Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+

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.

Green Polymerization of Hexadecamethylcyclooctasiloxane Using an Algerian Proton Exchanged Clay Called Maghnite-H+

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

Catalytic Activity of Maghnite-H+ in the Synthesis of Polyphenylmethylsiloxane under Mild and Solvent-free Conditions

In this study, a new and easy strategy was discussed for the purpose of synthesizing of a polymer of phenylmethylcyclosiloxane type (PPMS). The cationic ring opening polymerization of triphenyltrimethylcyclotrisiloxane (D3Ph,Me) was initiated by a solid, efficient and environmentally-friendly catalyst called Maghnite-H+. Maghnite-H+ is a natural clay composed essentially of montmorillonite, it is activated with an acid treatment by replacing the interlayer ions by protons, that results to the increase of the basal space, this may be confirmed by XRD analysis. The reaction was carried out without solvent at different temperatures and for different periods of time, using also several catalyst contents. Subsequently, the operating conditions were opted in order to obtain a maximum yield of the linear polymer and a high average molecular mass as well. The structure of polymers obtained was confirmed by IR analysis. 1H NMR and 13C NMR analyzes were used to follow the crosslinking of polymer chains over time. The thermal behavior was investigated by DSC analysis. The average molecular mass and the polydispersity indices were determined by GPC

Highly Conductive and Soluble Polymer Synthesized by Copolymerization of Thiophene with Para-Methoxybenzaldehyde Using Clay Catalyst

This present research focuses on the synthesis of a new conducting polymer based on the copolymerization of thiophene with para-methoxybenzaldehyde, using a clay as an ecologic catalyst named Maghnite-H+. The catalysis of the reaction by Maghnite-H+ can confer it important benefits, such as the green environment aspect. The reaction was carried out in dichloromethane as a solvent. The new copolymer obtained is a poly (heteroarylene methines) small bandgap polymers precursor. It can be considered as a useful model system for examining the impacts of π-conjugation length on the electronic properties of this type of conjugated polymers. The measurements of the electrical conductivity gave a value of order of 0.0120 W.cm-1, allowing its use in various important applications. The characteristics of the molecular structure and the thermal behavior of the conducting polymer obtained are also discussed using different methods of analysis, such as: proton nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, ultraviolet/visible spectroscopy, and thermal gravimetric analysis (TGA). Copyright © 2019 BCREC Group. All rights reserve

Green synthesis, anionic polymerization of 1,4-bis(methacryloyl)piperazine using Algerian clay as catalyst

In this work, a chain of reactions has been proposed as a new heterogeneous technique, based on the use of natural treated clays as an environmentally friendly catalysts for the synthesis of poly(1,4-bis(methacryloyl)piperazine). We first synthesized the monomer; 1,4-bis(methacryloyl)piperazine (NBMP) in bulk (without solvent) by the condensation of heterocyclic secondary amines piperazine with methacrylic anhydride catalyzed by maghnite-H+ at room temperature during 2 h. After that, we have polymerized anionically the obtained NBMP in an ice bath using anionic catalyst maghnite-Na+ at 0°C, the reaction took place in 24 h. The poly(1,4-bis(methacryloyl)piperazine) and NBMP structure was characterized and confirmed by infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopies. Thermal properties of the polymer were determined using thermogravimetric analysis. The yield of the reaction was 72% and 59% for the monomer and polymer synthesis respectively. The effect of the weight content of the catalyst on the reaction yield was studied. A polymerization mechanism has been suggested showing the role of maghnite as a catalyst during the reaction courses

Cationic Ring Opening polymerization of ε-caprolactam by a Montmorillonite Clay Catalyst

<p>The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H+ was reported. Maghnite-H+ is a montmorillonite silicate sheet clay was prepared through a straight forward proton exchange process. The effect of the amount of catalyst, and temperature was studied. Increasing Maghnite-H+ proportion and temperature produced the increase in ε-caprolactam conversion. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer inserted into the growing chains with the acyl–oxygen bond scission rather than the break of alkyl–oxygen bond. © 2014 BCREC UNDIP. All rights reserved</p><p><em>Submitted: 3rd October 2013; Revised: 28th February 2014; Accepted: 1st March 2014</em></p><p>[<strong>How to Cit</strong>e: Kherroub, D.E., Belbachir, M., Lamouri, S. (2014). Cationic Ring Opening Polymeriza-tion of ε-caprolactam by a Montmorillonite Clay Catalyst. <em><strong>Bulletin of Chemical Reaction Engineering &amp; Catalysis</strong></em>, 9 (1): 74-79. (doi:10.9767/bcrec.9.1.5555.74-80)]</p><p><br />[<strong>Permalink/DOI</strong>: <a href="http://dx.doi.org/10.9767/bcrec.9.1.5555.74-80">http://dx.doi.org/10.9767/bcrec.9.1.5555.74-80</a>]</p><p><em><br /></em></p

Mechanical analysis of powdered activated carbon-filled polyurethane foam composites for oil spill cleanup

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