World Journal of Chemical Education
ISSN (Print): 2375-1665 ISSN (Online): 2375-1657 Website: Editor-in-chief: Prof. V. Jagannadham
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World Journal of Chemical Education. 2017, 5(3), 94-101
DOI: 10.12691/wjce-5-3-3
Open AccessArticle

Thermochemistry of Acrylamide Polymerization: An Illustration of Auto-acceleration and Gel Effect

Nedal Y. Abu-Thabit1,

1Department of Chemical and Process Engineering Technology, Jubail Industrial College, Jubail Industrial City 31961, Saudi Arabia

Pub. Date: April 21, 2017

Cite this paper:
Nedal Y. Abu-Thabit. Thermochemistry of Acrylamide Polymerization: An Illustration of Auto-acceleration and Gel Effect. World Journal of Chemical Education. 2017; 5(3):94-101. doi: 10.12691/wjce-5-3-3


Addition polymerization of alkenes is an exothermic process due to the relief of the bond strain from C-C double bonds (π bonds) in the monomer molecules. Control of exothermic reactions is crucial for preventing runaway reactions/explosions in the industrial setting. This experiment was designed for undergraduate students to demonstrate the exothermic nature of addition (chain-growth) polymerization and to estimate the enthalpy of polymerization using adiabatic calorimetry technique. Acrylamide (AAM) was polymerized using ammonium persulfate (APS) and Tetramethylethylenediamine (TMEDA) as redox initiators at room temperature. The concentration of AAM monomer was varied in the range of 5-25 wt. %, and the heat of polymerization was calculated from the recorded temperature rise (ΔT). The enthalpy of AAM polymerization (∆Hp) was estimated to be ≈ 16.5–19 kcal/ mole, depending on the monomer concentration. Enthalpy of polymerization was increased with increasing the monomer concentration due the auto-acceleration effect, which was clearly observed for solutions with AAM concentrations of ≥ 20 wt. %. The auto-acceleration phenomenon was identified from the fast and non-linear increase in the rate of temperature rise which reached a maximum of (0.5°C/ s) for solutions with AAM of 25 wt. %. For AAM concentrations of ≥ 20 wt. %, the auto-acceleration was accompanied by the polymer gelation (gel effect) due to the formation of the high molecular weight polyacrylamides.

polymer chemistry polymerization enthalpy of polymerization redox polymerization polyacrylamide gel effect auto-acceleration norrish-smith effect runaway reaction solution polymerization

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[1]  Hutley, T.J. and M. Ouederni, Polyolefins-The History and Economic Impact, in Polyolefin Compounds and materials. 2016, Springer. p. 13-50.
[2]  Odian, G., Principles of polymerization. 2004: John Wiley & Sons.
[3]  Roberts, D.E., Heats of Polymerization. A Summary of Published Values and Their Relation to Structure. Journal of Research of the National Bureau of Standards, 1950. 44: p. 221-32.
[4]  Norrish, R. and E. Brookman, The Mechanism of Polymerization Reactions. I. The Polymerization of Styrene and Methyl Methacrylate. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1939: p. 147-171.
[5]  Norrish, R. and R. Smith, Catalyzed polymerization of methyl methacrylate in the liquid phase. Nature, 1942. 150(3803): p. 336-337.
[6]  Trommsdorff, V.E., H. Köhle, and P. Lagally, Zur polymerisation des methacrylsäuremethylesters1. Macromolecular Chemistry and Physics, 1948. 1(3): p. 169-198.
[7]  Ozaki, T., et al., The roles of the Trommsdorff–Norrish effect in phase separation of binary polymer mixtures induced by photopolymerization. Polymer, 2014. 55(7): p. 1809-1816.
[8]  O'neil, G.A., M.B. Wisnudel, and J.M. Torkelson, Gel effect in free radical polymerization: model discrimination of its cause. AIChE journal, 1998. 44(5): p. 1226-1231.
[9]  Sepulveda, P. and J. Binner, Persulfate− Amine Initiation Systems for Gelcasting of Ceramic Foams. Chemistry of materials, 2001. 13(11): p. 4065-4070.
[10]  Young, A.C., et al., Gelcasting of alumina. Journal of the American Ceramic Society, 1991. 74(3): p. 612-618.
[12]  Clark, W., et al., An Experiment to Illustrate the Hazards of Exothermic Reaction Scale-Up. Chemical Engineering Education, 2017. 51(1): p. 35-40.
[14]  Kao, C.-S. and K.-H. Hu, Acrylic reactor runaway and explosion accident analysis. Journal of Loss Prevention in the Process Industries, 2002. 15(3): p. 213-222.
[15]  Gustin, J. and F. Laganier. Understanding vinyl acetate polymerization accidents. in INSTITUTION OF CHEMICAL ENGINEERS SYMPOSIUM SERIES. 1999: HEMSPHERE PUBLISHING CORPORATION.
[16]  Gustin, J.-L., Understanding vinyl acetate polymerization accidents. Chemical Health and Safety, 2005. 12(6): p. 36-46.
[17]  Silversmith, E.F., Free-radical polymerization of acrylamide. J. Chem. Educ, 1992. 69(9): p. 763.
[18]  Ohshima, I., et al., Polymerization of acrylamide in the presence of water-soluble nitrogen compounds. 1976, Google Patents.
[19]  Kishore, K. and K. Santhanalakshmi, Thermal polymerization of acrylamide by differential scanning calorimetry. Journal of Polymer Science: Polymer Chemistry Edition, 1981. 19(10): p. 2367-2375.
[20]  Rodriguez, F., et al., Principles of polymer systems. 2014: CRC Press.
[21]  Goren, M.B., Polymerization of acrylamide monomer in the presence of free ammonia and the resulting polyacrylamide product. 1965, Google Patents.
[22]  Benedict, G.D., High molecular weight acrylamide polymer production by high solids solution polymerization. 1975, Google Patents.
[23]  Tareke, E., et al., Analysis of acrylamide, a carcinogen formed in heated foodstuffs. Journal of agricultural and food chemistry, 2002. 50(17): p. 4998-5006.
[24]  Mottram, D.S., B.L. Wedzicha, and A.T. Dodson, Food chemistry: Acrylamide is formed in the Maillard reaction. Nature, 2002. 419(6906): p. 448-449.
[25]  Vannatta, M.W., M. Richards-Babb, and R.J. Sweeney, Thermochemistry to the Rescue: A Novel Calorimetry Experiment for General Chemistry. Journal of chemical education, 2010. 87(11): p. 1222-1224.
[26]  Gordon, M., Reaction kinetics of adiabatic systems. Transactions of the Faraday Society, 1948. 44: p. 196-202.
[27]  Dammers, W., W. Frankvoort, and M. Tels, Temperature-time and temperature-concentration curves in reaction calorimetry. Thermochimica Acta, 1971. 3(2): p. 133-142.
[28]  Zhang, S., et al., Revisiting the mechanism of redox-polymerization to build the hydrogel with excellent properties using a novel initiator. Soft matter, 2016. 12(9): p. 2575-2582.
[29]  Abu-Thabit, N.Y., Chemical Oxidative Polymerization of Polyaniline: A Practical Approach for Preparation of Smart Conductive Textiles. Journal of chemical education, 2016. 93(9): p. 1606-1611.