一种马来酸酐型聚羧酸系减水剂的制备与作用机理的研究

Synthesis of maleate polycarboxylate based superplasticizer and study of the action mechanism

以过氧化苯甲酰(BPO)为引发剂,对氯甲基苯乙烯、马来酸酐(MAH)为聚合单体,采用非均相聚合方法,合成对氯甲基化苯乙烯-马来酸酐共聚物,并通过与蔗糖反应合成苯乙烯-马来酸酐接枝蔗糖共聚物(SP)。通过红外光谱(FTIR)和核磁共振氢谱(1H NMR)对减水剂结构进行表征。并以净浆流动度、水泥颗粒表面吸附量和Zeta电位为指标,研究了其作用机理。结果表明,SP能有效地吸附在水泥颗粒表面,改变水泥颗粒表面的电位,使水泥颗粒表面形成双电子层,在静电斥力的作用下,水泥颗粒之间保持稳定,水泥浆体流动性提高。

A maleate polycarboxylate based superplasticizer（ SP） was prepared from sucrose and 1-（ chloromethyl）-4-ethenyl-benzen-maleic anhydride copolymer（ Cl SMA） through heterogeneous polymerization with benzoyl peroxide（ BPO） as initiator,1-（ chloromethyl）-4-ethenyl-benzen and maleic anhydride（ MAH） as monomer. The molecular structure was characterized by FTIR and1 H NMR. The action mechanism was investigated with initial fluidity,Zeta potential and adsorption as measurement index. The result shows that the mechanism of the SP was mainly owing to that the cement particles adsorbed the SP and SP change the Zeta potential of the surface of cement particle. The electric double layer was formed on the surface of the cement particles. It made cement particles remain stable and improved the fluidity of cement paste,which the action of electrostatic repulsion between different cement particles.