Abstract: A process for the preparation of copolymers of carbon monoxide with an olefinically unsaturated compound comprising copolymerizing the monomers in the presence of a catalyst composition based upon(a) a salt of a Group VIII metal, and(b) a cation which is selected from cationic oxidants and cations of the general formulae R.sub.n H.sub.4-n N.sup.+, R.sub.m H.sub.3-m C.sup.+ and R.sub.m H.sub.3-m O.sup.+, wherein n is 0, 1, 2, 3 or 4, m is 2 or 3, and R represents a hydrocarbyl group and/or two or three of R together with the atom carrying a positive charge represent a ring structure, on the understanding that when n is 3, at most two of R together with nitrogen represent a heterocyclic ring structure, and when n is 4, three of R together with nitrogen represent an aromatic heterocyclic ring structure.

Abstract: A process for the copolymerization of carbon monoxide with an olefinically unsaturated compound comprising contacting the monomers in the presence of a liquid diluent with a catalyst composition which is based on(a) a source of a Group VIII metal,(b) a bidentate ligand of the general formulaR.sup.1 R.sup.2 M.sup.1 --R--M.sup.2 R.sup.3 R.sup.4 wherein M.sup.1 and M.sup.2 independently represent a phosphorus, arsenic or antimony atom, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently represent unsubstituted or substituted hydrocarbyl groups on the understanding that at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 represents a polar substituted aryl group and R represents a bivalent bridging group containing at least two carbon atoms in the bridge, and(c) a boron hydrocarbyl compound,with application of a stirring power transmitted to the polymerization mixture of at least 0.25 kW/m.sup.3.

Abstract: A process for the copolymerization of carbon monoxide with an olefinically unsaturated compound in which a solid particulate material is suspended in a liquid diluent in which the polymer to be produced forms a suspension. The monomers are contracted in the liquid diluent containing the suspended solid particulate material with a catalyst composition which is based on a source of a Group VIII metal and a boron hydrocarbyl compound.

Abstract: A process for the copolymerization of carbon monoxide with an olefinically unsaturated compound in which the monomers are contacted in the presence of a liquid diluent and a protic compound with a catalyst composition which is based on a source of a Group VIII metal and a hydrocarbylborane. A stirring power is transmitted to the polymerization mixture of at least 0.25 kW/m.sup.3.

Abstract: A process for the copolymerization of carbon monoxide with an olefinically unsaturated in which the monomers are contacted with a catalyst composition which is based on a source of a Group VIII metal and a boron hydrocarbyl compound. Additional boron hydrocarbyl compound is added to the polymerization mixture during the copolymerization or when the catalyst has lost its activity. A process for recycling a polymerization catalyst is also presented. It includes the steps of recovering a Group VIII metal composition from a preceding copolymerization process for the preparation of a copolymer of carbon monoxide and an olefinicaIly unsaturated compound and adding a boron hydrocarbyl compound to the Group VIII metal composition.