ABSTRACT
Abstract Different diols were prepared by the condensation of 2,6-dimethyl phenol/1-naphthol with different aldehydes, dichlorodiphenylsilane with 1,4-dihydroxy anthraquinone and vanillin with different diamines. All the diols prepared and 1,4-dihydroxy anthraquinone were converted to dicyanate. The synthesized diols and dicyanates were characterized by elemental analysis, FT-IR, 1H-NMR and 13C-NMR. The cure behaviour of all the dicyanate monomers and their blends with epoxy/BMI was studied using DSC. The monomers were then cured into thermoset polymers after heating at 180◦C for 1 h and 220◦C for 1 h. FT-IR, solid state NMR, TGA and DSC were used to characterize the polymers. All the polymers exhibit a common maximum decomposition temperature of 420 ± 5◦C, which is characteristic of the cyanurate ring. However, the percentage char yield is found to depend on the chemical structure. The Tg of the polycyanates depends on the structure of the monomer. The dicyanates were blended with commercial epoxy/DDM system. The Schiff base functionalized cyanate ester was blended with BMI at various proportions. The blends were characterized by FT-IR. Composite laminates were fabricated from E-glass fiber plain-woven fabric and epoxy resin or cyanate/epoxy or BMI blend. The mechanical properties such as tensile, flexural and impact strengths and fracture toughness of the blends and composites were studied as per ASTM standards. The blends and composites were evaluated by SEM analysis and DMA.
