Polymers with a phosphorus

An overview of the synthesis and characterization of a unique class of polymers with a phosphorus-nitrogen backbone Is presented, with a focus on poly(dichloro-phosphazene) as a common Intermediate for a wide variety of poly(organophosphazenes). Melt and solution polymerization techniques are Illustrated, Including the role of catalysts. The elucidation of chain structure and molecular weight by various dilute solution techniques Is considered. Factors which determine the properties of polymers derived from poly(dichlorophos-phazene) are discussed, with an emphasis on the role that the organic substituent can play In determining the final properties. 

Vinyl and Acrylic Polymers. Vinyl and acrylic polymers containing phosphorus are prepared from a phosphorylated monomer or by treating the polymer with a phosphorus compoimd. 

With a phosphorus content of 7.9%, PCP showed FR behavior mainly in oxygenated polymers. This is in agreement with the well-known fact that phosphorus compounds are more effective in oxygenated polymers in bringing out flame retardancy than in other polymers [177]. Thus, Table 10 shows that at 20% loading, PCP... 

For polyester, the reported work82 done in Sichuan University of China, involves adding MMT clay in a copolymer of poly(ethyleneterephthalate), which with a phosphorus-containing monomer could produce PET with higher thermal stability and char-forming tendency. However, fibers were not produced from this PET-nanocomposite polymers. 

UV spectroscopy shows that quaternary phosphonium ions are present but, of course, does not prove that they are joined to polymer chains. The authors fractionated their polymers with a THF/water solvent-non solvent combination. They had found that the model compound described above could be quantitatively separated from phosphorus free poly(methylenemalonie ester). After fractionation the phosphorus content fell, but when the molecular weight was determined by vapour pressure osmometry, it was found that there was approximately one phosphonium group per chain. The absorption coefficient of the model compound was used to calculate the phosphorus content of the product. 

Isomerlzed unit took place during the polymerization. A polymer sample having a molecular weight of 3400 was prepared. It melted at 269 C and decomposed at 465°C. This Is the first example of an electrophilic ring-opening polymerization of cyclic phosphorus(III) monomer that yields a polymer with a clear-cut structure. 

A side reaction involving incorporation of the phosphorus moiety into the polymer backbone is unlikely to occur because no phosphoric acid has been detected upon oxidation of the polymer with a mixture of sulfuric acid and nitric acid. 

Polymers with a variety of chemical, physical, and biological properties can be produced by varying the side groups attached to the phosphorus in the polymer backbone. Different polymers are usually produced by performing substitution reactions on the base polymer, poly(dichlorophosphazene), for example ... 

Philip S, Keshavarz T, Roy I (2007) Polyhydroxyalkanoates biodegradable polymers with a range of applications. J Chem Technol Biotechnol 82 233-247 Pierce L, Schroth MN (1994) Detection of pseudomonas colonies that accumulate poly-beta-hydroxybutyrate on Nile blue medium. Plant Dis 78 683-685 Pijuan M, Casas C, Baeza JA (2009) Polyhydroxyalkanoate synthesis using different carbon sources by two enhanced biological phosphorus removal microbial communities. Process Biochem 44 97-105... 

Ouchi Y, Morisaki Y, Ogoshi T, Chujo Y (2007) Synthesis of a stimuli-responsive P-chiral polymer with chiral phosphorus atrans and azobenzene moieties in the main chain. Chem Asian J 2 397-402... 

Red phosphorus can be handled by encapsulating it in a thermosetting polymer with a dust suppressant, but for safety reasons it is usually supplied as a masterbatch for compounding by conventional means. The raw element is susceptible to ignition by sparks or by overheating, although it is not spontaneously flammable like the white variety. If exposed to moisture, it releases toxic phosphine that tends to be converted to phosphate. Light coloured products cannot cmrently be achieved with red phosphorus flame retardant additives. 

McWilliams AR, Manners I (2004) Polythionylphosphazenes inorganic polymers with a main chain of phosphorus, nitrogen and sulfiir(VI) atoms. In Gle-ria M, De Jaeger R (eds) (2004) Phosphazenes - a world-wide insight. Nova Science, New York pp 191-208... 

Wang Chun Shan, and Lin Ching Hsuan. Properties and curing kinetic of diglycidyl ether of bisphenol A cured with a phosphorus-containing diamine. J. Appl. Polym. Set 74 no. 7 (1999) 1635-1645. 

The use of cyclic voltammetry has already been mentioned in the characterizations of nickel(II) complexes with nitrogen- and phosphorus-donor ligands and of ruthenium(II) terpyridine bipyridine complexes with a phosphorus(III) ligand.Similarly, it has been used in the characterization of bis(diphenylphosphinomethyl)amino ligands and their Ni(II) and Pd(II) complexes. " A novel electrochemical sensor for detection of Dimethoate insecticide, and other similar organophosphates (OPs), based on a thin film-imprinted polymer, has been produced using electrodeposition of silver nanoparticles and electropolymerisation controlled by cyclic voltammetry scans " and more details are given later under sensors and biosensors. 

Levchik, S.V. Camino, G. Costa, L. Luda, M.P. Mechanistic stndy of thermal behaviour and combustion paformance of carbon fibre-epoxy resin composites fire retarded with a phosphorus-based curing syston. Polym. Degrad. Stab. 1996,54, 317-322. 

The cyclic phosphoramidites 45a (28) and 45b, initiated by alkyl halides (R X), undergo cationic polymerization by M-A rearrangement, giving polymers containing tetracoordinated phosphorus (46). In the anionic polymerization initiated by ButoK, no M-A rearrangement was observed and polymers with tricoordinated phosphorus 47 (poly-28) were obtained. 

---