Mesogenic polycyanates and thermosets thereof

A polymerizable composition comprising a mixture of

• (A) at least one thermosettable polycyanate or polycyanamide containing one or more rodlike mesogenic moieties;
• and
• (B) at least one component selected from the group consisting of
• (1) at least one polycyanate or polycyanamide which does not contain rodlike mesogenic structures;
• (2) at least one epoxy resin;
• (3) at least one polymaleimide;
• (4) at least one polyamine;
• (5) at least one polyphenol;
• (6) at least one compound containing one or more polymerizable ethylenically unsaturated group(s);
• (7) at least one compound which contains in the same molecule both a cyanate or cyanamide group and a polymerizable ethylenically unsaturated group;
• (8) at least one compound which contains in the same molecule both a 1,2epoxide group and a polymerizable ethylenically unsaturated group;
• (9) at least one compound which contains in the same molecule both a maleimide group and a cyanate group;
• (10) at least one compound which contains one or more rodlike mesogenic moieties and only one cyanate or cyanamide group per molecule;
• (11) at least one prepolymer of any of the aforesaid components (1) through (10) or any combination of any two or more of said components;
• and
• (12) a mixture of any two or more of components (1) through (11) in any proportion and any combination;
• with the proviso that:
• (i) component (A) may include 4,4'-dicyanatostilbene if components (B-4) or (B-5) are not used;
• (ii) component (A) may include 4,4'-dicyanamidozaobenzene, 4,4'-dicyanamidobenzanilide or 4,4'-dicyanamidophenylbenzoate if components (B-3) or (B-4)are not used;
• (iii) component (A) may include the compositions of Formula IV ##STR34## where R is --H or --CH.sub.3, n=1, Y=--O--C.tbd.N, each A" is independently an alkylene group having from 1 to about 10 carbon atoms, a direct bond, --O--, --CO--, --S--, --S--S--, --SO--, --SO.sub.2 -- or --O--CO--O--;
• each A.sup.1 is independently a --CO--, --O--CO--, --CO--O--, --CO--NR.sup.1 --, or --NR.sub.1 --CO-- group, where both A groups may simultaneously be --O--CO--;
• (iv) component (A) can include the 1,4-bis(p-cyanatophenyl)bicyclo[2.2.2]-octanes represented by the following Formula I ##STR35## where R=--H, a hydrocarbyl or hydrocarbyloxy group having from 1 to about 10 carbon atoms, a halogen atom, a nitro group, a nitrile group, a phenyl group or a --CO--R.sup.1 group where R.sup.1 is hydrogen or a hydrocarbyl group having 1 to about 3 carbon atoms;
• Y=--O--C.tbd.N;
• ##STR36## where n=0, v=2 and R.sup.1 =--H if component (B-1) is not used;
• and (v) component (A) can include the 1,4-bis(p-cyanotophenyl)bicyclo[2.2.2]oct-2-enes represented by the following Formula I ##STR37## where R=--H, a hydrocarbyl or hydrocarbyloxy group having from 1 to about 10 carbon atoms, a halogen atom, a nitro group, a nitrile group, a phenyl group or a --CO--R.sup.1 where R.sup.1 is hydrogen or a hydrocarbyl group having 1 to about 3 carbon atoms;
• Y=--O--C.tbd.N;
• ##STR38## where n=0, v=2 and R.sup.1 =--H if component (B-1) is not used.