Synthesis and Application Performances of Solid Polycarboxylate Superplasticizers Using Different Initiators

Abstract:

At present, the products of polycarboxylate superplasticizer (PCE) mainly present liquid state. Compared with liquid PCEs, solid PCEs have not only high storage stability, but also high water-reducing rate. Based on acrylic acid (AA) and isobutenyl polyethylene glycol (IPEG) as the main materials, a series of solid PCEs were synthesized under anhydrous condition by employing ammonium persulfate (APS), benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN) and azobisvaleronitrile (ABVN) as initiators, and the effects of different initiators on the application performances of these solid PCEs were also investigated. The molecular characteristics of the synthesized products were determined by Infrared Spectroscopy (IR) and molecular weight measurements to confirm the expected structure. The fluidities, dispersions and micro-observations of cement pastes containing solid PCEs were evaluated. For both liquid PCE and PCE-ABVN, the average particle size reduced from 2373nm to 1147nm. The results showed that the paste fluidity, concrete slump and retentions were significantly enhanced when using ABVN as initiator, with the initial slump up to 225mm. This initiator had high initiating efficiency, exhibiting broad application prospects.

• Periodical: Materials Science Forum (Volume 993)
• Pages: 1367-1372
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.993.1367
• Online since: May 2020
• Authors: Xiao Liu*, Xia Bing Bai, Qian Xu, Chun Lei Xia, Guang Hong Lai, Jia Nan Guan
• Keywords: Adsorption, Cement-Based Material, Dispersion, Initiator, Polycarboxylate Superplasticizer

References

[1] Kong F. R., Pan L. S., Wang C. M., et al. Effects of polycarboxylate superplasticizers with different molecular structure on the hydration behavior of cement paste[J]. Construction and building materials, 2016, 105: 545-553.

DOI: 10.1016/j.conbuildmat.2015.12.178

[2] Zhou X. Y., Gao J. B. Causes and solutions of wall sticking in spray drying[J]. Application of chemical, 2007(6): 599-602.

[3] Tao J, Ni T, Xia L. L., et al. Study and performance evaluation of solid polycarboxylic acid water reducer synthesized by bulk polymerization[J]. Chemical progress, 2017, 37(5): 288-293.

[4] Zhang T, Shang S, Yin F, et al. Adsorptive behavior of surfactants on surface of Portland cement[J]. Detergent & Cosmetics, 2001, 31(7): 1009-1015.

DOI: 10.1016/s0008-8846(01)00511-7

[5] Chen S. M, Jin Y. F, Gao H. J., et al. Synthesis process of polycarboxylic water reducer at ambient temperature[J]. Chemical Industry and Engineering Progress, 2016, 35(11): 3645-3649.

[6] Wang H. P., Chen Z. G. Status and development of polycarboxylate type superplasticizer[J]. Chinese Journal of Colloid & Polymer, 2004, 23(4): 12-15.