Preparation And Application Of Sapindus Saponin Through Gemini-like Modification

The Sapindus saponin is one kind of natural non-ionic surfactant.Based on the natural,non-toxic,environmental characteristics,it could be widely used in medicine,petroleum chemical industry,daily chemical and other industries.But the current research was limited to extraction and compounding,causing serious waste of resources.Therefore,to further explore and promote the full utilization of sapindus saponinis.As Sapindus mukorossi fruit peel for raw materials,this work discussed the saponin extraction technology and modification process.Then,studied on the surface activity of sapindus saponin and sapindus saponin esters and the compound system with synthetic surfactant.The main research contents are as follows:(1)The Ultrasound-assisted extraction method was firstly used to extract sapindus saponin.To optimize the extract condition of sapindus saponin,The process has been studied by single factor experiment to optimize various process variables such as ultrasonic time,temperature,ethanol volume fraction and solid-liquid ratio.The result showed that the optimal extraction conditions were: 1:6 of material-liquid ratio,90% of ethanol concentration for 20 min at 60°C,the yield rate of sapindus saponin could reach to 20.7%.(2)In order to further improve the surface activity of Sapindus saponin,a gemini-like modification study was carried out to introduce a hydrophobic hydrocarbon chain into the saponin aglycon.Sapindus saponin with acyl chlorides of different chain length and different ratio of sapindus saponin and acyl chloride under alkaline condition.The structures of the sapindus saponin esters were analyzed and confirmed by FT-IR and1 HNMR.The surface activity of the modified sapindus saponin was investigation and the results revealed that esterification with the chain length of C10 and C12 and the ratio of 1:4 and 1:6 produced superior surface activity.compared with the un-modified sapindus saponin,the interfacial tension of saponin is reduced by 40%.(3)The HLB value of sapindus saponin and its modified saponin are between 7-14,which has the functions of wetting,washing and emulsifying;The wetting time of modified sapindus saponin on cotton is 17-32 s,and the time of decanoyl chloride modified saponin(17.9s)is 51.9% shorter than that of sapindus saponin(37.2s);Foaming experiments show that the foaming power of modified saponin is not significantly different from sapindus saponin;The best decontamination effects on cotton and polyester dirty cloths are sapindus saponin-dodecanoyl chloride(48.3%)and sapindus saponin-decanoyl chloride(62.5%),detergency is improved than sapindus saponin but sapindus saponin-caproic chloride(20.1%);With the temperature rising from 30°C to 60°C,the CMC of sapindus saponin wasn’t decline markly;The CMC of saponins was stable at different p H values,and the surface tension of saponin was the lowest at p H 4.(4)Sapindus saponins are mixed with sodium dodecyl sulfate(SDS)and cetyl trimethyl ammonium bromide(CTAB)in proportion.The result showed that the compounding system has a certain synergistic effect,sapindus saponin-decanoyl chloride and CTAB had aggrandize for 23.7%.The wettability of the compound system has been improved,and the foaming efficiency is not significant.