Preparation And Research Of Heavy Locomotive Detergent

With the rapid development of high-speed railway,its safety has attracted much attention.The dirt on the train surface will not only increase the friction resistance of the train,but also corrode the surface of the locomotive and endanger the safety.Therefore,the cleaning of the train is particularly important.During the operation of the train,various pollutants are firmly attached to the body surface.The complexity of the pollution sources and the repeated coverage of the pollutants make the cleaning more difficult,so the selection of cleaning agents is more demanding.The purpose of this research is to study an organic concentrated compound enzyme detergent suitable for cleaning the surface of heavy locomotives.Firstly,the detergency ability of 14 surfactants and 4 kinds of enzymes(namely protease,lipase,amylase and cellulase)on the stain simulants including protein stains,oil stains,starch,cellulose and the mixture of four stains was studied through the single-factor experiment.Then,the ratio of the surfactants to the compound enzymes was studied via orthogonal experiments,and the optimal cleaning conditions of the compound enzyme detergent was obtained through the response surface design.Finally,the compound enzyme stabilizer was studied.The main conclusions are as follows:(1)The detergency ability of surfactants on the surface simulant of the heavy locomotive was studied through the single-factor experiment.It was found that the surfactants with a good detergency were sodium dodecylbenzene sulfonate(LAS),fatty alcohol polyoxyethylene ether sulfate(AES),fatty alcohol polyoxyethylene ether(AEO),sodium dodecyl sulfate(SDS),lauroyl amphoteric diacetate disodium(LAD),and nonylphenol polyoxyethylene ether(NPEO).Among them,the AES was best for protein stains with a 85.60% detergency.The LAS had a maximum detergency of 83.38% for oil stains.The SDS showed the maximum detergency of 70.70% on purple-potato starch stains.The LAS had the highest detergency of 75.01% on the vegetable juice which simulates cellulose stains.Starch and cellulose stains are weakly hydrophilic and have a molecular structure similar to that of stain cloths,resulting in an intermolecular force,stronger adhesion and lower detergency.(2)The detergency of the combination of surfactants and enzymes to various stain simulants was studied via the single-factor experiment.It was found that protease 4,protease 5,lipase 3,amylase 3 and cellulase 1showed high enzyme activities at the cleaning condition of 40 ? and p H7.0.The AES added protease 5 had the highest detergency of 99.15% for blood protein stains,which increased by 14.55%.The LAS added lipase 3had the highest detergency of 86.13% for oil stains,which increased by2.75%.The AEO added amylase 3 had the best starch detergency of75.31%,which increased by 9.07%.The SDS added cellulase 1 showed the highest cellulose detergency of 80.91% with an increase of 7.87%.It was found that different surfactants and biological enzymes had a synergistic effect,so it is necessary to compound them.(3)Through the orthogonal experiment,the compound enzyme detergent with the best detergency effect on the stain mixture was A(SDS): B(AES): C(LAS): D(LAD): E(NPEO): F(AEO): G(cellulase1): H(protease 5): I(protease 4): J(lipase 3): K(amylase 3)= 0 : 1 : 3 : 5:3 : 1 : 1 : 0.4 : 0.6 : 0.4 : 0.2.Through response surface analysis and experimental verification,the optimal washing temperature,p H value and the detergency of the compound enzyme detergent were determined as40.1?,7.1 and 86.92%,respectively.To improve the activity of the compound enzyme during the cleaning process,the stabilizer of the compound enzyme was further studied.Polyvinylpyrrolidone,calcium ion,propylene glycol,boric acid and glycerol,which can form a protective film or reinforce the molecular space conformation of biological enzymes,were selected as the stabilizers.The optimum formula of the stabilizers was A(glycerol):B(propylene glycol): C(boric acid): D(polyvinylpyrrolidone):E(calcium chloride)= 25 : 2 : 0.02 : 0.05 : 0.5.Using this stabilizer,the detergency of the complex enzyme detergent was improved by 8%.