Study On Preparation And Properties Of Novel Modified Soybean Phospholipids

Phospholipids are the mixed components extracted from the production of soybean oil,mainly containing lecithin,cephalin,etc.,and each component has a similar skeleton structure.Natural phospholipids are cheap,widely available,and have the role of emulsification,wetting,dispersion,but also has poor hydrophilicity,lack of dispersion and other shortcomings.In this paper,the hydroxyl groups in the common structure of the phosphate esters of phospholipids were connected with polyethylene glycol monomethyl ether to improve its various properties.In this paper,soybean phospholipid powder was used as raw material,acetylation was first carried out to inhibit the activity of primary amine in brain phospholipids structure,and then it was transformed into sodium soy phospholipids.At the same time,polyethylene glycol monomethyl ether 2000(mPEG₂₀₀₀)was converted to polyethylene glycol monomethyl ether p-toluenesulfonate(mPEG₂₀₀₀-OTs).And then modified phospholipids(SP-mPEG₂₀₀₀)was prepared by the reaction of soybean phosphatidic acid and mPEG₂₀₀₀-OTs,so that a long chain of polyethylene glycol monomethyl ether was added to the soybean phospholipid hydroxyl group.The optimum reaction conditions were as follows:soybean phospholipid was reacted with 65 mg NaH to obtain sodium soy phospholipids,the feed ratio was m（sodium soy phospholipids）:m(mPEG₂₀₀₀-OTs)= 0.45:1,the reaction time was 4 hours,the reaction temperature was 90℃,and the conversion rate was 71.2%.The product was a pale yellow solid.Analyzed by 1HNMR and IR,the product was proved to be SP-mPEG₂₀₀₀.This method requires simple reaction conditions and high utilization of soybean phospholipid.The conversion rates of several molecular weight of the mPEG-OTs were close.In contrast,The conversion of the lower molecular weight is higher.The properties of the SP-mPEG₂₀₀₀ were determined.The critical micelle concentration of the aqueous solution was 5×10-4 g/mL,and the surface tension was 42 mN/m.The acid value of SP-mPEG₂₀₀₀ was 5.24.The study of the dispersion force shows that SP-mPEG₂₀₀₀ has better dispersing effect than acetylated soybean phospholipids,which effectively prevents the aggregation of particles.The stability characterization of emulsions formed by SP-mPEG₂₀₀₀ for hexane and water showed that the SP-mPEG₂₀₀₀ had better kinetics stability than acetylated soybean phospholipids and mPEG₂₀₀₀-OTs.It was found that SP-mPEG₂₀₀₀ had good foaming ability and foam stability.The saponification value of SP-mPEG₂₀₀₀ was 70.98.