以马来酸酐(MAH)和β-环糊精(β-CD)进行酯化反应制备了马来酸-β-环糊精(MAH-β-CD),讨论了n(MAH)∶n(β-CD),反应时间及反应温度对MAH-β-CD产率的影响.结果表明,当n(MAH)∶n(β-CD)为10∶1,反应温度为90℃,反应时间为8h时,MAH-β-CD产率为75％(质量分数).以丙烯酸(AA)、烯丙基聚乙二醇(APEG)、甲基丙烯磺酸钠(MAS)和MAH-p-CD为原料,通过自由基共聚反应制备了一种含β-CD侧基聚羧酸系减水剂(RPC).基于水泥净浆流动度测试结果,确定共聚反应单体摩尔比n(AA)∶n(APEG)∶n(MAS)∶n(MAH-β-CD)为5.000∶1.000:0.500∶0.075,引发剂过硫酸铵(APS)用量为单体总量的5％(质量分数),反应温度为80℃,反应时间为5h.用FTIR和1H-NMR对MAH-β-CD和RPC的化学结构进行了表征.对RPC在混凝土中的应用性能进行了探讨,结果表明:RPC缓凝时间为5h,减水率大于32％(质量分数)；掺入RPC后,混凝土早期抗压强度增长较快,新拌混凝土未出现泌水、离析现象.%β-cyclodextrin grafted maleic anhydride(MAH-β-CD) was synthesized by esterification of maleic anhydride(MAH) and β-cyclodextrin(β-CD). The effect of n(MAH) :n(β-CD), reaction time and reaction temperature on the yield of MAH-β-CD was investigated. The results show that the yield of MAH-β-CD is 75%(by mass) when the n(MAH):n(β-CD) is 10:1 and reaction is carried out at 90 ℃ for 8 h. A new set retarding-type polycarboxylate superplasticizer(RPC) was prepared by free radical solution copolymeriza-tion of acrylic acid(AA), allyl polyethylene glycol ( APEG) , sodium methylacrylsulfonate ( MAS) and MAH-β-CD. Based on the test result of fluidity of cement paste, the synthesis process of RPC is carried out at the n(AA):n(APEG):n(MAS):n(MAH-β-CD) = 5. 000:1. 000:0. 500:0. 075 in the presence of 5% (mass fraction of monomers) APS at 80 ℃ for 5 h. The chemical structure of MAH-β-CD and RPC was characterized by FTIR and 1 H-NMR. The application result in concrete for RPC indicates that the set retarding time is 5 h longer and water reducing rate is as higher as 32%(by mass). The concrete with RPC does not show any segregation and bleeding, the early compressive strength is improved significantly.
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