A uniform solidified core layer formed by compounding carbon fibers and resins is arranged inside a carbon fiber compound core conductor, while the material has extremely high requirements for a curing speed, glass-transition temperature, toughness and the like of the resins.
At present, common resins belong to an epoxy resin system, while a general epoxy resin system has a defect of low heat resistance. Although partial resins have good heat resistance, the glass-transition temperature Tg of a cured matter is generally not higher than 180° C., interfacial properties are poor, and tensile strength and toughness are poor. Although high heat resistance may be obtained by modifying the general epoxy resin, the general epoxy resin is difficult to be applicable to large-scale production due to limited raw materials and a complicated manufacturing process.
Since the adopted epoxy resin system has great problems in heat-resisting class and raw materials, a new-generation resin with more excellent high-temperature-resistant characteristics and intrinsic toughness than the epoxy resin is needed at present. Then, a cyanate ester resin seizes the opportunity to respond to market demands and inevitably becomes a new development direction.
Although the cyanate ester resin has extremely high heat resistance, toughness of the cyanate ester resin is insufficient due to a limitation of the own structure, and the cyanate ester resin is difficult to be directly applied to a pultrusion process. Then, modification of the cyanate ester resin becomes a necessary trend. In a traditional modification method, an additional toughening agent or resin is adopted for compounding, but such a method may bring influences that the glass-transition temperature is decreased and partial mechanical properties and electrical properties are reduced.