对氯甲基苯乙烯-马来酸酐接枝蔗糖共聚物减水剂的制备

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(FI-IR)和核磁共振氢谱(¹H NMR)对减水剂结构进行表征.并以净浆流动度为指标设计正交试验,考察了取代反应的反应温度、反应时间和催化剂用量等工艺条件对SP净浆流动度的影响.结果表明:当取代反应的反应温度为45℃,反应时间为2h,催化剂用量为10%时所得制品的减水性能最佳.以正交试验最佳取代反应条件得到的SP,具有良好分散性,在掺量为0.3%时,净浆流动度为320mm,减水率为27.9%.

Synthesis of 1-(chloromethyl)-4-ethenyl-benzen - maleic anhydride grafted sucrose superplasticizer

1-(chloromethyl)-4-ethenyl-benzen-maleic anhydride grafted sucrose superplasticizer (SP) was prepared from sucrose and 1-(chloromethyl)-4-ethenyl-benzen-maleic anhydride copolymer (ClSMA) through heterogeneous polymerization with benzoyl peroxide (BPO) as initiator,styrene and maleic anhydride (MAH) as monomers. The molecular structure was characterized by FI-IR and ¹H-NMR. Effects of the reaction temperature,reaction time and degree of catalyzer on the substitution reaction were investigated with the initial fluidity as measurement index. The result shows that the optimal condition of substitution reaction includes that the amount of catalyst is 10% according to the mass of sucrose and 1-(chloromethyl)-4-ethenyl-benzen-maleic anhydride copolymer,the reaction temperature is 45℃ and reaction time is 2h. SP prepared under optimal condition has good plasticizing property,the initial fluidity of cement paste reaches 320mm,and the water-reducing ratio is 27.9%.