THE REACTIONS OF SULPHUR WITH CHLORINATED PHENOLS

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Abstract
Reactions of sulphur with chlorinated phenols and 2,4-dichloroanisole in open vessels under nitrogen and at high temperatures were investigated with the aim of preparing thermostable polymers. The results indicate that the chlorine atom in 4-chlorophenol is very reactive, whereas that in 2-chlorophenol is unreactive. This explains why the chlorine content of the polymers is as high as 10–15%, and also suggests that the initial reactions occur in the 4-position, after which the ortho-chlorine and the hydrogen atoms react with thermally activated sulphur. The ratio of sulphur to monomer and the reaction time, temperature and pressure had definite effects on the reactions. The results were compared with earlier results obtained with sealed reaction ampoules. The products were of low or high molecular weight, depending on the above conditions. The sulphur content of the products was 20–30% and the softening points varied with the molecular weight. When the products were methylated the softening points became lower. Dimers and trimers were present in the ether-soluble fractions. Investigations by GLC-MS suggested that they were precursors for the polymers.