Hyunjun, Y; Cho, J; Kwon, Y; Hun, JS; Chung, M; Ahn, HG; 곽원봉
Styrenated phenols(SPs) are an important raw material of a surfactant for preparing a developing solution of LCD panel. Homogeneous catalyst is mainly used in the SPs synthesis, but the unreacted phenol that can adversely affect the human body is contained in the SPs. In this study, SPs involving very small amount of unreacted phenol and high content of di-styreated phenol(DSP) were synthesized, which can be used to prepare styrenated phenol alkoxylate. The solid SO42-/ZrO2 catalyst was prepared by impregnation method with using Zr(OH)4. SO42- on the catalyst was introduced from an aqueous 1M-H2SO4 solution. The catalysts were characterized by XRD patterns and FT-IR spectra. The catalytic activity was examined by measuring conversion of phenol and styrene in a batch liquid-phase reactor. From XRD patterns, it was confirmed that the crystalline of ZrO2 with a mixture of monoclinic and tetragonal phases was formed by the sulfation of Zr(OH)4 with sulfuric acid solution. FT-IR spectra showed the presence of 1,075 cm-1 and 1,202 cm-1 peaks due to the asymmetric vibration of O-S-O bonds. In synthesis reaction of SPs, selectivity of mono- styrenated phenol(MSP) was decreased while selectivity of tri-styrenated phenol(TSP) was increased with increasing concentration of sulfuric acid solution. Selectivity of DSP was decreased when amount of catalyst was increased. With increasing reaction temperature, selectivity of MSP was decreased, and the selectivity of DSP and TSP was kept to be constant from at reaction temperature of 80℃ and 100℃, respectively. As the results, the optimum synthesis conditions for concentration of sulfuric acid solution, catalyst amount of reactants, reaction temperature over SO42-/ZrO2 catalyst, and reaction time were 5 wt%, 3 wt%, 80℃, and 6 hr, respectively. At these conditions conversion of both phenol and styrene were almost 100%, and the selectivity of MSP, DSP, and TSP was 18.3%, 63.5%, and 18.1%, respectively.