Synthesis and characterisation of poly(arylene sulphides): Part 11. Preparation of poly(1,4‐phenylene sulphide) directly from bis(4‐bromophenyl) disulphide

Abstract

Abstract Reaction conditions for the preparation of poly(1,4‐phenylene sulphide) (PPS) directly from bis(4‐bromophenyl) disulphide (BBD) have been established. Reactions were performed in a boiling quinoline/pyridine solvent mixture (91% by vol. quinoline) in the presence and absence of copper powder. Reaction products were fractionated and the fractions characterised using elemental analysis, IR and NMR spectroscopy, viscometry, hot‐stage microscopy, differential scanning calorimetry, thermogravimetry and curing studies. The yields and properties of the polymeric fractions are compared to those of similar fractions obtained from preparation of PPS by solution polymerisation of copper(I) 4‐bromobenzenethiolate under conditions which correspond to those employed in this work. PPS was not produced, and BBD was almost quantitatively recovered when copper was absent from the reactants. Reactions performed using an equimolar ratio of copper to BBD produced PPS of molar mass approximately 2–4 × 10 3 gmol −1 in 76% yield after 8h reaction. However, this PPS was contaminated with an insoluble infusible material which had a deleterious effect on the physical properties of derived cured PPS materials. The yield of PPS decreased and the quantity of contaminant increased as reaction time increased. PPS of molar mass approximately 10 4 g mol −1 was obtained in 50–60% yield, free from insoluble infusible material, when the molar ratio of copper: BBD was increased to 2:1; it exhibited normal properties on curing.