New catalysts combined with an organic or inorganic lithium salt (lithium acetate or lithiumchloride) and a conventional catalyst for the transesterification of dimethyl terephthalate withethylene glycol have been stu...New catalysts combined with an organic or inorganic lithium salt (lithium acetate or lithiumchloride) and a conventional catalyst for the transesterification of dimethyl terephthalate withethylene glycol have been studied. Reaction mechanism in presence of lithium-base catalyst hasbeen proposed. A synergistic action of two classes of catalysts creates the speed-up of initial re-action particularly in presence of lithium acetate. The presence of lithium base catalyst can re-duce diethylene glycol content and raise the melting point of final PET product, but almostuneffect PET molecular weight distribution.展开更多
The transesterification of diphenyl carbonate （DPC） with 1,4-butyldiol （BD） was kinetically investigated in the presence of lithium acetate catalyst at 465 K.The reaction was followed by the measurement of the qua...The transesterification of diphenyl carbonate （DPC） with 1,4-butyldiol （BD） was kinetically investigated in the presence of lithium acetate catalyst at 465 K.The reaction was followed by the measurement of the quantity of phenol which was distilled from the reactor.The experiments supported the assumption that the phenyl ester groups in DPC and phenyl hdroxybutyl carbonate （PHBH） had the same reactivity,and the transesterification obeyed first-order kinetics with respect to DPC and BD,and a rate equation was derived.The reaction rate was found to be first order with respect to the catalyst concentration as well.When those data were incorporated in the rate equation,excellent agreement between calculated values and the observed ones was recognized over a wide range.展开更多
以TiO2和醋酸锂为原料,采用在乙醇中预分散和在液相体系中熔融浸渍的协同共混技术,实现反应物料间微尺度混合,在较低温度下分段煅烧合成纳米结构钛酸锂.X射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscope...以TiO2和醋酸锂为原料,采用在乙醇中预分散和在液相体系中熔融浸渍的协同共混技术,实现反应物料间微尺度混合,在较低温度下分段煅烧合成纳米结构钛酸锂.X射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscope,SEM)和粒度分布等测试结果表明,产物为尖晶石结构钛酸锂(Li4Ti5O12),平均粒径约为550 nm.以该产物为负极材料组装锂离子电池并测试其电化学性能,结果表明其性能良好,0.1 C倍率下首次充放电比容量高达165 mA.h/g,具有稳定的电压平台,循环性能良好.展开更多
针对传统锂吸附剂为粉末材料时机械强度和渗透性差等问题,采用乙烯-乙酸乙烯共聚物(EVA)作为黏合剂制备一种新型EVA/HMO复合吸附剂。在EVA质量分数为18%、致孔剂质量分数为5.0%、热熔温度为121℉的条件下制备的粒状吸附剂形态最佳、磨...针对传统锂吸附剂为粉末材料时机械强度和渗透性差等问题,采用乙烯-乙酸乙烯共聚物(EVA)作为黏合剂制备一种新型EVA/HMO复合吸附剂。在EVA质量分数为18%、致孔剂质量分数为5.0%、热熔温度为121℉的条件下制备的粒状吸附剂形态最佳、磨损量低,其吸附容量为26.35 mg/g。对该粒状吸附剂动态吸附过程进行研究,确定卤水用量为250 m L,此时吸附率为85.4%;解洗液用量为90 m L,解吸率为99.1%。此外对粒状吸附剂的循环性能进行研究,经过20次连续实验,锂吸附率在85%左右,解吸率在100%左右,吸附剂的溶损率约1×10^(-3)%,表明该粒状吸附剂提锂效果良好、锰溶损率极低。展开更多
文摘New catalysts combined with an organic or inorganic lithium salt (lithium acetate or lithiumchloride) and a conventional catalyst for the transesterification of dimethyl terephthalate withethylene glycol have been studied. Reaction mechanism in presence of lithium-base catalyst hasbeen proposed. A synergistic action of two classes of catalysts creates the speed-up of initial re-action particularly in presence of lithium acetate. The presence of lithium base catalyst can re-duce diethylene glycol content and raise the melting point of final PET product, but almostuneffect PET molecular weight distribution.
基金supported by the Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period(2006BAE02B03)
文摘The transesterification of diphenyl carbonate （DPC） with 1,4-butyldiol （BD） was kinetically investigated in the presence of lithium acetate catalyst at 465 K.The reaction was followed by the measurement of the quantity of phenol which was distilled from the reactor.The experiments supported the assumption that the phenyl ester groups in DPC and phenyl hdroxybutyl carbonate （PHBH） had the same reactivity,and the transesterification obeyed first-order kinetics with respect to DPC and BD,and a rate equation was derived.The reaction rate was found to be first order with respect to the catalyst concentration as well.When those data were incorporated in the rate equation,excellent agreement between calculated values and the observed ones was recognized over a wide range.
文摘针对传统锂吸附剂为粉末材料时机械强度和渗透性差等问题,采用乙烯-乙酸乙烯共聚物(EVA)作为黏合剂制备一种新型EVA/HMO复合吸附剂。在EVA质量分数为18%、致孔剂质量分数为5.0%、热熔温度为121℉的条件下制备的粒状吸附剂形态最佳、磨损量低,其吸附容量为26.35 mg/g。对该粒状吸附剂动态吸附过程进行研究,确定卤水用量为250 m L,此时吸附率为85.4%;解洗液用量为90 m L,解吸率为99.1%。此外对粒状吸附剂的循环性能进行研究,经过20次连续实验,锂吸附率在85%左右,解吸率在100%左右,吸附剂的溶损率约1×10^(-3)%,表明该粒状吸附剂提锂效果良好、锰溶损率极低。
