Lanthanum methanesulfonate is synthesized and is used as the catalyst in the esterification of citric acid with 2-ethylhexanol.The effects of reaction temperature,amount of catalyst and alcohol ∕ acid molar ratio hav...Lanthanum methanesulfonate is synthesized and is used as the catalyst in the esterification of citric acid with 2-ethylhexanol.The effects of reaction temperature,amount of catalyst and alcohol ∕ acid molar ratio have been investigated.The products are analyzed by means of FT-IR.The yield can be over 97.5% under the optimum conditions that molar ratio of 2-ethylhexanol to citric acid is 3.60∶1,amount of catalyst is 0.25 %(molar percentage of citric acid),reaction temperature is 120℃～130℃ and operation in vacuum.The catalyst can be reused by simple phase-separation after reaction.It is used repeatedly for 5 times without obvious loss of activity and with the yield still over 90.0%.展开更多
以柠檬酸和2-乙基己醇为原料,用结晶硫酸高铈为催化剂合成环保增塑剂柠檬酸三（2-乙基）己酯,考察了反应温度、催化剂用量、醇酸摩尔比、反应时间等因素对反应结果的影响,对合成的产品进行了红外光谱分析。实验结果表明,硫酸高铈催化合...以柠檬酸和2-乙基己醇为原料,用结晶硫酸高铈为催化剂合成环保增塑剂柠檬酸三（2-乙基）己酯,考察了反应温度、催化剂用量、醇酸摩尔比、反应时间等因素对反应结果的影响,对合成的产品进行了红外光谱分析。实验结果表明,硫酸高铈催化合成柠檬酸三（2-乙基）己酯的最佳反应条件为n（2-乙基已醇）∶n（柠檬酸）=3.60∶1,催化剂用量为柠檬酸质量的1.5%,反应时间为90 m in,反应温度为150℃～160℃,在最佳反应条件下,柠檬酸三（2-乙基）己酯收率在98%以上。展开更多
目的采用气相色谱-三重四极杆串联质谱法(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)测定三峡库区调味油脂产品中的邻苯二甲酸二正丁酯(dibutyl phthalate,DBP)、邻苯二甲酸二(2-乙基)己酯[bis(2-ethylh...目的采用气相色谱-三重四极杆串联质谱法(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)测定三峡库区调味油脂产品中的邻苯二甲酸二正丁酯(dibutyl phthalate,DBP)、邻苯二甲酸二(2-乙基)己酯[bis(2-ethylhexyl)phthalate,DEHP]2种塑化剂的含量,并对污染情况进行分析。方法样品采用乙腈提取,固相萃取(solid-phase extraction,SPE)玻璃小柱净化,氮吹近干后正己烷复溶,经气相色谱-三重四极杆串联质谱法测定。结果DBP、DEHP在一定浓度范围内线性关系良好,相关系数均大于0.998,检出限分别为0.05、0.10 mg/kg,定量限分别为0.17、0.33 mg/kg,平均加标回收率为82.79%~96.70%,相对标准偏差为0.59%~1.76%。在采集的32组调味油脂样品中,DBP的检出率高达68.75%,含量范围在0.15~517.00 mg/kg;DEHP检出率为28.12%,含量范围在0.57~125.00 mg/kg,超标率分别为62.50%和-18.75%。结论三峡库区调味油脂产品中存在一定程度的邻苯二甲酸酯类物质污染,可能与生产、环境等方面的迁移污染相关,需引起重视并进行连续监测。展开更多
文摘Lanthanum methanesulfonate is synthesized and is used as the catalyst in the esterification of citric acid with 2-ethylhexanol.The effects of reaction temperature,amount of catalyst and alcohol ∕ acid molar ratio have been investigated.The products are analyzed by means of FT-IR.The yield can be over 97.5% under the optimum conditions that molar ratio of 2-ethylhexanol to citric acid is 3.60∶1,amount of catalyst is 0.25 %(molar percentage of citric acid),reaction temperature is 120℃～130℃ and operation in vacuum.The catalyst can be reused by simple phase-separation after reaction.It is used repeatedly for 5 times without obvious loss of activity and with the yield still over 90.0%.
文摘以柠檬酸和2-乙基己醇为原料,用结晶硫酸高铈为催化剂合成环保增塑剂柠檬酸三（2-乙基）己酯,考察了反应温度、催化剂用量、醇酸摩尔比、反应时间等因素对反应结果的影响,对合成的产品进行了红外光谱分析。实验结果表明,硫酸高铈催化合成柠檬酸三（2-乙基）己酯的最佳反应条件为n（2-乙基已醇）∶n（柠檬酸）=3.60∶1,催化剂用量为柠檬酸质量的1.5%,反应时间为90 m in,反应温度为150℃～160℃,在最佳反应条件下,柠檬酸三（2-乙基）己酯收率在98%以上。
