Synthesis And Application Study Of Modified Soybean Oil For Defoamer

In the field of defoaming agent for waterborne coating, mineral oil defoamer is one of the most important groups of antifoaming agents,but mineral oil defoamer widely have the problem of the low antiforming quality, poor stability. In this paper,we modified soybean oil with polyether and amino silicones, then blends with metallic soap, white carbon black and ethylene bis stearamide based on traditional mineral oil defoamer formula, finally,the antiforming agent with great antiforming performance and high stability were produced.In this thesis, epoxidized soybean oil was synthesized with the material of soybean oil in free solvent, catalyzed by concentrated sulphuric acid and use methanoic acid as peroxide carrier. The optimal condition is as the following:the dosage of methanoic acid is 30% of the oil, the dosage of hydrogen peroxide is 100% of the oil.reacting in 40℃for 4h. The influence of epoxy value on defoaming performance was studied, results the best defoaming performance of epoxy value is 4.62. Then in this thesis, sythesis of polyether modified soybean oil was studied, its materials are PEG400 and epoxidized soybean oil, sulphuric acid is used for activator. The optimal conditions as the following:the dosage of activator is 0.8‰, reacting 140℃for 3h. Effect of block polyether on defoaming performance was investigated, results the best antifoaming performance of block polyether is PEG400 and the best defoaming performance of block polyether is PPG600.In this paper, alcoholysis reaction about soybean oil was studied with the material of soybean oil and carbinol. One element experiments and orthogonal design experiments are carried out to achieve optimized conditions. Finally, The best reaction conditions were the dosage of activator is 1.2‰, reacting 60℃for 3h. Then alcoholysis reaction product were epoxidized with different conditions to obtain the optimum conditions such as the the dosage of methanoic acid and hydrogen peroxide,reacting time,reaction temperature. The optimal condition is as the following:the dosage of methanoic acid is 15% of the oil, the dosage of hydrogen peroxide is 100% of the oil.reacting in 60℃for 5h. The influence of epoxy value and alcoholysis degree on defoaming performance was studied, results the best defoaming performance of alcoholysis degree is the mol of carbinol and soybean oil is 1.5,epoxy value is 4.786. This thesis also synthesize the modified alcoholysis product with amino silicones,its materials were epoxidized alcoholysis product with epoxy value is 4.786 and amino silicones with ammonia value is 1.2mmol/g. One element experiments and orthogonal design experiments are carried out to achieve optimized conditions such as the sorts and amounts of,reacting time and reaction temperature. The optimal condition is as the following:the dosage of solvent alcohol is 50% of the oil, reacting50℃for 5h. Effect of the mol of amino silicones and epoxidized alcoholysis product on defoaming performance was investigated, results the best antifoaming performance of the mol of amino silicones and epoxidized alcoholysis product is 1.25. In this thesis,EBS was synthesized with the material of methyl oleate and ethidene diamine in Two-step. The optimal condition is as the following:the dosage of KOH is 0.8% of the oil, first reacting in 90～100℃dripping ethidene diamine in 1h, then reacting 140℃for 5h.Finally, defoamer obtained by duplicate matches in the experiment with epoxidized soybean oil, metallic soap, white carbon black, ethylene bis stearamide(EBS),modefied soybean oil with PEG400 and PPG600 and amino silicone modefied soybean oil. The defoamer with the optimal antiforming performance is as the following:epoxidized soybean oil is 30%, metallic soap is 15%, white carbon black is 6.5%,EBS is 2%, mineral oil is 7.5%, soybean oil is 10%.