Synthesis of Poly(p-Benzenesulphonamide) Part II Solid State Polymerisation of Aniline-4-Sulphochloride via a Sulphene intermediate
✍ Scribed by Contreras, Jordi ;Jones, J. Idris
- Book ID
- 104527107
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2007
- Tongue
- English
- Weight
- 580 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0007-1641
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✦ Synopsis
Abstract
On heating, aniline‐4‐sulphochloride undergoes a two‐stage solid state polymerisation with initial formation of an intermediate product, identical in composition with that of the starting material, which, at a higher temperature, eliminates hydrogen chloride to yield poly(p‐benzenesulphonamide). The intermediate product has been identified as 4‐imino‐cyclohexadiene sulphene hydrochloride and results from a rearrangement reaction of aniline‐4‐sulphochloride. On treatment with dry pyridine, this intermediate undergoes dehydrochlorination to yield transiently the monomeric sulphene, 4‐imino‐cylcohexadiene sulphene, which then polymerises to poly (p‐benzene sulphonamide). This reaction has been followed spectroscopically in an ultra‐violet cell.
When a sample of aniline‐4‐sulphochloride was heated to 200°C in a sealed tube an acid catalysed rearrangement of the polysulphonamide occurred to give some units of p‐amino‐p‐phenylene sulphone in the polymer chain.
Solid state polymerisation of aniline‐4‐sulphochloride hydrochloride also occurs on heating to 175°C under reduced pressure, with evolution of hydrogen chloride, but without the formation of an intermediate product. Here again, in a closed system, some acid catalysed rearrangemnt of the polymer was observed. N‐Methylaniline‐4‐sulphochloride hydrochloride similarly undergoes a solid state thermal polymerisation with evolution of hydrogen chloride to yield poly (p‐benzene‐N‐methyl‐sulphonamide).
Considerable interest is attached to the discovery of the stable crystalline 4‐imino‐cyclohexadiene sulphene hydrochloride intermediate and the generation therefrom of the parent sulphene which serves as monomer in the polymerisation. The stability and reactivity of sulphenes generally are discussed.