LIQUID PROCESSABLE, THERMALLY STABLE, HYDROPHOBIC, PHENOLIC-TRIAZINE RESINS FOR ADVANCED COMPOSITE APPLICATIONS

摘要

Composite structures are seeing demand for higher temperature performance and thus there is a need for advanced resin systems to meet this requirement. Here a commercial phenolic-triazine (PT) resin is combined with a blend of low viscosity difunctional cyanate ester (Primaset LECy) to achieve a series of reactive binary systems. Throughout this work, the properties of the blends are compared against an industrial standard (Primaset PT-30). The thermomechanical performances of the cured blends compare favourably with the industrial standard system with the best performing systems exhibiting T_g values in excess of 300°C, based on the drop in storage modulus (compared with a value of at least 350°C for PT-30). After conditioning for 3127 hours at 80°C and 85% RH, a cured binary resin blend absorbed 4.9 wt% of moisture, compared with a figure of 5.2 wt% for PT-30. When exposed to 250°C in air continuously over a period of 3048 hours, the best performing of the binary cured blends lose 48.3% of their mass, compared with 45.0% for PT-30 under the same conditions. The importance of this work is that the newly proposed resin blends containing 20 to 25 wt% LECy exhibit low viscosities (<1000 mPa.s) at 50°C and are considerably more suitable for liquid composite moulding processes when compared with the state-of-the-art commercial matrix, while showing improved moisture performance, with only minimal loss in thermal performance.