Process for polymerizing polyfluoroalkylsiloxane cyclic trimer

A method for making polyfluoroalkylsiloxane fluid consisting essentially of,

• (i) effecting the ring opening polymerization of cyclic polydiorganosiloxane in the presence of a mixture comprising by weight, 0.02 to 0.1 part of water, and an effective amount of a strong acid catalyst having a pK.sub.a of at least 4.7, per 100 parts of polymerization mixture, where the cyclic polydiorganosiloxane consists essentially of a member selected from the group consisting of R(R.sup.1)SiO.sub.1 units, and a mixture of R(R.sup.1)SiO.sub.1 units and (R.sup.1).sub.2 SiO.sub.1 units, where R is a C.sub.(3-8) polyfluoroalkyl radical, and R.sup.1 is a fluorine free C.sub.(1-13) organo radical,
• (ii) treating the resulting mixture of (i) with a neutralizing agent selected from the group consisting of alkaline earth carbonates, alkaline earth oxides, and alkalimetalbicarbonates, and
• (iii) recovering a polyfluoroalkylsiloxane fluid from the mixture of (ii).