Hyperbranched poly amide-ester (HBPAE) was synthesized by a solution condensation polymerization through one-step process using pentaerythritol as a central core and AB2 prepolymerized monomer which was rapidly prepared at room temperature (25°C) using commercially available maleic anhydride (MA) and diethanolamine (DEA) monomers in the presence of p-toluene sulfonic acid as a catalyst. The prepared polymer was characterized by GPC, IR, 1H-NMR, and thermal analysis (TGA and DSC). The influence of the polymer addition to the cement paste was investigated by measuring the effect of 1, 3 and 5 wt% HBPAE solutions on the properties of ordinary portland cement (OPC). Accordingly, several parameters were investigated such as water of consistency, setting times, bulk density, apparent porosity, compressive strength, and combined water content of the polymer/cement pastes. The SEM images proved that the incorporation of HBPAE with the OPC cement did not affect the chemical composition of hydrates, but it only affected the physical state, shape, size, morphology, and crystallinity of the formed hydrates. The results showed that the polymer addition to OPC pastes improved the physicomechanical properties of cement. 1. Introduction In the recent years, significant efforts have been focused on synthesis and application of the hyperbranched polymers as they exhibit many special merits such as highly branched three-dimensional globular architecture, low viscosity, high solubility, abundance of functional end groups, and internal cavities in the molecule, which can be easily designed to meet specific needs in various applications [1–3]. Hyperbranched polymers can be easily prepared in one-step reactions and typically have randomly distributed branches that make them attractive alternatives for numerous applications in comparison with their regular counterparts (dendrimers) which need more expensive and drastic conditions to be properly prepared [4–6]. Hyperbranched polymers are potentially applied in various fields from drug delivery to coatings where increasing scientific interest for them over the past several decades is evident and confirmed by the increasing number of publications [7–12]. The concept of the polymer modification for the cement mortars and concretes is not new, since a considerable research and development of a polymer modification have been performed for the past decades [13, 14]. Consequently, various polymer-based admixtures have been developed to produce the currently popular construction materials because of their good cost-performance balance
References
[1]
S. Wang, S. Tateyama, D. Kaneko, S. Ohki, and T. Kaneko, “Synthesis of well-defined hyperbranched polymers bio-based on multifunctional phenolic acids and their structure-thermal property relationships,” Polymer Degradation and Stability, vol. 96, no. 12, pp. 2048–2054, 2011.
[2]
M. Fischer and F. V？gtle, “Dendrimers: from design to application—a progress report,” Angewandte Chemie International Edition, vol. 38, pp. 884–905, 1999.
[3]
Y. Bao, J. He, and Y. Li, “Synthesis of novel hyperbranched poly(ester-amide)s based on acidic and basic amino acids via “AD + CBB” couple-monomer approach,” Polymer, vol. 53, pp. 145–152, 2012.
[4]
Z. Li, W. Wu, C. Ye, J. Qin, and Z. Li, “New main-chain hyperbranched polymers: facile synthesis, structural control, and second-order nonlinear optical properties,” Polymer, vol. 53, pp. 153–160, 2012.
[5]
T. Wang, M. Li, H. Gao, and Y. Wu, “Nanoparticle carriers based on copolymers of poly(ε-caprolactone) and hyperbranched polymers for drug delivery,” Journal of Colloid and Interface Science, vol. 353, no. 1, pp. 107–115, 2011.
[6]
S. S. Mahapatra, S. K. Yadav, and J. W. Cho, “Nanostructured hyperbranched polyurethane elastomer hybrids that incorporate polyhedral oligosilsesquioxane,” Reactive and Functional Polymers, vol. 72, pp. 227–232, 2012.
[7]
J. M. J. Fréchet, “Functional polymers and dendrimers: reactivity, molecular architecture, and interfacial energy,” Science, vol. 263, no. 5154, pp. 1710–1715, 1994.
[8]
B. I. Voit, “Dendritic polymers: from aesthetic macromolecules to commercially interesting materials,” Acta Polymerica, vol. 46, pp. 87–99, 1995.
[9]
K. M. Lee, J. W. Woo, B. C. Jee et al., “Effect of cross-linking agent and heteropolyacid (HPA) contents on physicochemical characteristics of covalently cross-linked sulfonated poly(ether ether ketone)/HPAs composite membranes for water electrolysis,” Journal of Industrial and Engineering Chemistry, vol. 17, p. 657, 2011.
[10]
S. Y. Jang and S. H. Han, “Preparation of high styrenic sulfonated polySEPS/clay composite film for proton exchange membranes (PEMs),” Journal of Industrial and Engineering Chemistry, vol. 18, no. 4, pp. 1280–1285, 2012.
