Application Of Rhamnolipid As Printing And Dyeing Additives

Chemical surfactants are derived from petroleum,which is bound to have an impact on the environment in the process of production and application.It is one of the future development directions to find suitable additives to replace chemical surfactants.As a biological surfactant,rhamnolipid has the characteristics of excellent performance and ecological protection,and is expected to be further applied in printing and dyeing industry.Through studying the performance of rhamnolipid,including surface tension,CMC,permeability,foam properties,emulsification,oil removal performance,dispersion performance,stability,convergence and dispersion of dye/impact on the whiteness of bleached fabric,etc,the application performance of rhamnolipid as scouring agent and soap lotion on pure cotton fabric,and as degreaser on synthetic fabrics are disscussed.Firstly,the surface activity of rhamnolipid was studied.The aqueous solution of rhamnolipid was weakly acidic at room temperature.The surface tension of rhamnolipid was 30 m N/m when the CMC value was 45mg/L.The sedimentation time of 1g/L rhamnolipid solution was 26 s,which indicated that rhamnolipid had good permeability.The solution of rhamnolipid has good foaming property and foaming stability is not easy to break.2g/L rhamnolipid had poor emulsification for liquid paraffin,dimethylsilicone oil and edible oil,but had good oil removal performance.The oil removal rate of 2g/L rhamnolipid solution for edible oil could reach 82%.The calcium soap dispersion index of 2g/L rhamnolipid was 10%.Acid resistance,oxidation,salt performance is good,reduction resistance,alkaline energy is general.The color of rhamnolipid can irreversibly affect the whiteness of bleached fabrics when the treatment temperature exceeds 100?.Rhamnolipid solution had solubilization effect on disperse dyes and had a higher affinity for reactive dyes than water.Secondly,when rhamnolein was used for the scouring of cotton fabrics as scouring agent,the best process was: rhamnolase 2g/L,soda ash 6g/L,40 min,90?.The capillary effect of the fabric under this process is 11.2cm.Compared with the capillary effect directly treated with soda ash under the same conditions of 2.6cm,commercial scouring agent 729 treated with 10.5 cm,obviously the capillary effect of the fabric has been greatly improved and can achieve the scouring effect of commercial scouring agent.The whiteness and capillary effect of the scouring and bleaching process were 80.91 and 12.1cm,respectively.Compared with the scouring and bleaching process,the whiteness of the scouring and bleaching process was 74.4 and 11.4cm,the difference of capillary effect was small,and there was a certain difference of whiteness.Increasing the amount of hydrogen peroxide in the one-bath process could eliminate the color of rhamnolein attached to the fabric.Thirdly,rhamnolipid was used as a soaping agent in the fabric dyed with reactive dyes.The soaping properties of the fabric dyed with reactive HF-GN turquoise blue were analyzed.The optimal soaping process was as follows: concentration of rhamnolipid was 1g/L,soaping temperature was 90?,and soaping time was 15 min.Under this process,rhamnolipid can improve the soap-washing fastness and wet-rubbing fastness by half a level.After soap-washing,compared with the standard sample,the color difference is 0.35 and it has a certain anti-staining effect.Rhamnolipid and commercial soaping agents showed no significant improvement in the soaping effect of fabrics dyed with 5 kinds of reactive dyes.Rhamnolipid has certain adsorption properties on dyes,which is easy to adsorb hydrolyzed and unreacted dyes on fibers and improve washing fastness.Finally,the degreasing properties of rhamnolipid as chemical fiber fabric were discussed.According to its emulsifying properties,the optimal degreasing process was as follows:concentration of rhamnolipid was 2g/L(p H 5.63),temperature was 90?,treatment time was30 min,and bath ratio was 1:10.Under this process,rhamnolipid can remove mineral oil(liquid paraffin)and dimethyl silicone oil by 73% and 85%,respectively.Compared with commercial oil removers,the oil removal effect is not significantly improved,and it has a certain oil removal effect.For rhamnolipid as deoiling agent,it must be thoroughly cleaned after deoiling,the main reason is that rhamnolipid itself has certain contamination to polyester fiber,causing serious influence on dyeing.