POLYSILAZANE COMPOSITION CROSSLINKABLE IN PRESENCE OF METAL OR METAL COMPOUND ACTING CATALYTIC ACTION ON HYDROXYL REACTION

摘要

A crosslinkable composition comprising at least one polysilazane containing at least 2, preferably at least 3, 3BOND SiH groups per molecule and at least 2 SiR2 groups per molecule, R2 being an unsaturated hydrocarbon radical and a catalytically effective quantity of a metal element or of a metal compound to catalyze the hydrosilylation reaction SiH/SiR2. The compositions according to the invention can crosslink under the effect of heat and can be used for coating or impregnating substrates with ceramic material after pyrolysis. The mechanical properties of the crosslinked compositions are assessed by evaluating the relative rigidity RR measured by the fiber torsion pendulum method (FIG. 1).