Study On Detergency And Anti-Redeposition Ability Of Sodium Oxalate Builder Formulation

Builders are essential ingredients in detergents,which can quickly remove calcium and magnesium ions in hard water to ensure that surfactants maximize their washing effect.Since sodium tripolyphosphate（STPP）additives can cause eutrophication in water area,it is always an important research direction to find new phosphorus free builders.Sodium oxalate is a kind of binary carboxylate without B,N and P elements.It has good biodegradability,low toxicity and excellent performance in removing calcium ions and determability.It is a potential phosphorus free builder.In order to better understand the application properties of sodium oxalate,this paper further studied the application properties of straight chain surfactant and branch chain surfactant in sodium oxalate washing formulation.Previous studies have found that straight chain sodium dodecyl benzene sulfonate（SDBS）and sodium oxalate detergent formulation ash deposition is serious in the cotton fiber,SDBS has excellent performance and low price,it is the surfactant with the largest amount in current laundry detergent,and cotton fiber is the most widely used clothing fiber.In order to better apply sodium oxalate detergent builder,this paper chooses the biomass sulfonate sodium lignosulfonate（LS）as dispersant to study the effect of SDBS-Na₂C₂O₄-CMC-LS（2/4）detergent formulations on the anti-redeposition performance of cotton fiber.（1）On the basis of studying the positive effect of LS on static and dynamic surface tension of straight chain SDBS,the influence of LS on the detergency of SDBS and sodium oxalate washing formulation was explored,and the results showed that adding LS was beneficial to detersive power.（2）The influence of LS on the anti-redeposition performance of SDBS-Na₂C₂O₄-LS 2/4 and SDBS-Na₂C₂O₄-CMC-LS 2/4 washing formulations was investigated under different LS addition amounts and different washing temperatures.The results showed that LS can effectively improve the ash deposition of cotton fabric.（3）The effects of LS on the crystal structure and particle morphology of SDBSNa₂C₂O₄-LS 2/4 and SDBS-Na₂C₂O₄-CMC-LS 2/4 washing formulation were investigated.The results showed that the ash particles are mixed phase of of calcium oxalate monohydrate and dihydrate,and the ash particles containing LS washing formulations are relatively fluffy.Guerbet alcohol type of branched chain sulfonate（sodium 2-hexyl-l-decane sulfonate,C8）surfactant has good wetting,emulsifying properties and low surface tension,has potential application prospect in household detergent.In this paper,sodium oxalate was used as builder to study the effects of sodium oxalate and LS on the surface tension and detergency of sodium branched-chain sulfonate.Then,the anti-redeposition property of C8-Na₂C₂O₄-LS washing formulation at different washing temperatures was investigated.（1）The effect of sodium oxalate on the surface tension of sodium branched-chain sulfonate C8 was systematically studied,and compared with straight chain SDBS,and the effect of LS on the surface tension of sodium branched-chain sulfonate was investigated.The results showed that sodium oxalate had a positive effect on C8,the equilibrium surface tension(γ_cmc)of sodium branched-chain sulfonate was lower than that of SDBS,and the synergistic effect of LS and sodium branched-chain sulfonate reduced the ycmc and critical micelle concentration cmc of sodium branched-chain sulfonate.（2）By regulating the content of sodium branched-chain sulfonate,sodium oxalate,time,temperature and water hardness of the washing formulation,the influence of the washing formulation composed of sodium branched-chain sulfonate C8 and sodium oxalate on the detergency of three kinds of standard dirty cloth carbon black（JB-01）,protein（JB-02）,setose（JB-03）was studied,and compared with straight chain SDBS.The results showed that compared with straight chain SDBS,sodium branched-chain sulfonate had better detergency power ability for JB-01 and was more suitable for low temperature washing.（3）The effects of LS on the anti-redeposition performance of C8-Na₂C₂O₄-CMC and C8-Na₂C₂O₄-CMC-LS 2/4 washing formulation were studied under different LS addition amounts and different washing temperatures.The results showed that LS can also improve the anti-redeposition property effectively.