2,2'-Bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoro- propane; 2,2-Bis((4-cyanatophenyl) propane; 1,1-Ethylidenebis (phenyl-4-cyanate); 4,4'-Methylene bis(2,6-dimethylphenylcyanate); and 1,3-Phenylenebis (1-methylethylidenebis) cyanic acid, 1,4-phenylene ester