Preparation And Performances Of Spheric Multifunctional Lignin Based Adsorbent

Lignin is the sole aromatic compound that can be obtained from renewable resources. It is renewable, non-toxic and commercially available, which makes lignin utilization be a valuable work. Nowadays, most lignin applications are based on technical lignins, which are mostly separated during pulping process. In modern paper industry, most useful materials and water rescources can be well reused by the application of advanced treatment technology for the spent liquors of pulping and papermaking. However, a large number of lignin in the spent liquors were used as a source of fuel, or discharged without any treatment process, which caused consequent heavy waste of resources and severe pollution of environment. So, research on the utilization of technical lignin is very important and significant to treat with the watsewater from paper mill and to make full utilazation of natural resource. In order to comprehensively utilize the waste resource of paper industry, the reversed phase suspension polymerization of formaldehyde and lignosulphonate, and the preparation and performances of sphereic lignin based resin were investigated in this paper.The structural characteristics and reactivity of raw material have been studied, the results indicate that the calcium lignosulfonate(CLS) is a mixture of amorphous macromolecule and micromolecule with phenolic lignin units. It comprises many guaiacyl phenols and few p-hydroxy phenols, and most of the units are bonded with ether links. Besides, It comprises a variety of functional groups, such as hydroxyl, sulphonic group, methyoxyl and carbonyl. Mass-average molecular weight of the CLS is 2505, and polydispersity index is 1.55.the reversed phase suspension polymerization of formaldehyde and CLS has been invenstigated systematically, and a spherical lignin-based resin (RLS) with controllable size range in liquid paraffin which is a cheap and non-toxic dispersing medium was developed. The process conditions for the preparation of RLS were optimizd by orthogonal experiments so as to shorten reaction time and to improve the strength and ion exchange capacity of the product. The optimun conditions include 3:1 of phase ratio, 200 r/min of stirring speed, 50% of the CLS concentration, 3mol/L HC1 of acdity, and 7% of formaldehyde dosage and 95℃. The RLS obtained at optimun conditions was characterized with full spheric shape, narrow particle size range, 61.20% of water retention and high adsorptive capacity. 12.5% of form...