Synthesis Of Alkyl Capped Polyoxyalkylene Carboxylic Ester By Direct Alkoxylation

Alkoxylation is the most common method for adding a nonionic hydrophile compound to an organic hydrophobe one and utilized as an important means for ethylene oxide derived nonionic surfactants manufacture. Fatty methyl ester ethoxylates are receiving significant attention recently due to the product, fatty methyl ester ethoxylates behave similarly to alcohol ethoxylates with some advantages of having a lower foam profile, being less irritating and well biodegradability. This paper deals with the direct synthesis of alkyl capped polyoxyalkylene carboxylic ester which shares much similarities in molecule structure with fatty methyl ester ethoxylate, that is, alkoxylation of carboxylic ester of low or middle-lengthed carbon chain, including triglycerides. A novel poly metal complex catalyst, with magnesium/aluminum as main composition is selected effective alkoxylation catalyst for the alkoxylation of various esters. Middle-lengthed carboxylic ester, methyl caprylate is ethoxylated in the presence of the poly metal complex catalyst above. ESI-MS result demonstrates such ethoxylation is effective and the product octyl methy ester ethoxylate is synthesized with the catalyst activity 0.44gEO/gCat/min.The ESI-MS result also shows that the product possesses the character of narrow range EO adduct distribution and the distribution parameter is over 70. Physical properties is evaluated and the result in general shows the ethoxylated product octyl methyl ester ethoxylate behaves similar cloud point 55.3℃, higher cmc 1.78g/L andγcmc 39.9mN/m but lower foam profile compared to those of lauryl methyl ester ethoxylate. Triglycerides alkoxylate and alkoxylated fats & oil, that is, ethoxylated fats & oil (EFO) and propoxylated fats & oil (PFO) are synthesized directly from triglycerides and natural plant. The catalyst employed exhibits highest activities in the alkoxylation of soybean oil, which reached the points 0.51gPO/gcat/min and 0.71gEO/gcat/min. Triglycerides with ethoxy adduct number about two could be synthesized by ethoxylation in only about 50min from the experiment results. The self-emulsification and emulsification properties of EFO and PFO are examined respectively. Experimental result shows that the emulsifying and self-emulsifying power are enhanced to large extent after the plant oil is alkoxylated and such emulsifying abilities relate to the adduct number. As for the ethoxylated plant oil, its self-emulsifying power is up to 36 times and emulsifying power even more than 140 times of the original plant oil in the range of the research. Formulations of micromulsion containing soybean oil and ethoxylated soybean oil are tested respectively, and its stability is also evaluated. Experiment result demonstrates that the one containing ethoxylated soybean oil shows better thermostability and microemulsifying ability, and possesses higher oil content as well as more board microemulsion phase than the one containing soybean oil, when such formulations are mixed with water to form microemulsion solution. The optimum formulation utilizing ethoxylated soybean oil can form microemulsion with water even at any rate. The low-lengthed carboxylic ester, ethyl acetate is propoxylated by utilizing the novel catalyst above. ESI-MS and GC-MS and IR of the propoxylated product result demonstrates that the poly metal complex catalyst works effectively, which inserts ethylene oxide between the carbonyl carbon and the ester oxygen and propylene glycol ether acetate with other poly proylene glycol ether acetate is synthesized. The effect of catalyst on conversion and selectivity is evaluated, experimental result shows that when the complex catalyst is prepared in the ratio of magnesium/aluminum as 0.65, calcination temperature as 500℃ and calcination time 5h comparatively high conversion and selectivity can be obtained. The experiment result also shows that the best propoxylation temperature and time is 160℃ and 2h, and under these condition above and at the mole ratio of ethylene acetate/propylene oxide 10:1, conversion r...