Maghnite", a montmorillonite sheet silicate clay, exchanged with protons to produce "H-Maghnite" is an efficient catalyst for cationic polymerisation of many heterocyclic and vinylic monomers (Belbachir, M. U. S. Patent. 066969.0101-2001). The structural compositions of both "Maghnite" and "H-Maghnite" have already been determined. Epichlorhydrin monomer, which is polymerizable by a cationic process (Odian, G. La Polymerisation: Principes et Applications; Ed. Technica: New York, 1994; pp 222-226), was used to elucidate the polymerization cationic character. The polymerization was performed under optimum conditions at 20 degreesC. Experiments revealed that the polymerisation induced by "H-Maghnite" proceeds in bulk. In bulk polymerization, Epichlorhydrin conversion increases with increasing "H-Maghnite" concentration and temperature.