麦草乙醇木素改性制备水泥减水剂的性能研究

Study on Performance of Cement Water-Reducer Prepared by Modified Wheat Straw Ethanol Lignin

麦草乙醇木素通过先羟甲基化提高反应活性,再磺化的方法制备水泥减水剂,研究了改性乙醇木素水溶液的性质及其对水泥的影响,并用红外光谱法测定了乙醇木素改性前后的结构特征。结构表明:改性乙醇木素能提高水泥的净浆流动度,在水灰比为0.35,掺量为0.5%时净浆流动度为200mm。改性乙醇木素显著降低溶液的表面张力,具有表面活性剂的特征。掺入改性产物的水泥减水剂的水泥水化产物钒钙石晶体的生长较少,使得水化硅酸钙结构致密,水泥内部结构更加致密,孔隙较少,水泥渗水性,强度都会有所提高。相比乙醇木素,改性乙醇木素中含有-SO3H的特征吸收峰,乙醇木素发生了磺化反应。

Water-reducer was prepared by hydroxymethylation to activate the ethanol lignin,sulfonation using wheat straw ethanol lignin as raw material.The properties of the ethanol lignin water-reducer solution and it＇s affection on cement were studied.The structure of modified products and the ethanol lignin was characterized by FT-IR.The result showed that,the modified ethanol lignin could improve the fluidity of cement.The fluidity of cement paste with 0.6% modified products was 200mm at water to concrete ratio of 0.35.The modified ethanol lignin with the characteristic of surfactant could decrease surface tension obviously.Cement paste with modified ethanol lignin had little cavansite crystal to grow,so the structure of hydrated calcium silicate was compact,which was beneficial for water permeability and strength of cement.Compared to ethanol lignin,the modified ethanol lignin had the characteristic absorption peak of-SO3H,so sulfonation of ethanol lignin took place successfully.