophile that consisted of a ketal alkoxide, which was subsequently oxidized using concentrated nitric acid or an azido alkoxide. 

Additional biodegradable and thermosensitive polyphosphazenes derivatives, (I), were prepared by the author [1] in an earlier investigation. Thermosensitive cyclotriphosphazene analogues were also prepared by Sohn [2]. 

Helicity induction was also realized for polyphosphazene derivative 109 using R) -1 -phenethylamine (110) as the chiral additive.193... 

PEG, dextran, silica, gelatin, etc., and non-biodegradable polymers, such as PMMA, polyacrylamide, polystyrene, poly cyanoacrylate, polyphosphazene derivatives, etc., are being explored in the field of drug and gene delivery (Park et al., 2009). 

Single-handed helicity induction was also achieved in gels and films of polyphenylacetylene derivatives. Gels obtained by copolymerization of (4-carboxyphenyl)acetylene with a bis(phe-nylacetylene) or by cross-linking of 168 responded to chirality to nonracemic amines in DMSO and alkaline water. Compound 174 formed an optically active gel upon complexation with optically active bis (amino acid)s. A cast film of 168 exhibited ICD in response to the chirality of liquid and solid chiral amines. Polydiacetylenes with a 4-carboxyIphenyI functions also showed ICD in the presence of optically active amines in dispersion and in the solid state. Helicity induction was also realized for polyphosphazene derivative 185 as (P)-phenethylamine as the chiral additive. ... 

The biomedical applications of polyphosphazene derivatives and phos-phoiylated polymers will not be covered in this review, although... 

The R group can be an alkoxy, aryloxy, amino, alkyl, heterocyclic ring or an inorganic or organometallic unit. Allcock and co-workers were the first who did study extensively the synthesis of poly[(organo)phosphazene] derivatives. Most polyphosphazene derivatives are prepared starting from a precursor polymer, poly[(dichloro)phosphazene]. A variety of polymers with variable properties can be prepared by nucleophilic displacement reactions (Allcock, 1972, 1979, 1986) (Figure 2). 

USGS. Some of the most useful polyphosphazene derivatives are fluoroalkoxy derivatives, and amorphous copolymers are very useful as flame-retardant, hydrocarbon-solvent, and oil-resistant elastomers and have found aerospace and automotive applications. Pol5miers such as the amorphous comb polymer poly[bis(methoxyethoxyethoxy)phosphazene] (8) are of considerable interest as components of polymeric electrolytes in battery technology (1). 

Optical Devices. Of most interest in this application are those studies related to the nonlinear optical effects in polyphosphazene derivatives bearing aromatic azo imits (217-219) and the photorefractive effect with pol5q)hosp-hazenes bearing carbazolyl substituents (220). Possible applications include optical switches, frequency doublers for lasers, holographic data storage, and real-time image processing. 

An interesting polyphosphazene derivative, sulfonated poly[bis(2-phen-oxyethoxy)phosphazene], was reported by Paulsdorf et al. [35] (Fig. 7d). Living cationic polymerization of CI3P = NSi(CH3)3 monomer was used to obtain PDCP, which was reacted with 2-phenoxyethanol. The aryl substituents... 

Polyphosphazenes containing amino acid ester side groups were the first biodegradable polyphosphazenes synthesized. These polyphosphazene derivatives are... 

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