摘要
玉米淀粉经酸解处理后,经次氯酸钠氧化、环氧乙烷醚化,制备出氧化-醚化淀粉,对其在水泥中的减水分散效果进行了研究,并通过红外光谱、流变仪及zeta电位等测试对其改性效果进行表征。结果表明:玉米淀粉分子链上被成功引入了羧基和羟乙基醚,在羧基含量为0.48%时醚化度(摩尔取代度MS)为0.5时减水剂分散能力最好。相同掺量下,氧化-醚化淀粉型减水剂减水效果明显优于萘系减水剂。氧化-醚化淀粉掺量为0.6%～0.8%时,减水效果最好。氧化-醚化淀粉的zeta电位值为-11.4mV明显低于萘系的-36.7mV,说明其减水分散能力是通过阴离子羧酸基团的吸附作用,并主要靠较大分子量及其分子链中葡萄糖单元环的空间位阻来分散水泥颗粒。
The oxidized-etherified starch（OES） was prepared by corn starch via a sequebtial process of acidolysis treatment,sodium hypochlorite oxidation and oxirane etherification.The effect of water-reducing characteristic on the cement paste and the dispersion of the OES in the paste were investigated.The modification effect was characterized by Fourier transform infrared spectrometer（FTIR）,rheometer,and zeta potential measurement.The results show that the carboxyl and hydroxyethyl ethers are grafted on the molecular chain of the corn starch and the dispersion effect of the water-reducing agent is superior at the carboxyl content of 0.48% and the etherification degree（MS） of 0.5.The water-reducing effect of the OES water-reducing agent was better than that of the sulfonated naphthalene formaldehyde.The water-reducing effect of the OES is superior at the contents of 0.6%-0.8%.The zeta potential of the OES was-11.4 mV,which was greater than that of the naphthalin series water-reducing agent（-36.7 mV）.The dispersion effect of the OES mainly depended on the absorption of the anion carboxylic acid group,the large molecular mass and steric of the glucose unit in the molecular chain.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2010年第7期1191-1196,共6页
Journal of The Chinese Ceramic Society
基金
国家科技攻关计划(2006BAF02A24)
校重点项目(07XJGZB02)资助
