缓释型聚羧酸减水剂的低温制备工艺
|
摘要
以异丁烯醇聚氧乙烯醚(HPEG)、丙烯酸(AA)为主要聚合单体,甲基丙烯酸羟乙酯(HEA)部分取代AA,巯基丙酸(MPA)为链转移剂,通过双氧水(H_2O_2)-抗坏血酸(Vc)引发,采用一步合成方法 ,在低温条件下制备了一种缓释型聚羧酸减水剂。研究分析了反应温度、酸醚比、HEA取代量、MPA用量、H_2O_2与Vc摩尔比、滴加时间等因素对合成减水剂产品性能的影响。利用正交试验,筛选出低温条件下较优的合成工艺:反应温度40℃,n(AA)∶n(HPEG)=4∶1,n(HEA)∶n(HPEG)=4.38:1,MPA用量(按HPEG单体质量分数计,下同)为0.65%,引发剂用量为1.17%,n(H_2O_2)∶n(Vc)=2.5∶1,滴加时间3h。当减水剂折固掺量为0.22%时,水泥初始净浆流动度达到280mm,0.5h后净浆流动度达到295mm,1h后净浆流动度达到302mm,相同掺量下与其他减水剂产品相比具有更好的分散性和分散保持性,且胶砂减水率达到37.5%。此外,通过傅里叶红外(FTIR)和热重分析(TGA)等手段对共聚物进行了表征。
Sustained-release polycarboxylate superplasticizer was prepared in one step at low-temperature by using modified polyether macromer(HPEG), acylic acid(AA) as raw materials, AA partly replaced by hydroethyl methacrylate(HEA), mecraptopropionic acid(MPA) as the chain transfer agent, initiated by hydrogen peroxide(H_2O_2)-Vitamin C(Vc). The effect of the reaction temperature, the molar ratio of n(AA) to n(HPEG), the replace amount of HEA, the amount of MPA,the molar ratio of n(H_2O_2) to n(Vc), and the adding time, etc. on the properties of the production were studied. The orthogonal experimental results indicate that the optimum technology of synthesis are shown as follows: the reaction temperature is40℃, n(AA)∶n(HPEG)=4∶1, n(HEA)∶n(AA)=4.38∶1, the MPA addition(based on the weight of HPEG, similarly hereinafter)is 0.65%, the weight of initiator is 1.17%, n(H_2O_2)∶n(Vc)=2.5∶1, and the adding time is 3 h. The results show that the initial fluidity of cement paste can exceed 280 mm, exceed 295 mm after 0.5 h and exceed 302 mm after 1 h when the dosage of polycarboxylate water reducer is 0.22% of cement mass. The polycarboxylate superplastic synthesized has higher dispersity and dispersion retention with the same addition amount than others, and the water reducing rate of mortar reaches 37.5%. In addition, the copolymer is characterized by Fourier transform infrared spectrometer(FTIR) and thermal gravimetric analysis(TGA).
Sustained-release polycarboxylate superplasticizer was prepared in one step at low-temperature by using modified polyether macromer(HPEG), acylic acid(AA) as raw materials, AA partly replaced by hydroethyl methacrylate(HEA), mecraptopropionic acid(MPA) as the chain transfer agent, initiated by hydrogen peroxide(H_2O_2)-Vitamin C(Vc). The effect of the reaction temperature, the molar ratio of n(AA) to n(HPEG), the replace amount of HEA, the amount of MPA,the molar ratio of n(H_2O_2) to n(Vc), and the adding time, etc. on the properties of the production were studied. The orthogonal experimental results indicate that the optimum technology of synthesis are shown as follows: the reaction temperature is40℃, n(AA)∶n(HPEG)=4∶1, n(HEA)∶n(AA)=4.38∶1, the MPA addition(based on the weight of HPEG, similarly hereinafter)is 0.65%, the weight of initiator is 1.17%, n(H_2O_2)∶n(Vc)=2.5∶1, and the adding time is 3 h. The results show that the initial fluidity of cement paste can exceed 280 mm, exceed 295 mm after 0.5 h and exceed 302 mm after 1 h when the dosage of polycarboxylate water reducer is 0.22% of cement mass. The polycarboxylate superplastic synthesized has higher dispersity and dispersion retention with the same addition amount than others, and the water reducing rate of mortar reaches 37.5%. In addition, the copolymer is characterized by Fourier transform infrared spectrometer(FTIR) and thermal gravimetric analysis(TGA).
