<p>The present polysilethylenesiloxane is a liquid polymer represented by the following general formula: <CHEM> wherein R<1> and R<2> each represent a lower alkyl group and R<3> and R<4> each represent a perfluoroalkylethyl group, and n is an integer of 10 to 1,000. This polymer is quite useful as a major component of elastomer compositions having chemical resistance, electrical properties, and high strength.</p>
