Polymerization and Performance Investigation of Poly(vinyl alcohol)-g-acrylamide as Gas Hydrate Kinetic Inhibitor

Document Type : Research Article


Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, I.R. IRAN


In present work, poly(vinyl alcohol)-g-acrylamide was synthesized with two initiator systems, which contain ceric ammonium nitrate and ammonium persulfate/sodium metabisulfite redox systems. The structure of the graft copolymers was confirmed by Fourier Transform InfraRed (FT-IR) spectroscopy and ThermoGravimetric Analysis (TGA). The inhibition effects of produced graft copolymers (as new kinetic hydrate inhibitors) and polyvinyl alcohol were investigated on gas hydrate formation with a methane-propane mixture which forms the structure II of the hydrate. In all experiments, the initial pressure was adjusted at 23 bar, temperature at 2 ˚C, and the stirring rate at 400 rpm. All of the tested materials reduce hydrate formation rate and their inhibition strength was PVA-g-AAM1<PVA<PVA-g-AAM2, respectively. Experimental results and kinetics of hydrate formation showed that the PVA-g-AAM1 graft copolymer decreases the average growth rate of hydrate to 11% in comparison with hydrate formation with pure water. Also, PVA-g-AAM2 graft copolymer decreases this rate to 29% which show its more suitable potential as an environmentally friendly new kinetic inhibitor.


