Caractérisation physico‐chimique d'un polymère phosphore

A mixture, probably composed of a poly(chlorotrimethylsilyloxy)phosphazene and a compound with the general formula H2Cl2NOP (inactive toward THF) was used to initiate the polymerization of tetrahydrofuran. The resulting polymer (PTHFP) contains phosphorus associated with nitrogen, as assessed by IR, 31P and 1H NMR spectroscopy. The thermal stability of PTHFP, observed by thermogravimetry, was found to be much higher than that of polytetrahydrofuran (PTHF). At the end of its decomposition a solid residue remains, which was identified as a poly(phosphazene oxide) (PNO)n. The combustion behaviour is also modified in that the cool flame combustion area is raised up in the pressure-temperature coordinates. In addition, the disappearance of the so-called secondary cool flame (SCF) phenomenon is in favour of the heterogeneous action of the phosphorus derivatives during the inhibition of combustion at higher temperatures. The thermochemical analysis (DSC-Rheovibron) shows the existence of a semi-cristalline structure proportional to the amount of phosphorus introduced into the PTHF chain. The glass transition temperature of PTHFP was found to be slightly higher than that of PTHF without any apparent relation to their structures. The same conclusion arises from the viscoelastic measurements.