以碱木质素(AL)为原料,经1,2-二氯乙烷、亚氨基二乙酸(IDA)改性制得多齿配体改性碱木质素(AL-IDA)吸附材料,用FT-IR、热重和氮吸附技术对其结构进行表征.通过静态吸附实验,考察了pH值、吸附时间、Hg^(2+)和Cd^(2+)初始浓度、温度和共存...以碱木质素(AL)为原料,经1,2-二氯乙烷、亚氨基二乙酸(IDA)改性制得多齿配体改性碱木质素(AL-IDA)吸附材料,用FT-IR、热重和氮吸附技术对其结构进行表征.通过静态吸附实验,考察了pH值、吸附时间、Hg^(2+)和Cd^(2+)初始浓度、温度和共存离子等因素对AL-IDA吸附Hg^(2+)、Cd^(2+)效果的影响.结果表明,溶液pH值对AL-IDA的吸附性能有显著影响,最适宜pH值范围是5.0—6.0;吸附平衡时间为8 h,吸附动力学可以用准二级动力学模型描述和预测;Langmuir方程可以较好地描述AL-IDA对Hg^(2+)、Cd^(2+)的吸附;在pH值为5、初始浓度为300 mg·L-1、温度为25℃时,对Hg^(2+)和Cd^(2+)最大吸附容量分别为239.5 mg·g^(-1)、129.2 mg·g^(-1);温度升高,吸附容量增大,AL-IDA吸附Hg^(2+)、Cd^(2+)的表观活化能分别为22.49 k J·mo1^(-1)和23.28 k J·mo1^(-1),表明吸附主要为化学作用.AL-IDA对重金属Hg^(2+)、Cd^(2+)主要吸附机理是离子交换作用和表面络合.展开更多
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...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.展开更多
文摘以碱木质素(AL)为原料,经1,2-二氯乙烷、亚氨基二乙酸(IDA)改性制得多齿配体改性碱木质素(AL-IDA)吸附材料,用FT-IR、热重和氮吸附技术对其结构进行表征.通过静态吸附实验,考察了pH值、吸附时间、Hg^(2+)和Cd^(2+)初始浓度、温度和共存离子等因素对AL-IDA吸附Hg^(2+)、Cd^(2+)效果的影响.结果表明,溶液pH值对AL-IDA的吸附性能有显著影响,最适宜pH值范围是5.0—6.0;吸附平衡时间为8 h,吸附动力学可以用准二级动力学模型描述和预测;Langmuir方程可以较好地描述AL-IDA对Hg^(2+)、Cd^(2+)的吸附;在pH值为5、初始浓度为300 mg·L-1、温度为25℃时,对Hg^(2+)和Cd^(2+)最大吸附容量分别为239.5 mg·g^(-1)、129.2 mg·g^(-1);温度升高,吸附容量增大,AL-IDA吸附Hg^(2+)、Cd^(2+)的表观活化能分别为22.49 k J·mo1^(-1)和23.28 k J·mo1^(-1),表明吸附主要为化学作用.AL-IDA对重金属Hg^(2+)、Cd^(2+)主要吸附机理是离子交换作用和表面络合.
文摘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.
