نوع مقاله : پژوهشی
نویسندگان
تهران، پژوهشگااه پلیمر و پتروشیمی ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Hypothesis: water-soluble polymers with different structures are used as additives in cement. 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 led to better dispersion of cement via steric hindrance mechanism.
Methods: The 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 branch was characterized by FTIR, HNMR and GPC methods. The interactions between synthesized polymers with cement particles was investigated by physical sedimentation, zeta potential and rheological methods.
Findings: AM/AMPS copolymers and branched terpolymers containing different functionalities were synthesized. Study of the interaction of various polymers on proper dispersion and settling speed of cement particles was done physically. Also, the type of interaction between chains and cement particles was investigated by zeta potential method. Different types of synthesized polymers with different concentrations have a significant effect on the rheological behavior of cement suspension. The polymers with various functionalities have different mechanisms of interactions with cement. The important parameters affecting the viscosity values 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 up to the frequency range of 10 rad/s. The values of tan 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 an elastic.
کلیدواژهها [English]
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