| 摘要 |
The invention relates to a method of forming siloxane polymers using a heteropoly catalyst having a Keggin structure. The method comprises contacting a fluid comprising at least one siloxane polymer precursor selected from the group consisting of cyclic siloxanes (I) having the formula (RR'SiO)a and linear siloxanes (II) having the formula <IMAGE> where R is a substituted or unsubstituted monovalent hydrocarbon having from 1 to 6 carbon atoms, R' is hydrogen or a substituted or unsubstituted monovalent hydrocarbon having from 1 to 6 carbon atoms, a is at least 3 and b is at least 1; with an effective amount of a heteropoly catalyst having a Keggin structure, selected from the group consisting of heteropoly acids (III) having the formula HnXM12O40, salts thereof and mixed acid-salts thereof, where X is B+3, Si+4, Ge +4, p+5, M is Mo+6 and n is 3, 4 or 5, as required for the valence of the heteropoly acid to equal 0, at a temperature ranging from about 23 DEG C. to the boiling point of the siloxane polymer precursor.
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