The thermal stability of phosphorylated poly(acenaphtylene) has been s
tudied and compared with that of the unmodified poly(acenaphtylene). T
he results indicate that the introduction of phosphorus into the polym
eric chain gives rise to a decrease in the thermal stability this effe
ct being related with the phosphorous content in the sample. Some diff
erences have been found in the behaviour of low molecular weight poly(
acenaphtylene) with respect to that of high molecular weight.