摘要
采用过硫酸铵氧化改性的方法降低碱木质素的相对分子质量(简称分子量,下同),增加其分子中的极性基团,制备改性碱木质素基水泥助磨剂GCL6-J,在添加质量分数0.1%(占熟料和混合材料的质量)时使粉磨水泥的45μm筛余值由空白的7.8%降低到5.3%,其助磨效能达到三乙醇胺的89.3%,其对水泥的后期抗折抗压强度达到或超过三乙醇胺,综合性能测定表明,GCL6-J属于一种木质素基高效水泥助磨剂。XPS能谱分析表明,氧化改性使碱木质素在水泥表面的吸附层厚度由氧化前的0.41 nm增加为1.02 nm(以硅原子的能谱分析统计);粉磨水泥样品的C1s质量分数由空白的38.11%降低为34.07%,而Ca2p和Si2p等高能活性点质量分数却由空白的8.51%、4.42%增加为10.29%、4.98%;证明了GCL6-J在水泥新生颗粒表面吸附和电荷屏蔽作用的助磨机理。
The ammonium persulfate is used to oxidize the alkali lignin to prepare oxidized alkali lignin with low molecular weight and more polar functional groups. The prepared high-performance lignin-based grinding aid GCL6 - J is evaluated by grinding experiment, and the results show that the 45 um screen residue values of the milled cements decrease from 7. 8% to 5. 3% at the dosage of 0. 1% （the mass fraction in the total clinker and composite materials） ,which is equivalent to the 89. 3% grinding effect of triethanolamine. The long-term breaking and compression strengths of the milled cement using GCL6 -J reach or exceed those of triethanolamine. The combination property evaluation indicates that the GCk6 -J is a kind of lignin-based high-performance grinding aid. The XPS spectrum analysis shows that the thickness of the adsorption layer of the oxidized alkali lignin is 1.02 nm（ calculated by the Si）,while that of the alkali lignin is 0. 41 nm. The Cls content of the milled cement using GCL6 - J decreases from 38. 11% （blank） to 34.07%, while the Ca2p and Si2p contents increase from 8. 51% and 4. 42% （blank） to 10. 29% and 4. 98% ,respectively, which demonstrates the grinding mechanism of GCI5 -J in the milling process：it adsorbs on the new-born high energy active sites of the cement surface and masks the charge.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2011年第10期1014-1018,共5页
Fine Chemicals
基金
国家杰出青年科学基金(20925622)
国家自然科学基金(21006036)
973项目(2010CB732205)~~
关键词
水泥助磨剂
碱木质素
氧化
抗压强度
助磨机理
建筑用化学品
grinding aid tor cement
alkali lignin
oxidize
compression strength
grinding mechanism
building chemicals
