Structural characterization of hydroxyl terminated polyepichlorohydrin obtained using boron trifluoride etherate and stannic chloride as initiators

Epichlorohydrin was polymerized using boron trifluoride etherate or stannic chloride as initiators in presence of diols. The molecular weight of the polymer increased with increase in the ratio of epichlorohydrin to the diol in the reaction mixture. The polymers were characterized by IR, proton NMR and 13C NMR analysis. The terminal hydroxyl groups of the polymers were characterized by derivatizing them using trifluoro acetic anhydride and analyzing the resulting ester by NMR. Both primary and secondary hydroxyls were present in the polymer. The primary hydroxyl terminals of the polyepichlorohydrin (PECH) prepared using stannic chloride initiator were twice the amount of that present in the polymer prepared using BF3 etherate initiator. The 13C NMR spectrum of PECH prepared using BF3 etherate indicates that the polymer backbone is rich in H–T diad. Both cationic and co-ordination mechanisms operate during the polymerization in the presence of SnCl4 and the 13C NMR spectrum of the polymer showed more of T–T and H–H sequences.