SOME PHYSICAL-PROPERTIES OF 2 HOMOLOGOUS SERIES OF PERFLUORO-POLYOXYALKYLENE OLIGOMERS

Glass transition temperature T(g), specific volume v and viscosity eta were measured for two homologous series of oligomer fractions having the same linear perfluorinated poly(oxymethylene-co-oxyethylene) molecular body, and a pair of equal end units -CH2OH or -CH2OCOCF3. By decreasing the molecular weight a marked end unit effect is observed in a progressively differing value of every property of the two series. Typical two-parameter equations are valid, to a first approximation, to represent T(g)-M and upsilon-M relations, whereas the diol series shows a remarkably anomalous, non-monotonic trend of the eta-M relation, which does not follow the typical exponential equation below M(c), as does on the contrary the trifluoroacetate series.