Acid-activated bentonite (Maghnite-H$^+$) as a novel catalyst for the polymerization of decamethylcyclopentasiloxane

Bulletin of Materials Science

MOHAMMED BELBACHIR^1¹  SAAD LAMOURI^3²  DJAMAL EDDINE KHERROUB^1,2³ 

[1] Institute of Sciences and Technology, University Centre of Relizane Ahmed Zabana, BP 48000, Relizane, Algeria^2;Laboratory of Macromolecular Chemistry, Polytechnic Military School (EMP), 16111 Bordj El Bahri, Algiers, Algeria^3;Laboratory of Polymer Chemistry, Department of Chemistry, Faculty of Exact and Applied Sciences, University of Oran, 1 Ahmed Ben Bella, BP 1524, 31000 El’Menouer Oran, Algeria^1

关键词: Catalyst;    maghnite-H$^+$;    bentonite;    decamethylcyclopentasiloxane;    ring opening polymerization.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

In this study, we propose Maghnite-H$^+$, as an ecological, cost-effective and easily renewable catalyst, for the polymerization of decamethylcyclopentasiloxane (D5). The Maghnite is a clay consisting primarily of smectite minerals (montmorillonite group), which can be activated/reactivated through a simple process, by replacing interlayer cations by protons. Linear polymers with higher molecular mass and narrower molecular mass distribution (MMD) can be obtained with less cyclic by-products, using Maghnite-H$^+$. The reaction was investigated in bulk, taking into account the effect oftime, temperature and amount of catalyst on the monomer conversion and MMD.When the yield rises to 96%, the MMD is broadened, suggesting the formation of cyclic oligomers and/or crosslinking bonds, this was confirmed experimentally by infra-red spectroscopy, proton nuclear magnetic resonance (${}^1$H NMR) and ${}^{13}$C NMR analyses. The kinetics have been also studied; the reaction is first order in the monomer. The proposed reaction mechanism shows clearly the role of Maghnite-H$^+$ for D5 polymerization.

【 授权许可】

CC BY