Phenylene sulfide polymers. I. Mechanism of the macallum polymerization

Abstract

The reactions used in the past for the preparation of phenylene sulfide and related polymers are reviewed. The Macallum polymerization is a polycondensation of an aryl halide and an inorganic sulfide or polysulfide in the absence of solvents. The monomer system studied most thoroughly is represented by the following, unbalanced equation:

Polymers and Sulfur: what are Organic Polysulfides Good For? Preparative Strategies and Biological Applications

“…Almost a decade later, Lenz and co‐workers at the Dow Chemical Company in Michigan systematically expanded Macallum's synthetic approach, proposing a plausible mechanism of this polymerization:50 initially, via a free‐radical mechanism, sulfur attacks the aryl halide, forming a polysulfide side chain. The polysulfide side chain is then cleaved by nucleophilic substitution to give the corresponding thiophenoxide anion, which subsequently initiates the polymerisation by forming the first diaryl sulfide linkage, thanks to it being a much stronger nucleophile than the sulfide or polysulfide anions.…”

“…The polysulfide side chain is then cleaved by nucleophilic substitution to give the corresponding thiophenoxide anion, which subsequently initiates the polymerisation by forming the first diaryl sulfide linkage, thanks to it being a much stronger nucleophile than the sulfide or polysulfide anions. Successive nucleophilic substitution reactions by sulfide and thiophenoxide anions on the haloaryl sulfides result in chain extension 50. The same research group then examined in great detail the structure of the obtained linear and branched (co)polymers51 (Example G in Table 1) and optimised synthetic procedures, which were suitable for scale‐up, for the linear derivatives 52…”

Glassy poly(p-phenylene sulphide): determination of the local structure

“…Over the next half-century, a number of synthetic routes were described, which probably all produced highly branched and crosslinked polymers. In 1948, Macallum [2] described a synthesis which was further developed by Lenz and co-workers [3][4][5]; the latter also developed a more reproducible preparative procedure. A commercially successful process was developed in 1967 by Edmonds and Hill [6]; poly(pphenylene sulphide) of modest molecular weight has been produced by this process since 1973 by the Phillips Petroleum Company, under the trademark 'Ryton'.…”

Overall Investigation of Poly (Phenylene Sulfide) from Synthesis and Process to Applications—A Review

“…The detailed mechanism of the Macallum polymerization reaction was proposed by Lenz and other coworkers . They proposed several steps concerning this mechanism as follows:…”