Synthesis, characterization, and some properties of 4-vinylpyridine-Cr(CO)5 containing polymers

The polymerization of 4-vinylpyridine (4VP) and 4-vinylpyridine chromium pentacarbonyl [(4VP) Cr(CO)(5)] was performed under N-2 atmosphere at 60 - 80 degreesC temperature range. Different percent of feed (% PF) of Cr( CO)(5) groups were anchored into poly(4-vinylpyridine) (P4VP) by addition of the intermediate Cr(CO)(5)THF, which was generated photochemically from Cr(CO)(6) in THF, to the polymer at ambient temperature. The determined percent of anchoring (% PA) has shown that the maximum anchored Cr(CO)(5) groups was 40% (w/w) with respect to P4VP, and the optimum percent of anchoring was 20% (w/w). The rate of polymerization (R-p) and the activation energy (E-a) of 4VP in the absence and in the presence of 16.7% Cr(CO)(5)(4VP) were determined. Thermal analysis has shown various changes in the properties of the 4VP polymers after modification of the polymer by Cr(CO)(5) groups. The X-ray diffraction and the melting enthalpy derived from the DSC thermogram revealed that the synthesized poly[(CO)(5)Cr(4VP)] has a crystallinity of about 40%, whereas no crystallinity was observed for pure P4VP.