Study On Synthesis, Solution Properties And Demulsification Of Comb Structure Fluorine Silicone Surfactant

As the main varieties of special surfactant, fluorine silicon type surfactants have many excellent features such as high surface activity, high and low temperature resistance, weathering resistance, non-toxic and so on. Their molecular structures and properties can be adjusted by the kinds of raw materials and water/oil hydrophilic monomer content, so we can create different kinds of surfactant in accordance with our needs. In recent years, At home and abroad of non-ionic class containing silicon or containing fluorine surfactants were researched mainly on their modification to make their function. Two kinds of surfactant often were researched independently. But these two kinds of surfactants have different advantages, so if they can be integrated into the same molecular structure, there will be a new type of special surfactant. New synthesis fluorine silicon surfactants must have a good application prospect in areas such as aerospace, chemical, textile and oil field because of its good amphiphilic and low use cost.In this paper, a series of non-ionic fluorine silicon surfactants(PFESO) with comb structure was prepared through hydrosilylation method based on polyether hydrophilic monomer, silicone oil containing hydrogen and per-fluorinated octyl ethyl acrylate as the hydrophobic monomer, which is an important exploration of the development of ionic surfactant field. In addition, several series comb silicon surfactants(PESO) were got by adjusting the kinds and ratio of hydrophilic monomers, hydrophobic monomer. This paper is divided into three parts. The first part is related to the study of synthesis and solution properties of the series of amphiphilic comb silicon surfactants(PESO). The second part is mainly about the preparation and properties of the per-fluorinated octyl ethyl acrylate modified amphiphilic comb fluorine silicon surfactants(PEFSO). In the third part, as crude oil demulsifier, the demulsification performance and demulsification mechanism of these surfactants were studied.(1) Polyether as hydrophilic monomer, silicone oil containing hydrogen(PHMS) as the hydrophobic monomer, chloroplatinic acid as the catalyst, various series of amphiphilic comb silicon nonionic surfactants(PESO) were prepared First, a series of silicone surfactant with different ratio of hydrophilic/ hydrophobic monomer was synthesized. Then change the hydrogen content of hydrogen silicone to get different silicone surfactants. After that a series of silicone surfactant were prepared through changing the kinds of polyether. The influence of the type and proportion of hydrophilic / hydrophobic monomer on products’ solution properties was studied. The optimum reaction conditions of synthesis of a series with comb structure non-ionic organic silicon surfactants(PESO) is that catalyst quality percentage of chloroplatinic acid was 0.35%, reaction temperature was 90℃, reaction time was 5 hours. The structure of PESO polymers was characterized via infrared spectroscopy and nuclear magnetic resonance hydrogen spectrum. Then, the effects of hydrophobic group content on surface property of PESO surfactant were studied. In addition, the adsorption behavior of PESO surfactant on the air/water interface and the aggregation behavior of PESO surfactant in aqueous solution were discussed. The size and distribution of PESO micelle were also investigated. The results showed that it is easier for PESO molecules to associate with each other to form micelles with increasing the content of hydrophobic groups, the hydrogen content of hydrogen silicone oil(PHMS) and the ratio(EO/PO) of the polyether. And the average size of micelles increases as well. The surface tension and CMC decreases.(2) Polyether(Y-1) as hydrophilic monomer, silicone oil containing hydrogen(PHMS) and perfluorinated octyl ethyl acrylate(TEAc-8) as hydrophobic monomers, using the same preparation method, a series comb fluorosilicone nonionic surfactants(PFESO) was synthesized. The structure of the product PFESO has been characterized by infrared spectrum. Then, the effects of fluoride monomer content on surface tension and CMC of PFESO surfactant were studied. In addition, the adsorption behavior of PFESO surfactant on the air/water interface and the aggregation behavior of PFESO surfactant in aqueous solution were discussed. The size and distribution of PFESO micelle were also investigated. The results showed that it is easier for PFESO molecules to associate with each other to form micelles with increasing the content of fluoride monomer(TEAc-8). And the average size of micelles increases as well. When the content of TEAc-8 increases from 0‰ to 64.5‰, the value of CMC decreases from 0.646g/L to 0.314g/L. The surface tension is low to 21.61 m N/m. Surface adsorption quantity of PFESO is high to 4.73 μmol/m2. The average size of each surfactant molecules which are adsorbed on the air/water boundary size is only 0.351 nm2. After modified by fluorine monomer, PFESO surfactants have better surface activity than before.(3) The above series of PESO and PFESO was prepared using in crude oil demulsification. Crude oil emulsion should be made in accordance with the water-oil volume ratio 1:1, oil sample was used drop ditch lower bituminous crude oil, water was used distilled water. The effects of demulsifier concentration, temperature, inorganic salt on demulsification were studied by flask test, and using to dehydration rate measure the demulsifier. Results show that when the hydrophilic group is constant, as the increasing of hydrophobic group, the interfacial tension of demulsification increases and demulsification declines.The best demulsifier was PESO-A1. Its dehydration rate was as high as 94.1%. All demulsifier had its appropriate dosage range, that was close to or equal to the CMC. With the of temperature, demulsification of PESO-A1 increases, biggest dehydration rate increases as well, and the time to the maximum dehydration rate was shorten. Salting-out inorganic salt can reduce the PESO- A1 cloud point, so dehydration rate decreases; And Salting-in inorganic salt can improve its cloud point and dehydration rate increases.