Studies on the Synthesis and Technology of Dipentaerythritol and Its Derivative
|Keywords||dipentaerythritol synthesis derivative wastewater treatment TiO2|
Dipentaerythritol （DPE） is an important fine chemical intermediate, which has a great significance both in the laboratory and industrial production. Synthesis of DPE and its derivative, together with the technology for the disposal of its wastewater, are studied in this paper.The synthesis of pentaerythritol （PE） and DPE were studied systematically, using formaldehyde, aldehyde and NaOH as the starting material. The influence of the molar ratio of the reactants, final reaction temperature, and dosage of PE were optimized. The conversion of aldehyde is nearly 100.0% and the selectivity of PE and DPE are 91.2% and 4.7%, respectively, while the final reaction temperature is 46℃, the molar ratio is n（formaldehyde）: n（aldehyde）: n（NaOH） = 6.0:1:1.2, and the dosage of PE is 6 wt%.The synthesis of dipentaerythritol hexaacrylate was also studied, using DPE, crylic acid as the starting material. The influence of dosage of inhibitor and acid catalyst were optimized. The yield of dipentaerythritol hexaacrylate is 90.6%, while the molar ratio is n（crylic acid）: n（DPE） = 7.5:1, the dosage of hydroquinone and 4-methylbenzenesulfonic acid is 3 wt% and 4 wt%, respectively.In addition, a process for the photodegradation of PE （DPE） wastewater catalyzed by nano TiO2 is established. A series of TiO2 catalysts were prepared and tested. TiO2-HY was found to have good activity and stability. The TiO2-HY catalyst is proved to be rutile phase with a particle size of 22.6 nm based on XRD, SEM and XPS characterizations. The degradation efficiency is 90.5% in solar light under the optimal operating conditions catalyzed by the TiO2-HY, while the pH value is 6, the amount of catalyst is 0.06 g and the time is 16 hours.