α-甲基丙烯酸混合醇酯-马来酸酐-苯乙烯降凝剂的制备及其降滤效果评价

Preparation of Methacrylic Acid Ester-Maleic Anhydride-Styrene as Pour Point Depressant and Their Effects on Cold Filter Plugging Point Depression

采用自由基溶液聚合法合成了α-甲基丙烯酸混合醇酯(AE)-马来酸酐(MA)-苯乙烯(St)三元共聚物(AMS)降凝剂;考察了AMS的最佳聚合条件及其对中原0#柴油和燕化0#柴油的降滤效果;用GC技术分析了中原0#柴油和燕化0#柴油中正构烷烃碳数的分布;用1HNMR技术表征了AE和AMS的结构。AMS的最佳聚合条件为:n(AE)∶n(MA)∶n(St)=3∶1∶1,时间5h,温度80℃;AMS降凝剂的适宜添加量(占柴油的质量分数)为0.08%,此时中原0#柴油和燕化0#柴油的冷滤点降幅分别为4℃和6℃。对于正构烷烃含量较低、正构烷烃碳数分布较宽且较均匀的柴油,使用AMS降凝剂时,降滤效果较好。

Methacrylic acid ester （AE） -maleic anhydride （ MA ） -styrene （St） terpolymer （ AMS ）, used as pour point depressant for diesel fuel, was synthesized through free radical solution polymerization. Effects of AMS on cold filter plugging point depressions of Zhongyuan 0# diesel fuel and Yanhua 0# diesel fuel were investigated. The n-paraffin distributions of the tested diesel fuels were analyzed by means of GC. The structures of AE monomer and AMS terpolymer were characterized by means of 1H NMR. Optimum conditions for AMS synthesis were： n（AE） ： n（MA） ： n（St） 3 ： 1 ： 1, reaction time 5 h and reaction temperature 80 ℃. Addition of AMS obtained under the optimum conditions can reduce the cold filter plugging points of Zhongyuan 0# diesel fuel and Yanhua 0# diesel fuel by 4 ℃ and 6 ℃ respectively when dosage of AMS is 0.08% （mass fraction based on diesel fuel）. AMS is more efficient for the diesel fuel with lower n-paraffin content, and broader and well- proportioned n-paraffin distribution.