COPOLYMERIZATION OF CARBON-MONOXIDE WITH PHENYLACETYLENE BY PALLADIUMCOMPLEX

Carbon monoxide was copolymerized with phenylacetylene (PA) using init iation by a palladium complex [Pd (CH3CN)(4)] (BF4)(2) under various c onditions. Good yields were obtained at 90 degrees C in methanol. Elem entary analysis, infrared and NMR spectroscopy showed that the copolym ers contained ketone and olefinic structures. 2,2'-bipyridine was a mo re effective stabilizing ligand than monodentate phosphorus, arsenic o r nitrogen ligands. The copolymer yield, molar mass and trans configur ation of the vinylene increased with increasing temperature. Methanol and the protonic acid served as coinitiator and chain-transfer agents. The copolymers have increasingly higher trans vinylene structure with the increase of pressure of carbon monoxide. X-ray diffraction analys is shows the copolymer to be partially crystalline. Thermogravimetric analysis showed that the copolymer started to lose mass at 213 degrees C and that maximum decomposition occurred at 390 degrees C. The PA/CO copolymer obtained under the influence of various ligands has a glass transition temperature (T-g) in the range 75-130 degrees C. Hydrogena tion of PA/CO copolymer with a reducing agent yielded a hydroxy-contai ning polymer.