Sulphur Compounds, Stability

These materials, the polymeric sulphones, also come into the category of hexavalent sulphur compounds and are derivatives of sulphonic acids. The photochemistry and the radiation chemistry of these substances have been reviewed in a variety of texts. Thus the radiation chemistry was reviewed in considerable detail in 1988147. Other texts have reviewed photodegradation and photooxidation of polymers in general with some reference to the polysulphones149. It appears that polysulphones have low thermal stability and as a result have failed to undergo commercial utilization149. 

In refining the oil it is necessary to stabilize the crude by removing the liquefied petroleum gases (LPG), generally containing substantial amounts of H2S and other sulphurized compounds that must be eliminated to protect the LPG plant and produce propane and butane suitable for sale. A Reid vapour-pressure analyser monitors whether the crude has been properly stabilized. 

Organotin sulphur compounds are fairly robust compounds, but undergo fission by halogens and halides. They are now manufactured on a large scale for industrial uses, especially as stabilizers for polyvinyl chloride and related plastics, where the R2Sn(SR )2 types are extensively used. ... 

It has been shown in the preceding section that hydroperoxides are involved in the oxidative degradation of poly(vinyl chloride). Many sulphur compounds are known to decompose hydroperoxides into non-radical products and it is likely that organotin mercaptide stabilizers can also react in this way. For example, dimethyltin bis(isooctylthioglycolate) decomposes the model compound, tert-butyl hydroperoxide as follows [14] ... 

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