以系列窄分布醇醚 (AEO3/AEO5/AEO7/AEO9) 、氧气和氢氧化钠为原料氧化法合成窄分布醇醚羧酸盐 (AEC3/AEC5/AEC7/AEC9) ,并优化窄分布AEC7 (7EO醇醚羧酸盐) 合成工艺条件,同时考察了系列窄分布醇醚羧酸盐在不同pH值下的表面张力、泡沫性能和润湿性能。结果表明,钯碳负载催化剂用量为醇醚质量的0.4% (以氯化钯计) ,AEC7合成优化条件为:反应温度75 ℃,氧压0.03 MPa,反应转速700 r/min,原料窄分布AEO7与氢氧化钠摩尔比1∶1.02,产率达到93.8%;体系酸碱度对窄分布醇醚羧酸盐性能影响明显,在中性条件下,与AEC3/AEC5/AEC9相比,AEC7表面张力最大为41.66 mN/m;酸性条件下,AEC3 (3EO醇醚羧酸盐) 发泡性最弱,碱性条件下,AEC3发泡性最强;在中性和碱性条件下,窄分布AEC3和AEC5/AEC7/AEC9相比,在润湿和表面张力方面具有明显优势。
A series of fatty alcohol ether carboxylates (AEC) with narrow distribution (AEC3/AEC5/AEC7/AEC9) were synthesized by oxidation and using narrow distribution AEO (AEO3/AEO5/AEO7/AEO9), oxygen and sodium hydroxide as raw materials. The process conditions of synthesis of narrow distribution AEC7 (7EO units) were optimized. The surface tension, foaming performance and wettability of a series of narrow distribution AEC at different pH values were also investigated. The results show that: Given that the palladium carbon supported catalyst is in an amount corresponding to 0.4% of the mass of alcohol ether (by palladium chloride), the optimized conditions to synthesize AEC7 are as follows: the reaction temperature is 75 ℃, the oxygen pressure is 0.03 MPa, the rotating speed is 700 r/min, the molar ratio of narrow distribution AEO7 to NaOH is 1∶1.02, and the yield thus obtained can reach 93.8%; The pH value has significant effects on the properties of AEC with narrow distribution. Among the AECs under investigation, the surface tension of AEC7 being 41.66 mN/m is the highest compared with AEC3/AEC5/AEC9 under neutral conditions; AEC3 (3EO units) has the weakest foaming performance under acidic conditions and the strongest foaming performance under alkaline conditions; Among the narrow distribution AECs, AEC3 has obvious advantages in wetting and surface tension compared with AEC5/AEC7/AEC9 under neutral and alkaline conditions.