Synthesis, structure, and properties of aromatic polysulfides

Abstract

Polycondensation of haloaromatics and sodium sulfide has been studied. An increase in reactivity of functional groups, a change of the composition of the elementary polymeric unit with a change of the relative amounts of the monomers, and a key role of side‐reactions, i.e. intra(molecular) and macrocyclisation, have been revealed. Low‐melting isomeric poly(phenylene sulfides), as well as their derivatives, reactive telechelic oligomers, have been prepared. New methods of preparation of poly(arene sulfides) by transarylation of diphenyl sulfide, polymerisation of cyclic aromatic sulfides, or by direct polycondensation of arenes with sulfur under the action of AlCl3, as well as by polycondensation of aniline with sulfur in the absence of catalysts have been suggested. Structures and properties of newly prepared polymers have been studied.

Mechanism of poly(p-phenylene sulfide) growth from p-dichlorobenzene and sodium sulfide

“…Figure9. DCB conversion during polymerization in the presence ( ) and absence (O) of 0.20 mol of tetracyanoethylene.…”

Poly(p-phenylene sulfide) Synthesis: A Step-Growth Polymerization with Unequal Step Reactivity

“…The anomalous features of the industrially important − Edmonds and Hill synthesis of poly( p -phenylene sulfide) (PPS) from p -dichlorobenzene (DCB) and sodium sulfide in N -methylpyrrolidinone (NMP) have evoked a variety of mechanistic interpretations in recent years. ,− Although growth of the polymer may be written as a series of conventional condensation steps, the system displays significant deviations from classic , A−A + B−B step-growth polycondensation behavior. First, at incomplete conversions, polymer (or oligomer) yields and molecular weights are higher than expected. ,,− , This feature of PPS synthesis has been demonstrated in several published experimental plots of polymer molecular weight vs extent of reaction (or conversion). ,,, Second, perfect 1:1 stoichiometric monomer ratios are not required to achieve high molecular weight polymer.…”

“…Variations in aryl chloride reactivities in reactions proceeding by an S N Ar mechanism are well-known to be dependent upon the other ring substituents . In fact, for PPS, predictions that rate constants for growth steps might be significantly higher than those for initiation have appeared. ,,,

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“…The anomalous features of the industrially important [1][2][3] Edmonds and Hill 4 synthesis of poly(pphenylene sulfide) (PPS) from p-dichlorobenzene (DCB) and sodium sulfide in N-methylpyrrolidinone (NMP) have evoked a variety of mechanistic interpretations in recent years. 3,[5][6][7][8][9][10][11][12][13][14][15][16] Although growth of the polymer may be written as a series of conventional condensation steps, the system displays significant deviations from classic 17,18 A-A + B-B step-growth polycondensation behavior. First, at incomplete conversions, polymer (or oligomer) yields and molecular weights are higher than expected.…”

“…20 In fact, for PPS, predictions that rate constants for growth steps might be significantly higher than those for initiation have appeared. 12,14,15,21 Three significantly different mathematical models for the PPS polymerization process have been published, but the models either incorrectly assumed heterogeneous reactions between DCB and Na 2 S or failed to fully incorporate an empirically determined set of rate constants for all the key growth, cyclization, and side reactions. 14,21,22 This report presents results that more completely define the kinetics of the commercially practiced PPS polymerization process.…”