▎ 摘　　要

NOVELTY - Composition comprises: (a) a polyfunctional cyanate ester; (b) an asymmetric bisphenol-derived cyanate ester; and (c) substituted heterocyclic compounds (I). USE - The composition is useful as matrix in composite materials. ADVANTAGE - The composition exhibits: high glass-transition temperatures and low dielectric constants; good long-term thermal stability at elevated temperatures; good toughness; and good fire, smoke and toxicity performance. DETAILED DESCRIPTION - Composition comprises: (a) a polyfunctional cyanate ester; (b) an asymmetric bisphenol-derived cyanate ester; and (c) substituted heterocyclic compounds of formula (I). Either R3-R6 = H, halo, and groups that provide a thermally stable (I); or R3-R6 = H, halo, and aromatic groups; and R1, R2 = H, halo, and other electron withdrawing groups, where at least one of R1 and R2 are halo. INDEPENDENT CLAIMS are also included for: (1) cured resinous material obtained by or obtainable by curing a composition; (2) composite material comprising a cured resinous material; (3) article comprising a cured resinous material according or a composite material, optionally a gas turbine engine component; and (4) making a composition comprising mixing a polyfunctional cyanate ester, an asymmetric bisphenol-derived cyanate ester, and (I).