Study On The Structure And Property Of Bagasse's Lignosulfonate

Enormous Kraft Lignin and Lignosulfonate produced by straws which are the raw material in pulping and paper making industry await to be utilized every year in china. Lignosulfonate regarded as a anion high molecular compound composed of phenylpropane skeleton as the hydrophobic group and sulfogroup, carboxyl as the hydrophibic group has fine properties of surface activity, adhesive capacity and complexation property etc, thus, it is widely used in agricultural chemicals, dye dispersible agents, chemical agents for tertiary process and fluid-dye emulsifying agent etc in industry. The main conclusions of the analysis of the LsMg's structures and properties together with the entire comparison of the LsMg and LsCa in this thesis based on researches are demonstrated in the following items: 1. In dodecyl amine-octyl purification course, Lignosulfonate could be purified effectually with the yield 88.02% and 85.61% for LsCa and LsMg, respectively, and the Carbohydrate could be removed effectually with the content of saccharide 4.18% and 3.91% for LsCa and LsMg, respectively. 2. Gel Chromatography was chosen to determine the molecular weight distribution of LsMg and LsCa in this thesis. The molecular weight of LsMg mainly concentrated in the range less than 4950 with the occupation of 61.26%, while that of the LsCa were divided into three ranges: less than 4950, 8000 to 18300 and more than 19300 with the occupation of 30.85%, 30.26% and 30.79% respectively. Comparing with LsCa, the low-molecular-weight range of LsMg was far wider than that of LsCa. 3. The content of sulfogroup, carboxyl, phenolic hydroxyl groups and metheoxyl which are the main functional groups in LsMg and LsCa had been determined in this thesis. Except for methoxyl, the content of other groups in LsMg were all more than that in LsCa. By analyzing the elements of LsMg and LsCa, the empirical formula of the C9 in LsCa and LsMg, which were respectively C₉H_8.86O_4.70(OCH₃)_1.81 and C₉H_9.89O_7.52(OCH₃)_1.70 in accordance with the content of methoxyl. 4. The alkali Nitrobenzen oxidation was used to analyze the composition of V unit, S unit and H unit in LsMg and LsCa. The results of the research indicated that: the components of the LsCa in Masson Pine were V unit (14.32%), S unit(trace), and H unit(trace); and the components of the bagasse were V unit (4.83%), S unit(7.61%), and H unit(3.79%). 5. Both LsCa and LsMg can reduce the surface tension of the liquid in some extent, but not obviously. The surface tension descended when the concentration of the LsCa and LsMg ascended. In addition, the ability of LsCa to decrease the surface tension is somewhat stronger than that of LsMg. 6. Both LsCa and LsMg had dispersion on the system of Ti-dioxide and water in which the dispersibility of LsCa is somewhat stronger than that of LsMg. As the amount of LsCa and LsMg increased, the dispersion on the system of Ti-dioxide and water corresponding was improved until the used quantity reaches 1.0%. The dispersion properties of LsCa and LsMg were stable in certain temperature extent, meanwhile, they had better dispersion effect in neutral environment. 7. LsCa and LsMg had adsorption on cement. The adsorptivity of LsMg was better than that of LsCa, while both its foamability and the stability of foaming were inferior to that of LsCa; Also, LsCa and LsMg had slushing on cement. But comparing with sodium naphthalenesulfonate, their effect of slushing was worse. Because of the difference between their molecular weight distributions, LsCa has better effect on slushing than LsMg. While, except the slushing of LsCa rise to a great extent, their adsorptivity, dispersibility and slushing were somewhat improved by modified complexation. All the stats appear that the structures of LsCa and LsMg were slightly varied by complexation with ferricnitrate. 8. LsCa and LsMg also have corrosion mitigation property on carbon steel in the acidity solution. Their effect of corrosion mitigation property trended initial rising to ultimate dropping as the concentration ascended. Research also showed that LsMg acted better than LsCa on it, when the quantity of LsMg reached 0.1%, its maximal value of corrosion mitigation could be up to 43.9%.