Abstract: A novel complex composed of chitosan(CS) and neodymium(Nd) was preparedand the ring opening polymerization of epichlorohydrin(ECH) with a new catalyticsystem comprising this new rare earth polymer complex(CS·Nd) has been suc-cessfully carried out for the first time.It has been found that the new catalytic sys-tem composed of CS·Nd-AI (i-Bu)₃-methyl benzoxylate( Ⅲ) is an excellent cata-lyst for the polymerization of epichlorohydrin which shows a catalytic activity 60 times higher tlian that of conventional rare earth catalyst.Under the following re-action conditions: Nd=1 ×10^-6 mo1/g monomer, A1/Nd= 60 molar ratio, Ⅲ/A1=0.6 molar ratio, the monomer conversion and PECH molecular weight are as highas 92.9% and 28.2 × 10⁵ respectively and the polymer prepared has a low crys-tallinity.The kinetics investigation revealed that the polymerization has a short in-duction period of several minutes and the rate of polymerization is of first orderwith respect to the monomer concentration and the catalyst concentration.The acti-vation energy of the polymerization reaction was found to be 25.5 kJ/mol which islower than that of conimon rare earth catalvst.

Key words: Neodymium cliitosan complex, Epichlorohydrin, Ring opening poly-merlzation