Synthesis And Application Of Bisphenol Active Esters

Active ester refers to the aromatic ester compounds containing two or more ester groups with higher activity in one molecule,which can react with epoxy resin.Compared with the traditional polyamine curing agents,the active esters do not produce strongly polar hydroxyl groups after the reaction of the active esters with the epoxy resin under the action of promoters,and thus do not lead to the deterioration of the dielectric constant?D_k?and dielectric loss?D_f?of the prepared materials.The synthesis conditions of Bisphenol-type active esters were studied.The structure and thermal properties of the active esters were characterized.The curing process and kinetics of the epoxy resin composite of active ester and dicyclopentadiene?DCPD epoxy resin?were discussed.The application of active ester/DCPD epoxy resin composite was discussed.The main contents are as follows:1.The main influencing factors of Bisphenol A type of active ester synthesis optimization,select optimum condition for synthesis of active ester is:in 20?under constant temperature,nitrogen protection,dissolved the Bisphenol A in pyridine;TPC and IPC were weighed according to the ratio of substance amount to 1:1.The sample was dissolved with DCM,and the reaction system was dripped in the same time.After reaction for 4 h,the end sealant was added according to the molar ratio,and after reaction for 5 h,the reaction was completed.Pour organic phase into deionized water,adjust pH to 5 with formic acid,and wash for 4 times.The organic phase is separated at rest.Atmospheric evapotranspiration DCM.The precipitated resin was washed with ethanol for extraction.Under the condition of100?drying 6 h.The white bisphenol-type active ester was obtained.2.According to the infrared spectrum analysis,the stretching vibration peak of hydroxyl at3460 cm^-1 of the active ester of end sealing agent including phenol,para-cresol and?-naphthol disappears,indicating that the synthesis process can achieve the end sealing effect.According to the HNMR analysis,the three active esters reacted according to the actual feed ratio to achieve the synthesis purpose.DSC test showed that none of the three active esters had crystallization absorption peaks.TG test showed that the carbon residues of the three active esters were all around 28.0%,with good thermal stability.3.The curing process of three Bisphenol-type active ester/DCPD epoxy resin composites was preliminarily studied by non-isothermal DSC method.From the parameters obtained,the apparent activation energy,reaction order,preexponential factor and so on were calculated through the Kissinger,Ozawa and Crane formulae,and the curing kinetic equation of the reaction was obtained,providing theoretical basis for the further preliminary application.4.Resin tablets and layer samples were prepared from three kinds of Bisphenol-type active ester/DCPD epoxy resin composites D_k,D_f and thermal stability of resin sheet and laminate were tested.The results show that the dielectric properties of resin sheet are better than laminates.Both in the 600?carbon residue rate is over 28.5%,good thermal stability.5.Considering the practical application,the laminates were prepared with polyamine curing agent.The D_k and D_f of the samples were 3.42 and 0.0203,respectively.In addition,the surface resistivity,volume resistivity,breakdown voltage,bending strength and impact strength of the active ester laminate were tested,and the results showed that the electrical and mechanical properties of the active ester laminate were good.