油酸甲酯乙氧基化物耐酸耐碱性研究

Study on the acid and alkali resistance of oleic acid methyl ester ethoxylate

将油酸甲酯乙氧基化物(OMEE)作为研究对象,通过FT-IR鉴定结构;分别采用国标法和质量法定性、定量测定FMEE和OMEE耐酸耐碱性。由实验结果可知,OMEE与常规饱和脂肪酸甲酯乙氧基化物(FMEE)在结构上存在碳碳双键的差异;国标法不适用于脂肪酸甲酯乙氧基化物耐酸耐碱性的测定;在任意p H值,OMEE的水解率始终高于FMEE;在p H=13时,FMEE和OMEE水解速率最快,且在170 h时OMEE水解完全;FMEE在p H=2~9、500 h时水解率仍小于20%;OMEE在p H小于13时,水解率受p H和时间影响较小。

Oleic acid methyl ester ethoxylate（ OMEE） was characterized by FT-IR. The acid and alkali resistance of fatty acid methyl ester ethoxylate（FMEE） and OMEE were measured qualitatively and quantitatively by national standard method and mass method,respectively. The experimental results show that,the structure of OMEE is different from that of conventional saturated FMEE because of the presence of carbon-carbon double bond. The national standard method is not suitable for the determination of acid or alkali resistance of FMEE.The hydrolysis rate of OMEE is always higher than that of FMEE at any pH. The hydrolysis of both FMEE and OMEE are the fastest at pH 13,and OMEE has been hydrolyzed completely at 170 h. At pH 2 ～ 9,the hydrolysis rate of FMEE is still less than 20 % during the period of 500 h. In additon,the hydrolysis rate of OMEE has been little affected by either pH or time when the pH is less than 13.