Coordinate polymerization of heterocycles: 1. Oligomerization of epichlorohydrin by TiCl4

The polymerization of epichlorohydrin proceeds via the TiCl₄. 2EPC complex provided the concentration of epichlorohydrin is twice as high as that of TiCl₄. The oligomerization process requires supposedly the existence of a complex in which the epichlorohydrin is coordinate through a ClTi bond. Diethyl ether has an inhibiting effect on the reaction. The oligomerization rate is increased in the presence of acetyl chloride, diethyl ether having no effect this time. The transformation of epichlorohydrin to polymer is always kinetically non-stationary, the number of active centres decreasing with time. Both the initiation and propagation steps proceed through a rearrangement following the coordination of monomer to the activating ligands. No polymerization active free ions have been found to be present in the system. The intermediate and final products were analysed employing spectral, chromatographic, kinetic, and conductivity measurements. The reaction mechanism of oligomerization has been suggested.