Polymers with pendent functional groups. V. Thermooxidative and thermal behavior of chloromethylated polysulfones

The first step of the thermooxidative and thermal decomposition of some chloromethylated polysulfones (CMPSF) with various degrees of substitution has been studied by thermogravimetry (TG) and thermal volatilization analysis (TVA). A step occurring at lower temperatures 260-370 degrees C is particular for halomethylated polysulfones because the polysulfone (PSF) is thermally stable in this temperature range (its first decomposition step occurs from 400 to 550 degrees C). The higher the degree of substitution, the lower the degradation temperature and a better separation of the processes was found. The thermal decomposition products collected were analyzed by IR spectroscopy and elemental analysis. According to our TG and TVA results and literature data, it call be proposed that -CH2Cl groups react at low temperatures giving cross-linked polymer and gas or liquid products. The thermal characteristics of this process depend on the chlorine content of the sample and explain undesirable cross-linking that could take place during the synthesis of the chloromethylated polysulfones. (C) 2000 Elsevier Science Ltd. All rights reserved.