Polymerization of ε-caprolactone using a montmorillonite clay as catalyst

Abstract

Abstract-In the present work the ring-opening polymerization of ε-caprolactone using a protonexchanged montmorillonite clay as initiator is reported. The influences of reaction temperature, solvent, weight ratio of initiator/monomer and reaction time on the conversion of monomer and the molecular weight are investigated. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer was inserted into the growing chains by acyl-oxygen bond scission rather than the break of alkyl-oxygen bond.

Synthesis and Characterization of a new hybrid material (MOF-5/Mag-H+ ) based on a Metal-Organic Framework and a Proton Exchanged Montmorillonite Clay (Maghnite-H+) as catalytic support

“…On all the spectra, two small bands can be distinguished at apparent chemical shifts of 58-60 ppm and 68-71 ppm and which are assigned to AlO 4 octaedric sites in the Maghnite structure as a consequence of isomorphic ions substitution within the silicate layers. Another dominant asymmetric line at apparent chemical shifts of 3-4 ppm is assigned to AlO 6 sites within the octahedral sheets of the clay [19][20][21][22]. All spectra are similar, indicating that the aluminosilicate layers of the clay are not chemically modified by their incorporation in MOF-5 during the polymerization process.…”

Preparation of vinyl chloride – vinyl ether copolymers via partial etherification from PVC

“…4. The preparation of Maghnite-K was carried out with the method described by Belbachir and coworkers [8][9][10][11], using 100 g of the raw Algerian clay (Maghnia; West Algeria) and 20 g of potassium hydroxide (KOH, Fisher Scientific). It was crushed for 20 min with a Prolabo ceramic balls grinder, then dried through baking at 105°C for 2 h and cooled to room temperature.…”

Maghnite, a Green Catalyst for Cationic Polymerization of Vinylic and Cyclic Monomers

“…[14] We propose in this article a new method of preparing methacryloyloxy-PDXL that is done in only one step. Indeed, to produce PDXL and methacryloyloxy-PDXL, we use Maghnite-H (Mag-H), a new nontoxic cationic initiator of heterocyclic monomers [15][16][17][18][19][20][21][22] and vinyl monomers. [23,24] Mag-H can be easily separated from the polymer and regenerated.…”