磺化麦草碱木质素的结构特征及其作为混凝土减水剂的性能  

Structural Characteristics of Sulfonated Wheat Straw Lignin from Alkali Pulping and Its Performances as Concrete Water-reducer

作　　者：庞煜霞[1,2] 杨东杰[1,2] 邱学青[1,2] 邓国颂[1,2] 

机构地区：[1]华南理工大学化工与能源学院 [2]广东省绿色化学产品技术重点实验室,广东广州510640

出　　处：《林产化学与工业》2008年第2期67-72,共6页Chemistry and Industry of Forest Products

基　　金：广东省自然科学基金(05103536、05300211);广东省科技计划(2006B14401006)

摘　　要：研究了碱法制浆副产物麦草碱木质素的磺化产品磺化碱木质素(SWSL)作为混凝土减水剂使用的性能,掺量(相对于水泥的质量分数,下同)为0.25%时,掺SWSL的混凝土减水率达13.5%,较掺木质素磺酸钙(CLS)的(10.2%)高,混凝土3天和7天龄期抗压强度比仅为113%和105%,较掺CLS的(134%和125%)低。SWSL在水泥浆碱性溶液中具有较好起泡性和泡沫稳定性,有较高的减水率,但泡径较粗且分布不均匀,最大泡径为2mm,导致硬化砂浆密度减小,孔径小于0.01mm的气孔比例相对较少,孔径在0.01～0.05mm范围的较多,抗压强度下降。SWSL的磺化度为1.1mmol/g,重均相对分子质量(MW)为4424,较木钙(11370)低。较低的磺化度使SWSL的分散性能比木钙差。The performances of sulfonated wheat straw lignin （SWSL）, which is a sulfonated product of wheat straw lignin extracted from alkali pulping, used as concrete water-reducer were studied. When the dosage is 0.25 % （ based on concrete） , the water-reducing ratio of SWSL reaches 13.5 % which is higher than that of calcium lignosulfonate （CLS） obtained from sulphite pulping; but the 3 and 7 d compressive strengths of concrete are only 113 % and 105 % respectively, which are lower than those of CLS. Further researches indicate that, in the alkali solution of cement paste, SWSL has good foaming property and foam stability, which result in high water-reducing ratio. However the foam of SWSL solution is large and non-homogeneous, with the largest bubble diameter of 2 mm, which leads to decrease of the density of hardened mortar blended with SWSL. The content of pores with a diameter less than 0.01 mm was relatively low; while the content of pores with a diameter between 0.01-0.05 mm was high. Thus the compressive strength of hardened concrete was reduced. The sulfonation degree of SWSL is 1.1 mmol/g and its molecular weight is 4 424 only, which are all lower than those of CLS. The relatively low sulfonation degree is the reason that the dispersibility of SWSL is not comparable with CLS.

关 键 词：木质素 磺化 混凝土 减水剂 

分 类 号：TQ351.013[化学工程] TQ172.46