Poly tris phosphazene

Considering first Table 5, it can be seen that Tg values for the reported poly(organophosphazenes) spanned from very low (-105 °C in the case of poly[bis(n-butoxy)phosphazene]) up to very high (-1-220 °C for poly[tris(2,2 -dioxy-l,T-binaphthyl)phosphazene]), covering almost all the intermediate temperatures between these two limits. Low TgS are indicative of very high torsional freedom of the polyphosphazene chain, which is manifested clearly when flexible substituents of reduced bulkiness are used in the substitution... 

Thermal degradation poly(tri-fluoroethoxy-phosphazene) (homopolymers)... 

As can be seen, the first example of phosphoranimine polymerization process was proposed by E. P. Flindt and H. Rose [314] in 1977 for tris(trifluoroethoxy)-AT-(trimethylsilyl)phosphoranimine, which could be polymerized to poly[bis-(trifiuoroethoxy)phosphazene] (MW 4000-10,000) by simple heating at 200 °C. 

O4CSFS, Cesium fluorine sulfate, 24 22 04Fi2N3P3C,oHi4, Poly[2,2-dimethyl-4,4,6,6-tetrakis(2,2,2-trifluoroethoxy)catenatri-phosphazene-l,6-diyl], 25 67 04F,2N3P3SiCi3H22, Poly[2-methyl-4,4,6,6-tetrakise(2,2,2-trifluoroethoxy)-2-[(tri-methylsilyl)methyl]catenatriphospha-zene-l,6-diyl], 25 64... 

Poly[P-tris(trifluoroethoxy)-N-trimethylsilyl] phosphazene carbon dioxide HPPE 392... 

A critical advantage of phosphazene materials is the ability to fine tune hydrophilicity through pendant group selection. Another method demonstrated that the the same type of tuning can be performed by formation of tri-block copolymers. A synthesis of a MEEP/poly(propyleneglycol) has been reported using phosphoranimine condensation to form the phosphazene portion. ... 

Phosphoranimine condensation was discussed in recent reviews and mechanistic studies. A step-wise progression is shown in Scheme 12. Poly (propyleneglycol) (PPG), terminated with amine groups, reacts with bis-tiifluormethylbromo-N-trimethylsilylphosphoranimine to form the PPG-phosphazene adduct. Oligomeric poly(dichlorophosphazene) is formed from the ambient temperature condensation of tris-trifluoroethoxy-N-trimethyl-... 

PEO Poly(ethylene oxide) MEEP —(N=P(0C2H40C2H40CH3)2) Poly(bis-(methoxy ethoxy ethoxide) phosphazene PPO poly(propylene oxide). Dimensionality of the conduction mono-(lD), bi-(2D) or tri-(3D) dimensional. E activation energy of pj RT room temperature total conductivity electronic conductivity E band gap. 

Lora et al, did try to enhance the biocompatibility of poly[bis(trifluoroethoxy)-phosphazenes] (PTFP) and poly[bis(phenoxy)phosphazenes] (PPP) by grafting different side groups on the polymer surface (Figpme 28). Graft copolymerization w ith dimethylaminoethylmethacrylate (DMAEM) onto the polyphosphazene surfaces highly enhances their biocompatibility. Subsequent heparinization has a negative effect, which is more appreciable with the PPP-based samples (Lora et al., 1991). Surface modification of poly[bis(trifluoroethoxy)phosphazene] with... 

A multi-gram scale preparation of hydrophobic poly(bis 2,2,2-tri-fluoroetho)y)-phosphazene (158) with low PDI (<1.15) at high conversion (75-99%) has been developed. The molecular weight of the polymer can be controlled by varying the initiator (H2O) to monomer ratio (Scheme 20). ... 

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