阴-非离子型高分子表面活性剂的制备及性能

Preparation and properties of anionic-nonionic polymeric surfactants

摘要:

以脂肪醇聚氧乙烯醚（AEO）和丙烯酸（AA）为原料，通过酯化反应合成了脂肪醇聚氧乙烯醚丙烯酸酯中间体（AEO-AA），进而与苯乙烯磺酸钠（SSS）和丙烯酸十二酯（LA）通过自由基聚合制备了一种阴-非离子型高分子表面活性剂（P-AASL）。采用FTIR、1H NMR和GPC表征P-AASL的结构组成和相对分子质量分布；采用DLS和TEM表征P-AASL在溶液中的聚集态结构；通过DSC、接触角测试仪器、表面和界面张力测试仪测试了P-AASL的表界面张力、润湿性、耐盐性、热稳定性，并考察了不同m(P-AASL)∶m(石油磺酸钠)（1:9~5：5）对复配表面活性剂体系的表界活性和洗油效率的影响。结果表明，P-AASL属于高分子表面活性剂，其数均分子量（Mn）为12121，重均分子量（Mw）为14027，多分散指数为1.157；P-AASL在水溶液中为分散均匀的球状胶束，平均粒径为141.7 nm，多分散指数为0.136；P-AASL溶液的临界胶束质量浓度为0.62 g/L，最低表面张力为33.4 mN/m；质量分数0.3%的P-AASL溶液可将油水界面张力降低至1×10-1 mN/m，将油湿性天然岩心的水接触角降低至40°以下；P-AASL在300 ℃以上才会发生大量热分解；P-AASL对水溶液中NaCl和CaCl2的耐受度分别为140 g/L的8 g/L；复配表面活性剂体系的复配比例为8∶2时可将原油和水界面张力降低至1×10-3 mN/m的水平，复配比例为5∶5时对原油的乳化分水时间达到50 min以上，复配比例大于3∶7时洗油效率为77%左右。

Abstract:

Fatty alcohol polyoxyethylene ether (AEO) and acrylic acid (AA) as raw materials were synthesized by esterification reaction, and then a negative non-ionic polymer surfactant (P-AASL) was prepared by free radical polymerization with sodium styrene sulfonate (SSS) and dodecyl acrylate (LA). The structure and molecular weight distribution of P-AASL were characterized by FTIR, 1H NMR and GPC. The aggregation structure of P-AASL in solution was characterized by DLS and TEM. The surface interfacial tension, wettability, salt resistance and thermal stability of P-AASL were tested by DSC, contact Angle tester and surface and interfacial tension tester. The effects of different m(P-AASL):m(sodium petroleum sulfonate) (1:9~5:5) on the surface boundary activity and oil washing efficiency of the composite surfactant system were investigated. The results show that P-AASL belongs to the macromolecular surfactant, its number average molecular weight (Mn) is 12121, weight average molecular weight (Mw) is 14027, and polydispersion index is 1.157. P-AASL is a spheroidal micelle with an average particle size of 141.7 nm and a polydispersion index of 0.136. The critical micelle mass concentration of P-AASL solution is 0.62 g/L, and the lowest surface tension is 33.4 mN/m. P-AASL solution with 0.3% mass fraction can reduce the oil-water interfacial tension to 1×10-1 mN/m, and reduce the water-contact Angle of oil-wet natural core to less than 40°. P-AASL thermal decomposition occurs at 300 ℃ or above. The tolerance of P-AASL to NaCl and CaCl2 in aqueous solution was 140 g/L and 8 g/L, respectively. The interfacial tension between crude oil and water can be reduced to 1×10-3 mN/m when the mixture ratio is 8:2, the emulsification water separation time of crude oil is more than 50 min when the mixture ratio is 5:5, and the oil washing efficiency is about 77% when the mixture ratio is more than 3:7.