A curable material comprising a blend of a fluorine-containing cyanate and a fluorine-containing poly(arylene ether) wherein said cyanate is a monomer having the structureN.ident.C--O--R--.sub.n --O--C.ident.Nsaid fluorine containing poly(arylene ether) has the structureX--R--.sub.m --Xwherein X is any group capable of reacting with a --C.ident.N group;R is an aliphatic or aromatic group which may or may not be fluorosubstituted;R.sup.1 is an aliphatic or aromatic group which may or may not be fluoro substituted or R.sup.1 is selected from the group consisting of ether, carbonyl, sulfone, phosphine oxide and sulfide, and at least one of R or R.sup.1 must be fluoro substituted;n is 0-10; andm is 0-100;said material being heat-curable at a temperatures between 180.degree. and 325.degree. C.;said material in the cured state comprising a fluorine-containing polycyanurate network having a plurality of discrete phases of said fluorine-containing thermoplastic polymer dispersed therein wherein said thermoplastic polymer phases are of submicron size.