紫外分光光度法研究木质素及其系列酯处理含铬酸废水

为了使木质素变废为宝,同时减轻日益严重的水污染问题,以木质素及其酯为吸附剂处理铬酸废水,以期实现以废治废的目的。通过紫外分光光度法研究了不同木质素及其酯处理铬酸废水的工艺和效果。结果表明:木质素处理铬酸废水的较佳工艺为木质素用量0. 4 g/100 m L废水,溶液p H=2,45℃处理4 h。碱木质素对铬酸根的吸附能力较强;酶解木质素、木质素马来酸酯、木质素丁二酸酯为吸附剂时,随着用量的增加,对铬酸根的吸附量增加。而木质素乙酯、木质素丙酯随着用量的增加,吸附量先减小后增加。木质素类型及酯化率差异导致木质素吸附铬酸根的吸附位点数不同,吸附铬酸根离子能力也不同。同类酯的吸附特征相似。木质素的吸附性能与其羟基含量和颗粒结构密切相关。

木质素马来酸酯-醋酸乙烯酯共聚物的制备及性能

以木质素马来酸酯(MLignin)和醋酸乙烯酯(VAc)为原料,通过自由基聚合制备了木质素马来酸酯-醋酸乙烯酯共聚物(MLignin-VAc)。利用FT-IR,GPC,DSC及TG对共聚物的结构、相对分子量、玻璃化温度及热氧降解性能进行了测试表征。测试结果表明:MLignin-VAc红外光谱图中含MLignin和VAc特征基团吸收峰;随着MLignin含量的增加,共聚物的相对分子量逐渐减小,相对分子量分布逐渐增大,玻璃化温度逐渐上升,热氧稳定性基本保持不变。

Performance characterization, of rigid polyurethane foam with refined alkali lignin and modified alkali lignin

The two kinds of rigid polyurethane （PU） foams were prepared with respectively adding the refined alkali lignin and alkali lignin modified by 3-chloro-1,2-epoxypropane to be instead of 15% of the polyether glycol in weight. The indexes of mechanical performance, apparent density, thermal stability and aging resistance were separately tested for the prepared PU foams. The results show that the mechanical property, thermal insulation and thermal stability for PU foam with modified alkali lignin are excellent among two kinds of PU foams and control samples. The additions of the refined alkali lignin and modified alkali lignin to PU foam have little effect on the natural aging or heat aging resistance except for decreasing hot alkali resistance apparently. Additionally, the thermal conductivity of modified alkali lignin PU foam is lowest among two kinds of PU foams and control samples. The alkali lignin PU foam modified by 3-chloro-1,2-epoxypropane could be applied in the heat preservation field.