Research On The Properties And Application Of Biosurfactant Sophorolipids

Biosurfactants have excellent surface properties,good biocompatibility,good biodegradability and other characteristics,and have potential application values in the fields of daily chemicals,environment,medicine,food and textiles.There are many types of biosurfactants,of which sophorolipid(SL)is a promising type of surfactant among glycolipid biosurfactants.In this paper,SL was used as the research object.The physicochemical properties of SL and its compounded systems were measured,and their applications in the pretreatment process of cotton fabric and the cotton fabric soap-washing process were investigated.The main research contents and results were as follows:(1)SL is a low foaming surfactant.Its critical micelle concentration(CMC)is158 mg/L,and it can reduce the surface tension of water to 34.72 m N/m under CMC.The chemical oxygen demand of SL is 52 % lower than that of the penetrant of the same concentration,and the ratio of the five-day biochemical oxygen demand to the chemical oxygen demand is 0.44,indicating that SL has good biochemical properties.The compounding ratio of the compounded systems SL/SDBS and SL/RL was optimized.Under the optimized compounding ratio,the wetting time of SL/SDBS and SL/RL on cotton canvas is less than 10 s,the emulsifying performance is also increased by 6 % and 27 %,respectively,and the effect of alkali(sodium hydroxide)resistance is very significant,both reaching 35 g/L.(2)In one-bath method and three-step process,the application effect of the compounded systems SL/SDBS and SL/RL are better than using SL alone.Compared with the traditional three-step process,the application effect of the compounded systems SL/SDBS and SL/RL in one-bath method is better than that of high-efficiency scouring agent,and the performances of cotton fabrics have been improved.From the perspective of energy saving and environmental protection,the one-bath method can replace the traditional three-step process.(3)The compounded system SL/SDBS has the most obvious soaping effect on reactive dyed cotton fabric.When the dye amount is 5 %,the soaping effect of the SL/SDBS is 62 % higher than that of sodium dodecylbenzenesulfonate.When the dye amount is 2 % to 4 %,the soaping effect of the compound system SL/RL is better than that of sodium dodecylbenzenesulfonate.Adding polyvinylpyrrolidone,sodium carboxymethylcellulose,sodium carbonate,and sodium silicate to the compounded systems SL/SDBS and SL/RL,they have a certain builder effect on the two compounding systems.Polyvinylpyrrolidone has the most outstanding builder effect.It improves the soaping effect of the compounded systems SL/SDBS and SL/RL by3.8 % and 3.6 %,respectively,and improves the cotton fabric rubbing fastness and soaping fastness by 0.5 to 1.0.The above conclusions show that SL has excellent surface activity,and the synergistic effect of SL with SDBS and RL can effectively improve its performance.SL compounded systems have certain application value in the pretreatment process of cotton fabric and the cotton fabric soap-washing process.This research provides certain theoretical basis for the development and application of SL in the field of textile dyeing and finishing.