Synthesis Of Asymmetric Bisphenols And Performance Of Cyanate Ester Resin

Cyanate ester resins are widely applied as advanced composite matrices in the aerospace, electronics and adhesive industries due to their excellent comprehensive properties and electrical insulation in the past few years. With the development of application, they have received considerable attention on improving toughness and process technology. Two novel bisphenols were synthesized and the curing behavior and properties of a new liquid cyanate ester resin were introduced. The main contens were listed as follows:1. Two asymmetric bisphenol products were researched in this paper. 2,2-bis(4-hydroxyphenyl)butane(bisphenol B) was synthesized by phenol and butanone in the presence of heteropoly acid as catalyst,while 1,1-bis(4-hydroxyphenyl)butane(bisphenol BD) was synthesized by phenol and butyraldehyde.Their strutures were determined by FTIR,1H-NMR and HPLC. We chose sulfate, hydrochloride and heteropoly acid as catalyst in synthesis reaction of bisphenol BD.The result showed that heteropoly acid had the best catalytic effective by comparing. We made use of orthogonal experiment which discussed the effects of the reaction factors with heteropoly acid catalyst through HPLC, such as temperature, the mole ratio of phenol and butyraldehyde, the amount of major catalysts and auxiliary catalysts and so on. The yield of product is up to 62.5% under optimal reaction conditions. The reaction dynatics of bisphenol BD was researched, and rate constant was obtained.The results showed that the reaction is best described by a second-order reaction model.2. Bisphenol B cyanate ester resin was characterized. Gel time, DSC and FTIR were used to investigate in curing process of BPACN and BPBCN, respectively. The results showed that dibutyl tin dilaurate had the best catalytic performance for BPBCN curing. The curing kinetics of neat BPBCN and BPBCN in presence of dibutyl tin dilaurate as catalysts were carried out by DSC technique. Curing mechanism and dynamic equation were obtained.We used FTIR follow the curing process of BPACN and BPBCN for theory explaination.3. Thermal property, mechanics strength, chemical resistance and dielectric property were compared between BPACN and BPBCN.The results showed that BPBCN has better thermal performance than BPACN and similar mechanics strength.The two cyanate ester resins had excellent chemical resistance and dielectric properties.