Design of multiple flame-retardant polymers

Two polyphosphonates having multiple flame-retardant actions were synthesiz ed by interfacial polycondensation of a bisphenol and dichlorophenylphosphi ne oxide using cetyl trimethyl ammonium chloride as a phase transfer cataly st (PTC) at 0 degreesC. The polyphosphanates thus prepared were characteriz ed by viscometry, elemental analysis, IR, H-1-NMR, P-31-NMR, and X-ray diff raction studies. These polymers are highly soluble in polar solvents such a s DMF, DMAc, DMSO, etc., as well as in chlorinated hydrocarbon solvents suc h as CH2Cl2, CHCl3, etc. The thermal study of polymers was carried out by T GA and DTA analyses. The flammability of the polymers was studied by the li miting oxygen index measurements. The polymers are self-extinguishing, and begin to lose weight at around 252 degreesC. (C) 2001 John Wiley & Sons, In c.