碱木素改性及其减水分散性能的研究

针对碱木素的结构特性，采用预氧化磺化反应对碱木素进行化学改性。研究了改性碱木素作为混凝土减水剂的减水分散生能，结果表明，改性后碱木素的物化性能和应用性能得到较大改善。掺入改性产品的水泥净浆具有流动度损失小的优点，2h内的流动度损失率率只有36％；在低掺量下，磺化碱木素初凝时间比空白水泥略长，终凝时间延缓3.5h。当掺入水泥质量0．2％（绝干量）的减水剂，水泥净浆的28天抗压强度比为115％，作为废物排放的碱木素可以改性为一种具有低流动度损失，缓凝，能提高混凝土后期强度等特点的低成本普通混凝土减水剂。

Study on Modification of Alkali Lignin and its Water-reducing and Disperse Properties

In view of the characteristics of alkali lignin, preoxidized sulphonation was specially designed to improve the properties of the alkali lignin. The properties of alkali lignin as a water reducing agent of concrete were measured. The testing result shows that the physicochemical characterization and applied properties of alkali lignin were improved obviously after modification. The fluidity loss ratio of the cement paste with sulphonated alkali lignin within two hours is only 36%, which indicats the sulphonated alkali lignin has small slump loss of concrete. At a low blend ratio of 0.2% (absolutely dry weight), 28 days compressive strength ratio is 115%. As a result, a low cost common water reducing agent of concrete can be prepared via modification using alkali lignin as primary waste material.