Study of cobalt(II)-chitosan coordination polymer and its catalytic activity and selectivity for vinyl monomer polymerization

A cobalt(II)-chitosan coordination polymer has been prepared by soaking a chitosan film in CoCl2 aqueous solution. The results have been investigated by means of X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared FT-IR spectroscopy, thermal analysis and electrical conductivity measurements. The XPS and FT-IR spectra reveal that the chitosan coordinated with cobalt(II) through both oxygen and nitrogen atoms in the chitosan chain. The XPS results show that the coordination polymer possess the same shake-up peaks with CoCl2, indicating that the cobalt(II)-chitosan coordination polymer is high spin and the coordination number of cobalt(II) centers is four, and the electrical conductivity measurements confirm this result. Also, cobalt(II) coordination polymer can be used as a catalyst, and the polymerization of vinyl acetate was carried out in the presence of the coordination polymer/Na2SO3/H2O at pH 7 and normal temperature. The polyvinyl acetate possessed a random structure. Copyright (C) 2004 John Wiley Sons, Ltd.