Characterisation of vinyl chloride oligomers

A low molecular weight fraction was obtained from a mass polymerised PVC resin by using diethyl ether Soxhlet extraction followed by either preparative gel filtration or solvent fractionation. A gas chromatography - mass spectroscopy (GC-MS) analysis of this fraction revealed that, in addition to vinyl chloride (VC) oligomers, it contained a large number of other compounds, in particular a large concentration of phthalates. By using adsorption liquid chromatography it was possible to remove the phthalates, along with other contaminants having a similar or greater polarity, from the low molecular weight PVC fraction. [Continues.]