polymerization a great portion of the lesser reactive more volatile components will polymerize thereby insuring higher yields an inert environmental gas pressure of 250 psi but not limited to this pressure can be used successfully with a processing temperature of 150 u00b0 c gases ideal for this application are dry nitrogen argon and other gases inert to the reaction dry conditions are necessary when processing cyclic silazanes since these materials are susceptible to moisture attack and oxidation if air is present when processing these materials shrinkage becomes an issue partiuclarly in efforts to process tolerance controlled parts shrinkage results from the loss of mass but this loss also causes an increase in density cracking and a matrix volumetric reduction volumetric reduction begins immediately on curing since there is an evolution of gas such as hydrogen and some alkyl components additionally if sufficiently high molecular weight improvements and crosslinking have not been made there is a tendency for chemical breakdown of components into low molecular weight units to occur processing to higher temperatures than 150 u00b0 c can result in the evolution of the above materials curing to 150 u00b0 c only yields a cured polymer material additional heating to higher temperatures is critical to yield preceramic materials a temperature processing cycle to 700 u00b0 c results in a cured preceramic upon heating to these temperatures a weight loss is experienced due to the evolution of hydrogen methane and other products when processing methylhydridocyclosilazane it is during.