High-molecular-weight polyketones from higher α-olefins: A general method

A method to optimize the polymerization conditions in order to favor chain propagation is described for the synthesis of polymers containing low reactive, long, linear 1 - olefins and carbon monoxide (CO). It consists of the use of the olefin monomer as the polymerization solvent, together with the emulsification of a carefully chosen immiscible activator. This is given as a general method applicable to different families of catalyst able to produce 1,4-polyketones. When the catalyst precursor is [dpppPd(NCCH₃)₂](BF ₄)₂, which has been extensively studied, the polymerization degrees are the highest published (up to 2.4 × 10 ⁵ g · mol^-1). The influence of parameters like temperature, CO pressure, volume of activator, and catalyst counter ion or ligand substitutions are reported. Some chemical and physical properties of the polymers, such as glass transition temperature, melting processes, and mechanical behavior, are examined and compared with the linear 1-olefin homologues from C3 to C10. These properties are shown in some cases to be unprecedented.