木质素的磺甲基化改性及性能测试

Modification of sodium lignosulfonate anmance ted perforst

以木质素、过氧化氢和甲醛为原料,亚硫酸氢钠为磺化剂,通过亲核取代反应制得了磺甲基化木质素(SML),考察反应温度、反应时间、过氧化氢用量和甲醛用量对产物磺化度的影响。通过电导滴定和元素分析法测定了产物的磺化度,并测定了产物的接触角和表面张力,采用环境扫描电镜观察了磺化前后的形貌。结果表明,制备SML的最佳工艺条件为:反应温度80℃,磺化时间7 h,甲醛和过氧化氢用量各为木质素质量的36%,在此条件下,产物的S含量由原来的3.02%增加到7.01%,得到了水溶性良好的SML,并且能够明显的降低煤水界面的接触角。

Using sodium bisulfite as sulfonating agent,the sodium lignosulfonate was prepared from lignin,hydrogen peroxide and formaldehyde. The effects of reaction temperature,reaction time,amount of hydrogen peroxide and amount of formaldehyde on sulfonation degree were investigated. The sulfonation degree of the product was determined by conductivity titration and elemental analysis. Meanwhile the contact angle and surface tension of the product were determined. The morphology of the product was observed by environmental scanning electron microscopy. The result showed that the optimal conditions for the preparation of sodium lignosulfonate were as follows: the reaction temperature 80 ℃,the sulfonation time 7 h,the amount of formaldehyde is 36% of the mass of lignin. Under the above conditions,the sulfonation degree of the product was increased from 3. 02% to 7. 01%,and a water-soluble lignosulfonate salt was obtained.