Preparation Of Carboxymethyl Starch By Semi-dry Process And Its Application In Reactive Dye Printing

It is well reported that Gansu province is the second biggest province in the potato planting area in China.In 2012,the planting area has been reached to 0.7 million hectares.Therefore,there is no doubt that resolving the scientific and technological critical problems in the further processing procedure of potato starch and finding a way out for the products play a important role to the undeveloped Gansu province.Carboxymethyl starch(CMS)is a very important kind of modified starch which has a lot of advantages such as strong hydrophilicity,easy gelatinization,high clarity and viscosity and so on.CMS,honored as "industrial monosodium glutamate",has been widely used in food,drug,petroleum,textile and paper industries.Currently,sodium alginate(SA)could always be used as the paste in the textile printing.However,the natural resources of SA are limited and the cost of SA is expensive.Consequently,searching for the printing paste which can be used as a replacement for the SA is the common research interest among the scholars at home and abroad and also is the technological problem needed to be solved immediately in the textile printing industry.This dissertation uses potato starch(St)as raw material,sodium hydroxide(SH)as catalyst,chloroacetic acid(CA)as etherifying agent,epichlorohydrin(Ep)as cross-linking agent,polyoxyethlene ether(JFC)as penetrating agent,alcohol(Ale)as solvent to synthesize the CMS of high degree of substitution(DS)and viscosity(?)with a semi-dry process in the small(2 L),middle(36 L)and large kettle(3 m3).This is the first time to adopt the genetic algorithm(GA)and the back propagation(BP)to simulate and optimize the reaction conditions of synthesizing the CMS with a semi-dry process in the middle and large kettle.The microstructure of CMS is characterized by fourier transform infrared(FTIR)spectroscope,X-ray diffractometer(XRD),differential scanning calorimeter(DSC)and scanning electron microscope(SEM).We use the CMS synthesized in the large kettle as basic material,compound multiply it with the oxidized guar gum(OGG),carboxymethyl cellulose(CMC)and polyvinylpyrrolidone(PVP)and prepare the compound printing paste(CMS/OGG/CMC/PVP).This is the first time to use the fuzzy mathematics for the quantitative analysis of the handle of the printing fabric and compare the results with the practical properties of product.The primary consequences were summarized as follows:1.The optimum reaction conditions of synthesizing the CMS in the small kettle:mSt= 100 g,nSH/nCA = 2.2,VEp?6 d,VAlc=100 mL,VJFC = 1.9 mL,the each time interval between adding base and acid(?1)= 6 min,the primary total reaction time(t1)= 1 h,the primary reaction temperature(T1)= 35?,the secondary total reaction time(t2)= 4 h;the secondary reaction temperature(T2)= 52?,the rate of agitation(R)= 1000 rpm.2.The DS of CMS synthesized under the optimum reaction conditions in the large kettle is 0.98,the viscosity of 4%(w/w)aqueous solution of CMS is 22000 mPa·s,water content is 9.34%,salt content is 19.02%and the undissolved substance content is 0.23%.3.The experimental results show that the crystalline structures of starch have already been altered from the crystalline region to the amorphous region after carboxymethylation.Carboxymethylation occurs not only on the surface of granule of starch,but also internal part of it.4.The fluid properties of compound printing paste(CMS/OGG/CMC/PVP)belong to the pseudoplastic fluid,the viscosity of 8%(w/w)aqueous solution of this paste is greater than 150000 mPa·s,and it also has the desirable stability,salt resistance,dilutability resistance and holding water capacity.We use compound paste for the reactive dye printing,and the color yield,evenness and fastness of printing fabric are much better than that of fabric using SA solely.Meanwhile,the fabric has the distinct outline of figure and the bright color.The research results indicate that this thesis study and develop this compound printing paste(CMS/OGG/CMC/PVP)which not only can replace the SA in the applying effect,but also has the notable advantage in the price.For the CMS produced by the potato starch and the application on the textile printing paste,these results have not only meaningful reference but also the significant application and potential economic benefit.