Nanocomposite Hydrogel Stoppers for Preventing the Natural Gas Leakage During the Welding

Document Type : Research Article


1 Chemical Engineering Department, Urmia University of Technology, P.O. Box 57155-419, Urmia, I.R. IRAN

2 West Azarbayjan Gas Company, P.O. Box 57155-334, Urmia, I.R. IRAN


In this research, a novel generation of stoppers for in-service natural gas distribution and transportation pipelines was prepared on the basis of nanocomposite hydrogels for preventing the gas leakage during the welding operation. The nanocomposite hydrogel stoppers were prepared on the basis of polyvinyl alcohol as the matrix phase and montmorillonite nanoclay as the reinforcing phase. Some structural, physical and mechanical properties of the prepared stoppers were experimentally investigated and their dehydration kinetics and the stopping performances were also evaluated. The results showed that the nanocomposite hydrogel stoppers possibly had an exfoliated morphology and the presence of montmorillonite in their structures increases the crosslinking and improves the mechanical properties (up to 280% increase in the elastic modulus and a 43% decrease in the elongation at break). The results obtained from the dehydration tests demonstrated that the weights of prepared stoppers are reduced to 60-70 % of their initial weights during the first hour of the dehydration process. The results obtained from the stopping performance showed that the prepared nanocomposite hydrogel stoppers could undergo the gas pressure up to 9 psi. It was observed that the stopping ability and the maximum endurable pressure of the prepared nanocomposite hydrogel stoppers are increased by increasing the diameter and length of the stopper. The accomplished experiments for investigating the stopping ability of the nanocomposite hydrogel stoppers proved their unique performances in perfect sealing and preventing gas leakage in natural gas pipelines. In general, it can be expressed that the prepared nanocomposite hydrogels are suitable candidates to be used as novel stoppers during the welding operation in the natural gas distribution and transportation pipelines.


Main Subjects

[1] Treloar R.D., “Gas Installation Technology”, Second Edition, John Wiley & Sons, Inc., United Kingdom (2010).
[2] Amend B., Bruce W.A., Welding on In-service Pipelines: Dispelling Popular Myths and Misconceptions, Can. Welding Assoc. J., Spring: 30-39 (2013).
[3] کیوان­پور، علی؛ صرفه­نیا، منوچهر؛ "ایمنی گاز طبیعی در شبکه­های گازرسانی و ایستگاه­های تقلیل فشار"، آموزش نیروی انسانی شرکت ملی گاز ایران (1382).
[4] نوبخت اصل، فاطمه؛ کردتبار، مهران، سنتز و شناسایی هیدروژل‌های ابر جاذب نانوکامپوزیت مغناطیسی آهن بر پایه صمغ زانتان اصلاح شده با استفاده از اکریلیک اسید، نشریه شیمی و مهندسی شیمی ایران، 35: 33 تا 38 (1395).
 [5] Byrne M.E., Park K., Peppas N.A., Molecular Imprinting Within Hydrogels, Adv. Drug Delivery Rev., 54: 149-161 (2002).
[6] Ganji F., Vasheghani-Farahani S., Vasheghani-Farahani E., Theoretical Description of Hydrogel Swelling: A Review, Iran. Polym. J., 19: 375-398 (2010).
[7] Peppas N.A., Bures P., Leobandung W., Ichikawa H., Hydrogels in Pharmaceutical Formulations, Eur. J. Pharm. Biopharm., 50: 27-46 (2000).
[8] Mohammad Beigi S., Babapoor A., Maghsoodi V., Mousavi S.M., Rajabi N., Batch Equilibrium and Kinetics Studies of Cd (II) Ion Removal from Aqueous Solution Using Porous Chitosan Hydrogel Beads, Iran. J. Chem. Chem. Eng. (IJCCE), 28: 81-89 (2009).
[9] Sirousazar M., Kokabi M., Hassan Z.M., In Vivo and Cytotoxic Assays of a Poly(vinyl alcohol)/Clay Nanocomposite Hydrogel Wound Dressing, J. Biomater. Sci., Polym. Ed., 22: 1023-1033 (2011).
[10] Tajeddin B., Ramedani N., Preparation and Characterization (Mechanical and Water Absorption Properties) of CMC/PVA/Clay Nanocomposite Films, Iran. J. Chem. Chem. Eng. (IJCCE), 35: 9-15 (2016).
[11] Abdurrahmanoglu S., Can V., Okay O., Equilibrium Swelling Behavior and Elastic Properties of Polymer–Clay Nanocomposite Hydrogels, J. Appl. Polym. Sci., 109: 3714-3724 (2008).
[12] Can V., Abdurrahmanoglu S., Okay O., Unusual Swelling Behavior of Polymer-Clay Nanocomposite Hydrogels, Polymer, 48: 5016-5023 (2007).
]14[ سیروس آذر، محمد؛ کوکبی، مهرداد؛ حسن، زهیر محمد، بررسی خواص مکانیکی هیدروژل­های نانوکامپوزیتی پلی وینیل الکل، مجله علوم و تکنولوژی پلیمر، 17: 273 تا 280 (1383).
[15] Sirousazar M., Kokabi M., Hassan Z.M., Bahramian A.R., Mineral Kaolinite Clay for Preparation of Nanocomposite Hydrogels, J. Appl. Polym. Sci., 125: E122-E130 (2012).
[16] بشارتی سیدانی، عباس؛ غلامی، محمدرضا، تخریب فوتوکاتالیستی یک نمونه رنگ آزو به کمک نانوکامپوزیت­های بر پایه TiO2 اصلاح شده با فلزهای Pt، Pd و Ni، نشریه شیمی و مهندسی شیمی ایران، 34:39 تا 49 (1394).
[17] Sirousazar M., Kokabi M., Hassan Z.M., Swelling Behaviour and Structural Characteristics of Polyvinyl Alcohol/Montmorillonite Nanocomposite Hydrogels, J. Appl. Polym. Sci., 123: 50-58 (2012).
[19] Pooresmaeil M., Mansoori Y., Mirzaeinejad M., Khodayari A., Efficient Removal of Methylene Blue by Novel Magnetic Hydrogel Nanocomposites of Poly(acrylic Acid), Adv. Polym. Tech., DOI:10.1002/adv.21665 (2016).
[20] Li P., Siddaramaiah, Kim N.H., Yoo G.H., Lee J.H., Poly(acrylamide/laponite) Nanocomposite Hydrogels: Swelling and Cationic Dye Adsorption Properties, J. Appl. Polym. Sci., 111: 1786-1798 (2009).
[21] Sirousazar M., Kokabi M., Hassan Z.M., Bahramian A.R., Polyvinyl Alcohol /Na-Montmorillonite Nanocomposite Hydrogels Prepared by Freezing-Thawing Method: Structural, Mechanical, Thermal and Swelling Properties, J. Macromol. Sci. Part B Phys., 51: 1335-1350 (2012).
[22] Sirousazar M., Kokabi M., Hassan Z.M., Bahramian A.R., Dehydration Kinetics of Polyvinyl Alcohol Nanocomposite Hydrogels Containing Na-Montmorillonite Nanoclay, Sci. Iran. Trans. F: Nanotech., 18: 780-784 (2011).