[11]
D. J. Kim, H. Y. Hwang, S. B. Jung, and S. Y. Nam, “Sulfonated poly(arylene ether sulfone)/Laponite-SO3H composite membrane for direct methanol fuel cell,” Journal of Industrial and Engineering Chemistry, vol. 18, p. 556, 2012.
[12]
S. Kwon, H. Kim, J. W. Ha, and S. Y. Lee, “Prevention of protein and polymeric nanoparticles adsorption using perfluoropolyether,” Journal of Industrial and Engineering Chemistry, vol. 17, no. 2, pp. 259–263, 2011.
[13]
M. Ramli and A. A. Tabassi, “Effects of polymer modification on the permeability of cement mortars under different curing conditions: a correlational study that includes pore distributions, water absorption and compressive strength,” Construction and Building Materials, vol. 28, pp. 561–570, 2012.
[14]
F. Pacheco-Torgal, Abdollahnejad, A. F. A. Cam？es, M. Jamshidi, and Y. Ding, “Durability of alkali-activated binders: a clear advantage over Portland cement or an unproven issue?” Construction and Building Materials, vol. 30, pp. 400–405, 2012.
[15]
Y. Ohama, “Polymer-based admixtures,” Cement and Concrete Composites, vol. 20, no. 2-3, pp. 189–212, 1998.
[16]
F. M. K？l？n？kale and G. G. Dogan, “Performance of concretes produced with superplasticizer,” Journal of Applied Polymer Science, vol. 103, pp. 3214–3219, 2006.
[17]
A. Kapelko, “The possibility of adjusting concrete mixtures “fluidity by means of super plasticizer SNF”,” in Archives of Civil and Mechanical Engineering, 6th edition, 2006.
[18]
I. Papayianni, G. Tsohos, N. Oikonomou, and P. Mavria, “Influence of superplasticizer type and mix design parameters on the performance of them in concrete mixtures,” Cement and Concrete Composites, vol. 27, no. 2, pp. 217–222, 2005.
[19]
D. W. Fowler, “Polymers in concrete: a vision for the 21st century,” Cement and Concrete Composites, vol. 21, no. 5-6, pp. 449–452, 1999.
[20]
B. Chatveera and P. Lertwattanaruk, “Evaluation of sulfate resistance of cement mortars containing black rice husk ash,” Journal of Environmental Management, vol. 90, no. 3, pp. 1435–1441, 2009.
[21]
U. S. Yilmaza and H. Turken, “The effects of various curing materials on the compressive strength characteristic of the concretes produced with multiple chemical admixtures,” Scientia Iranica A, vol. 19, pp. 77–83, 2012.
[22]
A. Amin, H. H. M. Darweesh, S. M. M. Morsi, and M. M. H. Ayoub, “Effect of phthalic anhydride-based hyperbranched polyesteramide on cement characteristics,” Journal of Applied Polymer Science, vol. 120, no. 5, pp. 3054–3064, 2011.
[23]
ASTM C 187-86, American Standard Test Method, 1993.
[24]
STM C 191-92, American Standard Test Method, 1993.
[25]
STM C 191, Standard Test Methods for Time of Setting of Hydraulic Cement by Vicat Needle, 2008.
[26]
ASTM C 170-90, American Standard Test Method, 1993.
[27]
P. C. Hewlett, Lea's Chemistry of Cement and Concrete, John Wiley & Sons, New York, NY, USA, 4th edition, 1998.
[28]
C. Qing-Hua, C. Rong-Guo, X. Li-Ren, Q. Qing-Rong, and Z. Wen-Gong, “Hyperbranched poly(amide-ester) mildly synthesized and its characterization,” Jiegou Huaxue, vol. 27, no. 7, pp. 877–883, 2008.
[29]
S. Hanehara and K. Yamada, “Interaction between cement and chemical admixture from the point of cement hydration, absorption behaviour of admixture, and paste rheology,” Cement and Concrete Research, vol. 29, no. 8, pp. 1159–1165, 1999.
[30]
E. Knapen and D. Van Gemert, “Cement hydration and microstructure formation in the presence of water-soluble polymers,” Cement and Concrete Research, vol. 39, no. 1, pp. 6–13, 2009.
[31]
M. M. H. Ayoub, H. E. Nasr, and H. H. M. Darweesh, “Characterization and utilization of polystyrene and polyacrylamide-graft-methoxypolyethylene as cement admixtures,” Polymer, vol. 45, no. 12, pp. 1307–1315, 2006.
