Preceramic polymers such as poly(siloxanes) contaimng activefillers can be transformed to ceramic microcomposites withoutsdrinkage during pyrolysis. Volume invariant polymer-cera- micconversion is attributed to the chemical reaction of the activefiller (e.g. carbode, nitride or oxide fonning metals, intermetallicsand cerainic compounds) with solid or gaseous decompo- sitionproducts of the preceramic polymer phase. The microstructures of thisnovel class of polymer derived oxycarbide ceramics are characterizedby network structures of the filler reaction phase, of carbon in theSi-O-C matrix phase and of, residual porosity.
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