Document Type : Research Paper
Authors
1
Department of Polymerization Engineering, Faculty of Engineering, Iran Polymer and Petrochemical Institute, P.O. Box: 14975-112, Tehran, Iran
2
Department of Rubber Engineering, Faculty of Processing, Iran Polymer and Petrochemical Institute, P.O. Box: 14975-112, Tehran, Iran
3
Department of Adhesives and resins, Faculty of Petrochemical, Iran Polymer and Petrochemical Institute, P.O. Box: 14975-112, Tehran, Iran
Abstract
Hypothesis: Water-soluble polymers with different structures are used as additives in cements. The types of functionalities are hydroxy, amine, sulfonate, and carboxylate ions. Polyethylene glycol branches in different sizes and numbers are placed inside the main chain. The design of the mentioned macromolecules is for the synthesis of polymers with different structures and properties. Ionic groups improve the interaction of chains with cement particles and cement dispersion. Branches can lead to better dispersion of cement through steric hindrance mechanism
Methods: A redox radical polymerization reaction was performed with different ratios of acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and TPEG monomers. The structure of synthesized polymers containing different functionalities and branches was characterized by FTIR, 1H-NMR and GPC methods. The interactions between synthesized polymers and cement particles have been investigated by physical sedimentation, zeta potential, and rheological methods
Findings: AM/AMPS copolymers and branched terpolymers containing different functionalities were synthesized and characterized by FTIR, 1H-NMR, and GPC methods. Investigating the interaction of various polymers on the proper dispersion and settling speed of cement particles was done physically. Also, the type of interaction between chains and cement particles was investigated by the zeta potential method. Different types of synthesized polymers with different concentrations showed a significant effect on the rheological behavior of cement suspension. Polymers with different functional groups follow different mechanisms of interaction with cement The important parameters affecting the viscosity and yield stress of the suspension include the amounts of sodium sulfonate ions, polyethylene glycol branches, and Mw of the copolymers. The complex viscosity of the cement slurry in the presence of polymers is pseudoplastic as high as the frequency range of 10 rad/s. The values of tanδ showed that at higher frequencies, the storage modulus of suspensions has an increasing slope, and the response of the system to the applied stress is elastic.
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