Aromatic Polysulfides Poly arylene Sulfide s

The technically most important polysulfide is polythiophenylene or poly(p-phenylene sulfide), PPS. It is obtained by reacting sodium sulfide and p-dichloro-benzene in a polar solvent, for example, l-methyl-2-pyrrolidone at about 280°C under pressure. The mechanism of the reaction is very complex and cannot be described by a simple aromatic substitution. This synthesis requires special autoclaves and is therefore not suitable for a laboratory course (for an experimental procedure see Table 2.3). 

Because of the limited solubility of PPS - even at high temperature - the attainable molecular weights are relatively low (M = 1,000-20,000). 

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