if the novolac resin is a solid the hydroxyarylphosphine oxide novolac resin mixture may be processed as a solid blend and used in the solid form an optional embodiment is the addition of the hydroxylated phosphine oxide and the novolac resin individually into the curable resin formulation unless otherwise indicated or it is clear from the context the terminology phenolic novolac resin and the like means and includes hydroxyl functional resinous compositions including the condensation products of one or more substituted or unsubstituted phenolic compounds and one or more aldehydes preferably formaldehyde such resins may optionally include heteroaryl components such as melamine and guanamines as noted hereinafter in one of the embodiments of this invention r 1 in the above formulae is derived from an alkyl aryl ether examples of such starting materials include methoxyphenyl 4 methoxynaphthyl o methoxycresyl and so forth this invention utilizes a mixed grignard reagent system to produce a mixture of phosphine oxides this invention can be applied to a wide array of compounds wherein an arylmagnesium halide can be mixed with an alkoxyarylmagnesium halide and reacted with phosphorus oxychloride or alternatively an alkylmagnesium halide can be reacted with phosphorus oxychloride in tandem with an alkoxyarylmagnesium halide the generalized approach is to use a main grignard reagent that contains a functional group that can be chemically transformed to a group capable of reacting with a wide variety of active intermediates and furthermore using a second grignard reagent that is functionally inert the relative stoichiometry between the two grignard reagents and the phosphorus oxychloride can be adjusted to affect the distribution of the mixtures in the desired fashion at will the two grignard reagents can be premixed and reacted with the phosphorus oxychloride together or the reagents.