Main Subjects

[1] Sloan Jr E.D., Koh, C.  “Clathrate Hydrates of Natural Gases”, 3rd ed., CRC press, New York, (2007).
[2] Varaminian F., Abbasi nia Z., Modeling of Methane Hydrate Decomposition by Using Chemical Affinity, Iran. J. Chem. Chem. Eng. (IJCCE), 29(1): 125-131 (2010).
[3] پارسامهر، صدیقه؛ ورامینیان، فرشاد؛ روستا، هادی، بررسی اثر سینتیکی مبرد R22 در غلظت­های کم بر روی تشکیل هیدرات متان،  نشریه شیمی و مهندسی شیمی ایران، (2)32: 41 تا 45 (1392).
[4] موسوی صفوی، سید محمود؛ منطقیان، مهرداد؛ وفایی سفتی، محسن، بررسی پایداری هیدرات متان در شرایط مختلف دما و فشار، نشریه شیمی و مهندسی شیمی ایران، (1)30: 63 تا 70 (1390).
[5] Parmar A., Pvcap as Kinetic Hydrate Inhibitor in Gas-Water Systems, MSc thesis, University of Bergen, Norway; (2009).
[6] Wang S., “Investigation of Inhibition Performance of Kinetic Hydrates Inhibitors”, MSc Thesis, Curtin University; (2012).
[7] Peng  B.-Z., Sun C.-Y., Liu P., Liu Y.-T., Chen J., Chen, G.-J., Interfacial Properties of Methane/Aqueous VC-713 Solution under Hydrate Formation Conditions, J. Colloid Interface Sci., 336(2): 738-742 (2009).
[8] Reyes F.T., Guo L., Hedgepeth J.W., Zhang D., Kelland M.A., First Investigation of the Kinetic Hydrate Inhibitor Performance of Poly(N‑alkylglycine)s, Energy Fuels, 28(11): 6889−6896 (2014).
[10] Villano L.D., Kommedal R., Kelland M.A., Class of Kinetic Hydrate Inhibitors with Good Biodegradability, Energy Fuels, 22(5): 3143–3149 (2008).
[11] Wu R., Aman Z. M., May E. F., Kozielski K. A., Hartley P. G., Maeda N., Sum A. K., Effect of Kinetic Hydrate Inhibitor Polyvinylcaprolactam on Cyclopentane Hydrate Cohesion Forces and Growth, Energy Fuels, 28(6): 3632−3637 (2014).
[12] Rajput F., “Synthesis and Use of Poly(Vinyl Alcohol) as a Kinetic Inhibitor for Gas Hydrate Inhibition”, MSc Thesis, McGill University; (2015).
[13] Kelland M.A., History of the Development of Low Dosage Hydrate Inhibitors, Review, Energy Fules, 20(3): 825-847 (2006).
[14] Marin E., Rojas J., Ciro Yh., A Review of Polyvinyl Alcohol Derivatives: Promising Materials for Pharmaceutical and Biomedical Applications, Afr. J. Pharm. Pharmacol., 8(24): 674-684 (2014).
[15] Taghizadeh M.T., Mehrdad A., Kinetic Study of Graft Polymerization of Acrylic Acid and Ethyl Methacrylate onto Starch by Ceric Ammonium Nitrate, Iran. J. Chem. Chem. Eng. (IJCCE), 25(1): 1-11 (2006).
[18] Fathi M., Farajollahi A.R., Entezami A.A.,Synthesis of Thermosensitive PVA-g-NIPAAM Nanohydrogels by Radiation Polymerization, New and Advanced Mat. Int. Congr., Isfahan, Iran, Islamic Azad University, Majlesi Branch; (2012).
[19] Mino G., Kaizerman S., A New Method for the Preparation of Graft Copolymers. Polymerization Initiated by Ceric Ion Redox Systems, J. Polym. Sci., 31(122): 242-243 (1958).
[20] Tudorachi N., Lipsa R., Copolymers Based on Poly(vinyl alcohol) and Acrylamide, J. Optoelectronics and Advanced Mat., 8(2): 659 – 662 (2006).
[21]  Lu Y., Jing R., Kong Q., Zhu P., Solid State Grafting Copolymerization of Acrylamide onto Poly(vinyl alcohol) Initiated by Redox System, J. Appl. Polym. Sci., 131(4): 1-7 (2014).
[22] Jha S.K., D’Souza S.F., Preparation of Polyvinyl alcohol-Polyacrylamide Composite Polymer Membrane by ɣ-Irradiation for Entrapment of Urease, J. Biochem and Biophy. Meth, 62(3): 215–218 (2005).
[23] Omidian H., Zohuriaan-Mehr M.J., Bouhendi H., Aqueous Solution Polymerization of Neutralized Acrylic Acid Using Na2S2O5/(NH4)2S2O8 Redox Pair System Under Atmospheric Conditions, Int. J. Polym. Mat. and Polym. Biomat., 52(4): 307–321 (2003).
[24]  Awada H., Daneault C., Chemical Modification of Poly(Vinyl Alcohol) in Water, Appli. Sci., 5(4): 840-850 (2015).
[25] Mishra B. N., Kishore J., Kanthwal M., Mehta I. K., Gamma Radiation Induced Graft Copolymerization of Vinyl Monomers onto Poly(viny1 alcohol), J. Polym. Sci.: Part A: Polym. Chem., 24(9): 2209-2215 (1986).
[26] Da Silva D. A., De Paula R. C. M., Feitosa J. P. A., Graft Copolymerisation of Acrylamide onto Cashew Gum, Eur. Polym. J., 43(6): 2620–2629 (2007).
[27] Traaen, A.H., Some Investigations of Graft Copolymer Formation in Aqueous Solutions of Vinyl Acetate in the Presence of Polyvinyl Alcohol, J. Appl. Polym. Sci., 7(2): 581–589 (1963).
[28] Orakdogen, N., Okay, O., Influence of the Initiator System on the Spatial Inhomogeneity
in Acrylamide-Based Hydrogels, J. Appl. Polym. Sci., 103(5): 3228–3237 (2007).
[29] Roosta, H.,  Dashti, A., Mazloumi, H., Varaminian, F., Inhibition and Promotion Effects of Modified HECs and Modified Starches on the Growth Rate of Hydrate in Methane-Propane-Water System, J. Mol. Liq.,  243: 553–563, (2017).
[30] Willett, J. L., Finkenstadt, V. L., Initiator Effects in Reactive Extrusion of Starch–Polyacrylamide Graft Copolymers, J. Appl. Polym. Sci., 99(1): 52–58 (2006).
[31] Reyes, F.T., Kelland, M.A., Investigation of the Kinetic Hydrate Inhibitor Performance of a Series of Copolymers of N‑Vinyl Azacyclooctanone on Structure II GasHydrate, Energy Fuels, 27: 1314–1320 (2013).
[32] Ajiro, H., Takemoto, Y., Akashi, M., Chua, P. C., Kelland, M.A., Study of the Kinetic Hydrate Inhibitor Performance of a Series of Poly-(N-alkyl-N-vinylacetamide)s, Energy Fuels, 24: 6400–641.