酸性可溶木质素胺的合成及其乳化性能研究

Preparation and Emulsifying Performance of Acid-soluble Aminated Lignin

以碱木质素、甲醛和二乙烯三胺(DETA)为原料经过Mannich反应制备木质素胺。采用元素分析、红外光谱和核磁共振等方法对木质素胺的结构进行了表征,并分析了其溶解性能和乳化性能。红外光谱和核磁共振氢谱分析证明了DETA被成功地接枝到木质素的苯环上。合成条件优化时发现反应温度和反应时间对枝接率影响较小,而原料比的影响较大,在温度为80℃、反应时间6 h、甲醛和DETA物质的量比值为3.0、DETA和木质素质量比值为1.55条件下,木质素胺的含氮量最高可达16.95%。同时性能测试结果表明:木质素胺在酸性水溶液中的溶解性与其接枝率有明显的相关性,当木质素胺的含氮量达到16.59%以上时,其在酸性条件下的溶解性达到100%。将木质素胺制备成质量分数为5%、pH值为2的酸性皂液,并制备含固体62%的乳化沥青,经检测,木质素胺的酸性水溶性越好,其乳化沥青性能也越好;当木质素胺的含氮量达到16.95%,乳化沥青的筛上剩余量为0,1 d和5 d贮存稳定性分别小于1%和5%,颗粒的平均粒径均达到2.2μm。

The aminated lignin was prepared by Mannich reaction with alkali lignin,formaldehyde and diethylenediamine（DETA） as the raw materials. The structure of aminated lignin product was characterized by elemental analyzer,infrared spectrometer and nuclear magnetic resonance instrument,and its solubility and emulsifying properties were analyzed. The infrared spectrum and 1H NMR spectrum analyses also demonstrated that the diethylenediamine was successfully grafted to the benzene ring of lignin.The grafting rate was less affected by temperature and time and more affected by raw material ratio. When the temperature was80 ℃,the reaction time was 6 h,the molar ratio of formaldehyde and DETA was 3 and the mass ratio of DETA and lignin had1. 55,the nitrogen content of aminated lignin could reach the maximum of 16. 95 %. The experimental results showed an obvious correlation between the grafting rate and solubility in acidic solution. When the nitrogen content of aminated lignin reached above16. 59 %,its solubility in acid conditions reached 100 %. The acid soap solution was prepared by using aminated lignin in the mass fraction of 5 % and the pH value of 2,and the asp Halt emulsion was prepared in the concentration of 62 % using this acid soap solution. As the examination results showed,the better solubility of aminated lignin had,the better performances of the asp Halt emulsion had. When the nitrogen content of lignin reached above 16. 95 %,the residual volume of asp Halt emulsion was 0,and the storage stability of 1 and 5 days was less than 1 % and 5 %,respectively. The average particle size of the emulsion reached 2. 2 μm.