引文
[1]宋家乐,温宏平,吕长亮,等.聚醚型聚羧酸系减水剂的性能研究[J].混凝土与水泥制品,2011(12):19-21.
[2]李晓东,任萍,李晓燕.常温合成高保坍型聚羧酸减水剂及其性能研究[J].新型建筑材料,2017,44(1):97-99.
[3]ZHANG Rongguo,Guo Huiling,LEI jiaheng,et al.Effect of molecular structure on the performance of polyacrylic acid superplasticizer[J].Journal of Wuhan University of Technology,2007,22(2):245-249.
[4]李顺凯,王文荣,高玉军,等.聚羧酸减水剂常温制备工艺及性能研究[J].新型建筑材料,2016,43(3):37-39.
[5]崔子亮.聚羧酸减水剂的合成和性能研究[D].宜昌:三峡大学,2014.
[6]Hamada D,Sato H,Yamamuro H,et al.Development of slump-loss controlling agent with minimal setting retardation[C].Proceedings of the Canmet/aci International Conference on Superplasticizers&Other Chemical Admixtures in Concrete,2003.
[7]毕耀,韩武军,郑广军,等.复合型聚羧酸减水剂的合成与应用[J].新型建筑材料,2014,41(7):46-49.
[8]郭勇军.使用聚羧酸类减水剂的混凝土泌水调控措施[J].绿色环保建材,2017(6):23-25.
[9]孙振平,郭二飞,曾文波,等.聚羧酸系减水剂常温合成机理研究[J].粉煤灰综合利用,2017(1):8-11.
[10]陈世明,金一丰,高洪军,等.聚羧酸减水剂的常温合成工艺[J].化工进展,2016,35(11):77-91.
[11]仲津男.缓释型聚羧酸减水剂的合成及性能研究[D].西安:西安理工大学,2015.
[2]李晓东,任萍,李晓燕.常温合成高保坍型聚羧酸减水剂及其性能研究[J].新型建筑材料,2017,44(1):97-99.
[3]ZHANG Rongguo,Guo Huiling,LEI jiaheng,et al.Effect of molecular structure on the performance of polyacrylic acid superplasticizer[J].Journal of Wuhan University of Technology,2007,22(2):245-249.
[4]李顺凯,王文荣,高玉军,等.聚羧酸减水剂常温制备工艺及性能研究[J].新型建筑材料,2016,43(3):37-39.
[5]崔子亮.聚羧酸减水剂的合成和性能研究[D].宜昌:三峡大学,2014.
[6]Hamada D,Sato H,Yamamuro H,et al.Development of slump-loss controlling agent with minimal setting retardation[C].Proceedings of the Canmet/aci International Conference on Superplasticizers&Other Chemical Admixtures in Concrete,2003.
[7]毕耀,韩武军,郑广军,等.复合型聚羧酸减水剂的合成与应用[J].新型建筑材料,2014,41(7):46-49.
[8]郭勇军.使用聚羧酸类减水剂的混凝土泌水调控措施[J].绿色环保建材,2017(6):23-25.
[9]孙振平,郭二飞,曾文波,等.聚羧酸系减水剂常温合成机理研究[J].粉煤灰综合利用,2017(1):8-11.
[10]陈世明,金一丰,高洪军,等.聚羧酸减水剂的常温合成工艺[J].化工进展,2016,35(11):77-91.
[11]仲津男.缓释型聚羧酸减水剂的合成及性能研究[D].西安:西安理工大学,2015.