阴离子聚合法合成全氟聚醚及其应用研究
发布时间：2018-11-14 10:15
【摘要】：全氟聚醚具有化学惰性、不燃性、低表面张力等特点而被广泛应用于特种化合物改性和高端润滑油领域,但目前国内全氟聚醚产品几乎全部依赖进口。本文以六氟环氧丙烷(HFPO)为原料,开发了阴离子聚合法合成全氟聚醚工艺,并制备出高性能真空泵油。首先考察了不同净化剂组合的净化效果及吸附容量,无水氯化钙-3A分子筛-氧化钙-活性氧化铝组合可以将原料HFPO中的HF、水、六氟丙酮含量分别降低至500 μg/g、2μg/g、300 μg/g,满足聚合反应的要求。论文分析了六氟环氧丙烷阴离子聚合反应的反应机理,表明链增长过程为反应速率的控制步骤,链转移和链再生过程决定了全氟聚醚的聚合度,反应过程中维持低单体浓度有利于获得高平均分子量的聚合产物。从反应工程角度考察了单次进料反应器、分批进料反应器和连续反应器对聚合反应过程的影响。在连续反应器中,单体浓度低、休眠体浓度高、活性体浓度低,有利于聚合反应向高聚合度方向进行。优化的聚合反应工艺条件为:在连续反应器中,以CsF/DG为催化剂体系,在剂料摩尔比1:60,反应温度-60℃、停留时间72 h条件下,制得平均聚合度为20.0,平均分子量为3325 g/mol的全氟聚醚,收率达到99.2%。论文还建立了六氟环氧丙烷阴离子聚合反应的反应动力学模型,模拟了不同工艺条件下的聚合反应过程。为了获得稳定化的全氟聚醚产物,采用碱水解法高效脱除全氟聚醚酰氟端基,获得全氟聚醚油,避免了氟化铝直接催化法的羰基转化问题。优化的稳定化工艺条件为:KOH/二乙二醇水溶液:全氟聚醚=1:3、反应温度100℃,反应时间6 h,再加入2%的A1F3,在250℃反应8 h,得到稳定化的全氟聚醚油。在减压条件下蒸馏切割,获得了不同分子量的窄馏分作为润滑油基础油。油品性质指标测试和真空性能评价结果表明,200-250℃以及250℃的馏分均可作为不同牌号的高端真空泵油。
[Abstract]:Perfluoropolyether is widely used in the field of special compound modification and high-end lubricating oil because of its chemical inert, noncombustibility and low surface tension. But at present, the domestic perfluoropolyether products almost rely on imports. In this paper, perfluoropolyether was synthesized by anion polymerization from hexafluoroethylene propylene oxide (HFPO) and high performance vacuum pump oil was prepared. Firstly, the purification efficiency and adsorption capacity of different combinations of purifying agents were investigated. Anhydrous calcium chloride 3A molecular sieve, calcium oxide and active alumina could reduce the content of HF, water in raw material HFPO to 500 渭 g / g of hexafluoroacetone, respectively, and the content of hexafluoroacetone could be reduced to 2 渭 g / g of hexafluoroacetone, respectively. 300 渭 g / g, meeting the requirements of polymerization. The reaction mechanism of anionic polymerization of hexafluoroethylene oxide was analyzed in this paper. It was shown that the chain growth process was the control step of reaction rate and chain transfer and chain regeneration process determined the degree of polymerization of perfluoropolyether. Maintaining low monomer concentration in the reaction process is beneficial to the polymerization products with high average molecular weight. From the point of view of reaction engineering, the effects of single feed reactor, batch feed reactor and continuous reactor on the polymerization process were investigated. In the continuous reactor, the monomer concentration is low, the dormant concentration is high, and the active agent concentration is low, which is favorable to the polymerization in the direction of high degree of polymerization. The optimum polymerization conditions are as follows: in a continuous reactor, with CsF/DG as catalyst system, the average polymerization degree is 20.0 at molar ratio of 1: 60, reaction temperature of -60 鈩，
本文编号：2330886
[Abstract]:Perfluoropolyether is widely used in the field of special compound modification and high-end lubricating oil because of its chemical inert, noncombustibility and low surface tension. But at present, the domestic perfluoropolyether products almost rely on imports. In this paper, perfluoropolyether was synthesized by anion polymerization from hexafluoroethylene propylene oxide (HFPO) and high performance vacuum pump oil was prepared. Firstly, the purification efficiency and adsorption capacity of different combinations of purifying agents were investigated. Anhydrous calcium chloride 3A molecular sieve, calcium oxide and active alumina could reduce the content of HF, water in raw material HFPO to 500 渭 g / g of hexafluoroacetone, respectively, and the content of hexafluoroacetone could be reduced to 2 渭 g / g of hexafluoroacetone, respectively. 300 渭 g / g, meeting the requirements of polymerization. The reaction mechanism of anionic polymerization of hexafluoroethylene oxide was analyzed in this paper. It was shown that the chain growth process was the control step of reaction rate and chain transfer and chain regeneration process determined the degree of polymerization of perfluoropolyether. Maintaining low monomer concentration in the reaction process is beneficial to the polymerization products with high average molecular weight. From the point of view of reaction engineering, the effects of single feed reactor, batch feed reactor and continuous reactor on the polymerization process were investigated. In the continuous reactor, the monomer concentration is low, the dormant concentration is high, and the active agent concentration is low, which is favorable to the polymerization in the direction of high degree of polymerization. The optimum polymerization conditions are as follows: in a continuous reactor, with CsF/DG as catalyst system, the average polymerization degree is 20.0 at molar ratio of 1: 60, reaction temperature of -60 鈩，
本文编号：2330886
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