Influence of the reaction conditions on the productivity and on the molecular weight of the polyketone obtained by the CO-ethene copolymerisation catalysed by [Pd(TsO)(H2O)(dppp)](TsO) in MeOH

The influence of the operating conditions on the productivity on the CO-ethene copolymerisation catalysed by the title complex used in combination with TsOH and on the average numerical molecular weight, the limiting viscosity number and the average viscosity molecular weight of the resulting polyketone has been studied. The productivity, LVN and (M) over bar (v) pass through a maximum for a TsOH/Pd ratio= 6/1, whereas (M) over bar (n) reaches a plateau and remains practically constant at higher acid concentration. They increase upon increasing the pressures of the monomers when employed in the ratio 1/1 as well as upon increasing the pressure of CO keeping constant the pressure of the other monomer; the productivity as well as (M) over bar (n) increase, whereas the LVN and (M) over bar (v) pass through a maximum upon increasing the pressure of ethene, keeping constant the pressure of CO. A power law rate equation for the productivity has been obtained. The productivity decreases whereas the molecular weights increase upon lowering the temperature; the productivity decreases upon increasing the reaction time, whereas the molecular weights are little influenced. The results are discussed in the light of the copolymerisation mechanism. (C) 2007 Elsevier B.V. All rights reserved.