The purpose of this study was to synthesize polydimethylsiloxanes by heterogeneous catalysis, based on the polymerization of the hexadecamethylcyclooctasiloxane (D8) by an environment-friendly solid catalyst (Maghnite-H+). Maghnite-H+ is a natural Algerian clay of the montmorillonite type, prepared by activation with sulfuric acid, the impact of this activation was observable in the XRD spectrum, by the increase in the interlayer spacing (d001) resulting from the intercalation of hydronium ions between layers. The molecular structure of the obtained polymer was determined by different chemical methods of analysis such as IR, 1H NMR, and 13C NMR. The thermal behavior of the polysiloxane obtained was confirmed by DSC. In order to achieve the best possible yield and at the same time to get a polymer of high molecular mass, the operating conditions have been set at t = 8 h and T = 70 °C after the reaction was repeated several times. The average molecular mass and the polydispersity index were measured by GPC. A reaction mechanism has been suggested to show the action of the Maghnite-H+ during the reaction. Copyright © 2018 BCREC Group. All rights reserved Received: 8th March 2017; Revised: 27th July 2017; Accepted: 1st August 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Kherroub, D.E., Belbachir, M., Lamouri, S. (2018). Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 36-46 (doi:10.9767/bcrec.13.1.993.36-46)