Peroxide-substituted polysilazanes
OwnerJoanne M. Schwarkinventor
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Abstract
An uncrosslinked polysilazane containing chemically bound peroxide groups is prepared by reacting a polysilazane and a hydroperoxide at a temperature below the decomposition temperature of the hydroperoxide. A thermoset polymer is formed by heating an uncrosslinked, peroxide-substituted silazane that is also substituted by alkenyl or alkynyl groups at temperatures sufficiently high to decompose the chemically bound peroxide groups to yield a free radical, thereby initiating crosslinking. The crosslinked polysilazanes can be pyrolyzed to form ceramic articles.
Claims21
An uncrosslinked polysilazane comprising silyl peroxide groups having the formula .tbd.SiOOR wherein R is selected from the group consisting of H, substituted or unsubstituted 1-10 carbon alkyl, 2-10 carbon alkenyl, 2-10 carbon alkynyl, aryl, a carboxylic acid and a silyl group.
A process for preparing a crosslinked polysilazane comprising heating an uncrosslinked polysilazane comprising silyl peroxide groups .tbd.SiOOR and .tbd.SiR.sup.3 groups, wherein R is selected from the group consisting of H, substituted or unsubstituted 1-10 carbon alkyl, 2-10 carbon alkenyl, 2-10 carbon alkynyl, aryl, a carboxylic acid and a silyl group, and R.sup.3 is a 2-10 carbon alkenyl or alkynyl group to a temperature sufficient to initiate decomposition of the--SiOOR groups of the polysilazane and further initiate crosslinking through the .tbd.SiR.sup.3 groups of the polysilazane.
Dependencies are inferred from the claim text.