Method of forming high-temperature resistant polymers

A method of forming high-temperature resistant polymers said method comprising the steps of

• (a) curing a polymerisable composition (A) containing at least one compound of the formula VI:
• ##STR24## wherein is a single or multiple aromatic ring structure, each R.sup.a, which may be the same or different, is H or alkenyl, which may optionally be substituted;
• each R.sup.b, which may be the same or different, is alkenyl, which may optionally be substituted,
• each R.sup.c, which may be the same or different, is a polymerisable or non-polymerisable group which does not interfere with the polymerisation of the composition;
• n=1-3;
• m=0-3;
• .ltoreq. (m+n).ltoreq.6;
• 0.ltoreq.s.ltoreq.r-(m+n) where r is the total number of substitutable positions on the ring structure:
• provided that
• (I) when the polymerisable composition A comprises a compound of formula VI and a matrix monomer, said matrix monomer being curable or polymerisable under the curing conditions of step (a), then (i) at least two of the moieties R.sup.a and/or R.sup.b must have unsaturation at the alpha or beta carbon atom or (ii) at least one of the moieties R.sup.a, R.sup.b or R.sup.c is polymerisable or curable under the curing conditions of step (a) and at least one other of R.sup.a or R.sup.b has unsaturation at the alpha or beta carbon atoms;
• and
• (II) when the polymerisable composition A comprises a mixture of compounds of formula VI then (i) at least one of said compounds has at least one moiety R.sup.a, R.sup.b or R.sup.c which is polymerisable or curable under the curing conditions of step (a) and at least one moiety R.sup.a or R.sup.b which has unsaturation at the alpha or beta carbon atom and (ii) the other compound has the same requirements as I (i) or II (i) above;
• and
• (III) when the polymerisable composition A contains as the only polymerisable component, a compound of formula VI, then said compound has at least one moiety R.sup.a, R.sup.b and/or R.sup.c which is polymerisable or curable under the curing conditions of step (a) and at least one moiety R.sup.a and R.sup.b which has unsaturation at the alpha or beta carbon atom;
• and
• provided that the curing conditions for step (a) are not such as would cause the substantial polymerisation of the moieties R.sup.a and R.sup.b having alpha or beta unsaturation, and
• provided that when m.dbd.0 or when the required number of moieties R.sup.a and R.sup.b having alpha or beta unsaturation is greater than the number of R.sup.b moieties having said alpha or beta unsaturation, then at least one position ortho to each --OR.sup.a (R.sup.a not equal to H) or the para position thereto, or in the case of a fused ring structure at least one substitutable position on the fused ring, is unsubstituted;
• the alpha carbon atom being that carbon atom nearest the oxygen atom (in the case of R.sup.a) or the ring (in the case of R.sup.b);
• and
• (b) subsequently heating the cured composition in the presence of acid to form a high temperature resistant crosslinked resin.