Preparation And Properties Of Oleic Acid Derived Multifunctional Surfactants

This thesis,illustrates the formation of 9,10-dihydroxystearic acid methyl ester ethoxylate(DHOMEE-n)with different average adduct numbers of ethylene oxide(EO).The path includes the hydrolytic ring-opening of methyl epoxyoleate(EMO)to 9,10-dihydroxy methyl stearate(DHOME)in the first step and its ethoxylated to the DHOMEE-n in the second step.DHOMEE-n possesses the properties of both diol polyether and ester polyether.Besides,taking oleic acid(OA)as raw material,through the epoxidationhydroxylation and ethoxylated reaction,9,10-dihydroxy methyl stearate ethoxylates(DHSAE-n)with different average EO additions was prepared,which has both the properties of fatty alcohol polyoxyethylene ether and fatty acid polyoxyethylene ester.The physicochemical properties and application properties of these two novel nonionic surfactants containing three hydrophilic groups were investigated.The specific content includes the following four parts:(1)The synthesis and identification of DHOMEE-n.Methyl epoxyoleate is used as a raw material to prepare 9,10-dihydroxy methyl stearate(DHOME)by hydroxylation reaction,which has three reactive functional groups(two secondary hydroxyl groups and one ester group),and then its ethoxylated to prepare a series of DHOMEE-n with different average EO additions.The synthesis process of DHOME was optimized and DHOME was purified by recrystallization.The molecular structure of DHOMEE was identified by physical and chemical methods.(2)The physicochemical properties and application properties of DHOMEE-n(n=10,15,20)and different products with the same EO additive number(FMEE-15,OMEE-15,DHOMEE-15)were studied.The results show that DHOMEE-15 has the best ability and efficiency to reduce surface tension,wettability and emulsification performance among the DHOMEE-n with different EO additives.For different products with the same EO number,DHOMEE-15 with two side hydrophilic chains has the best properties.(3)The synthesis and identification of DHSAE-n.9,10-dihydroxystearic acid was prepared from oleic acid by epoxidation-hydroxylation reaction,which has three active functional groups(two secondary hydroxyl groups and one carboxyl group).Then a series of DHSAE-n with different average EO additives were prepared by ethoxylation.The synthesis process of DHSAE was studied and the optimal reaction conditions were optimized.DHSAE was purified by recrystallization.The physical and chemical methods was taken to identify the molecular structure of DHSAE.(4)Performance study of DHSAE-n.The surface properties and application properties of DHSAE-n(n=10,12,15,18,20)were tested.The results show that DHSAE-n is a low foaming and good detergency surfactant.The aggregation behavior of DHSAE-n in aqueous solution was studied.It was found that DHSAE-n can form micelle aggregates in aqueous solution,and the size of micelle aggregates decreases with the increase of EO addition number and solution concentration.