Synthesis, characterization and properties of novel dimethyl phenyl bridged flame retardant cyanate ester

Two dimethyl phenyl bridged cyanate ester was prepared. Phenol precursor 1, 4-bis (4-hydroxybenzyl) benzene (BHBZ) and 1, 4-bis (3, 5-dimethyl -4-hydroxyl-benzyl)benzene(BBZ) were obtained by the reaction of phenol and 2, 6-dimethyl phenol with 1, 4-bis(methoxymethyl) benzene respectively. The corresponding CE were prepared through the reaction of precursor with cyanogen chloride. The chemical structures of phenyl precursor and cyanate resin were characterized by FTIR, ESI-MS and 1H-NMR. The thermal properties, dielectric properties, hygroscopic properties and flame retardant, etc of cured resin were studied and compared with BADCy. The cured BHBZCy and BBZCy exhibited yield of 55.2% and 40.5% at 800°C, dielectric constant of 3.03 and 2.81 at 1 MHz, water absorbtion of 0.87% and 1.0% after 80 h. Both cured resin reach V-0 at UL-94 flame test.