Synthesis Of Diphenolic Acid And Biomass-based Polycarbonate

Diphenolic acid was a key raw material for the synthesis of biomass-based polycarbonate material,but the disadvantages of the catalysts used are obvious.This paper prepared a novel solid acid catalyst with nutshell as the raw material and used for the preparation of DPA by optimizing reaction conditions.The product Diphenolic acid was further used in the synthesis of diphenol acid based polycarbonate.First,the carbonized sulfonic acid based on bio-mass nutshell was prepared with nutshell and toluene-p-sulfonic acid as raw materials by an one-step hydrothermal carbonization and sulfonation process.The catalyst was characterized by SEM,FT-IR,NH3-TPD and thermo-gravimetric analysis.The results show that the bio-mass carbon sulfonic acid produced have the larger pores,the initial decomposition temperature of 260 oC and acid amount of 0.946mmol/g.Then,this bio-mass carbon sulfonic acid was used in the catalytic synthesis of DPA.The effects of reaction temperature,reaction time,the ratio of raw materials,and catalyst dosage on the DPA yield was tested,and the DPA yeild was 92.0% under optimum conditions: catalyst dosage was 10%wt(LA),the molar ratio of phenol to LA was 4:1,reaction temperature was 120℃,and the reaction time was 24 h.The prepared DPA as a substitute of BPA was successfully used to prepare a biomass-based polycarbonate by melt transesterification.The effects of the initial ratio of raw materials,catalyst dosage,temperature and time on the molecular weight of product was investigated,optimum conditions was obtained as follows: the initial ratio of raw materials n(DPC):n(DPA)is 1.04:1,the catalyst dosage of tetraethyl ammonium hydroxide is 2%wt(DPA),the end temperature of polycondensation is 210℃and the time is 12 h,at this condition,the molecular weight of the product is 20000,Finally,the structure of PC was analyzed by FI-IR and the mechanical properties were measured.