Cyanate ester resins are a family of high-temperature thermosetting resins that bridge the gap in thermal performance between engineering epoxy and high-temperature polyimides. This article discusses the chemistry, properties and characteristics of the cyanate ester resins. It describes the processing procedures for the cyanate ester resins and provides information on properties for selected applications, such as space applications, radomes, and printed circuit boards.

A thermosetting resin, or thermoset, is a synthetic organic polymer that cures to a solid, infusible mass by forming a three-dimensional network of covalent chemical bonds. Significant applications include construction and thermoset engineering plastics. This article discusses the general and family characteristics of thermosetting resin families, including allyls, aminos (urea formaldehyde and melamine formaldehyde), cyanates, epoxies, polybenzimidazoles, unsaturated polyesters, thermoset polyimides, phenolics, and vinyl esters. It also explains processing methods, including curing and curing agents. The article provides descriptions of commercial product forms and the wide array of applications of thermosetting resins. It also tabulates the performance properties (mechanical, thermal, electrical and chemical resistance) of some families of unfilled or unreinforced thermosetting resins and reinforced or filled grades.