甘蔗渣／棉短绒混合浆粕制备高粘级CMC的研究

本文研究甘蔗渣/棉短绒混合浆粕制备高粘级羧甲基纤维素(CMC)的溶媒法工艺。实验表明,纤维素的化学成分、微细结构,特别是碱化条件对 CMC 产品取代均一性有很大的影响。当甘蔗渣/棉短绒的配比为30～40/70～60时,碱比为0. 58～0. 63,酸比为0. 65～0. 68,酒比在2. 0～2. 2的范围内可制得取代度0. 73～0. 75,粘度900～1000mPa·s 的 CMC.用化学和 x-射线衍射分析对醚化机理作了初步探讨,本工艺对利用甘蔗渣原料制高粘级CMC 有经济上和实用上的意义。

A STUDY ON A SLURRY TECHNIQUE OF PREPARING HIGH-VISCOSITY GRADE CARBOXYMETHYLCELLULOSE USING BAGASSE-COTTON LINTER MIXTURE PULP

This paper deals with a slurry technique of preparing high-visco-sity grade carboxymethylcellulose(CMC)using bagasse-cotton lintermixture pulp.It has been concluded that the process of high-viscositygrade CMC and the properties of CMC obtained considerably dependon the purification history,morphology structure and chemical compo-nents of original cellulose fibers.Under the same ratio of monochloace-tate(MCA)to cellulose(W/W)and alcohol to cellulose(V/W),theratio of sodium hydroxide to cellulose and the alkalization conditionsapplied are the primary factors for improving the D.S.uniformity ofCMC obtained.On the other hand,the content of bagasse in the mix-ture pulp from 30% to 40% has not significant influence on the D.S.andviscosity of the product.In order to prepare a CMC with higher unif-ormity,the ratio of reactants,technology of alkalization and etherific-ation etc.must be adjusted carefully.It was found that when the ratioof bagasse pulp to cotton linter is egual to 30-40:70-60 andthe ratio of cellulose to sodium hydroxide to MCA to alcohol is egualto 1:0. 58-0. 63:0. 65-0. 68:2-2. 2,a high viscosity CMC with D.S.inthe range of about 0. 73 to 0. 75 and viscosity(2%aqueous solution)inrange of rbout 900 mpa.s to 1000 mpa.s can be obtained.The mechanismof etherification and the influence of the manner of addition are alsodiscussed through chemical analysis and X-ray technique.This techn-ology method would be useful for saving cotton linter and practical application.