Modification of bisphenol a dicyanate ester by carboxyl-terminated liquid butadiene-acrylonitrile and its composites

Cyanate esters with excellent high-temperature properties and easy processing are well known as good resin materials used in aerospace and electrical industries, but the drawback of brittleness limits their usage. In this study, carboxyl-terminated liquid butadiene-acrylonitrile (CTBN) was introduced to improve the toughness of bisphenol A dicyanate resin (BADCy), a typical kind of the cyanate esters. Fourier transform infrared spectroscopy and differential scanning calorimetry were employed to investigate the effects of CTBN on the curing behavior of BADCy; the results indicate that the addition of CTBN has a great influence on the curing behavior of BADCy at lower temperatures, but little at higher temperatures. Data from the thermogravimetric analysis and heat deflection temperature analysis showed that the thermal properties of the modified systems were poorer than that of pristine BADCy resin. On the basis of the scanning electron micrographs of the modified systems, toughening mechanism of the systems was discussed. Mechanical and dielectric properties of the cured resins and glass fiber-reinforced composites were also studied. Modified systems exhibit attractive properties for the future applications in aerospace industries.