High molecular weight 1-olefin/carbon monoxide copolymers: A new class of versatile polymers

The moderate electrophilicity of palladium(II)-phosphine catalysts compared to those of zirconocene dichlorides makes them more tolerant toward a variety of polar functionalities of olefinic monomers. This allows use of Pd(II) complexes as catalysts for the copolymerization of olefins with readily available polar monomers, like acrylic acid derivatives or carbon monoxide. In particular, developments during the recent years have opened the way to a new and broad family of high molecular weight 1-olefin/CO co- and terpolymers. These 1,4-polyketone materials show interesting and easily variable properties which can be tuned from insoluble, highly crystalline to thermoplastic elastic. The latter polymers resemble in some cases flexible PVC and even vulcanized natural rubbers.