Poly Thiocarbonyl Fluoride and Related Elastomers

Poly(thiocarbonyl fluoride) and related fluorothiocarbonyl compounds have been the subject of extensive study in recent years and at least two reviews (Sharkey, 1969 1972) have been devoted to these materials. Commercial production of the material in the near future, however, seems unlikely. 

Thiocarbonyl fluoride, (Cp2=S), (b.pt-54 C) has been prepared by a number of methods and that apparently preferred for laboratory preparation involves dimerization of phosgene, fluorination of the dimer and subsequent pyrolysis. 

A direct method giving high yields of monomer involves reaction of sulphur with chlorodifluoromethane. 

Polymerization may be brought about both by anionic and free radical methods. Typical anionic polymerizations are carried out at -78°C in anhydrous diethyl ether with dimethyl formamide as initiator. Number average molecular weights for the polymer are typically in the range 300000-400000. Free radical polymerization is carried out effectively using triethyl borane/oxygen as the initiator. Similar temperatures to those used in anionic polymerization are preferred. 

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W. H. Sharkey, Poly(thiocarbonyl fluoride) and related elastomers, in Polymer Chemistry oj Synthetic Elastomers, Pt. II (J. P. Kennedy and E. G. M. Tornqvist, eds.). Interscience, New York, 1969. 

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