Poly[oxy(ethylthiomethyl) ethylene] (ETE) was prepared from poly[oxy (chloromethyl) ethylene] (CE) by reaction with sodium ethanethiolate. Sulfoxide and sulfone analogues were synthesized by oxidation of the poly [oxy(ethylthiomethyl) ethylene]. By changing the chloromethyl/sodium ethanethiolate ratio, poly[oxy(chloromethyl) ethylene-co-oxy( ethylthiomethyl) ethylene] (CE-ETEs) were easily made. Poly [oxy(ethylsulfinylmethyl)ethylene] (ESXE), poly [oxy(chloromethyl)ethylene-co-oxy( ethylsulfinylmethyl)ethylene] (CE-ESXEs), poly[oxy(ethylsulfonylmethyl)ethylene] (ESE), and poly[oxy( chloromethyl) ethylene-co-oxy( ethylsulfonylmethyl)ethylene] (CE-ESEs) were obtained by oxidation of ETE or CE-ETEs. There was little if any chain degradation. The (co)polymer structures were confirmed by FTIR and H-1-NMR spectroscopic studies. Their thermal properties were studied by DSC and TGA. T(g)s of ETE, ESXE, and ESE were -57, 36, and 57 degrees C, respectively, and T(d,o)s (initial decomposition temperature, TGA) were 331, 198, and 308 degrees C, respectively.