Pd(II)-catalyzed emulsion copolymerization of carbon monoxide with ethene in CH2Cl2/water as a solvent

Chemical, physical and mechanical characteristics of alt poly(1-oxo-trimethylene) [1] well fit with a wide range of industrial applications and recently several researchers have shown a renovated keen interest for the application of such a polymer in the field of fibers [2]. In order to obtain fibers, however, high molecular weight polymers are required. In some papers we have reported that high molecular weight polymers require high pressure and low temperature but the nature of the solvent must be considered too [2-4]. The choose of the solvent influences both the activity of the catalyst and the average molecular weight of the polymer. Usually the catalysis is efficiently carried out in methanol by using the [Pd(OAc)2(DPPP)] complex in the presence of an acid (p-toluenesulfonic, TsOH) [5] which leads to polymers with not so high average molecular weight. By replacing methanol with CH3COOH-water also [PdCl2(DPPP)] complex efficiently catalyzes the reaction leading also to an increase of the polymer molecular weight [3]. By continuing the research on the influence of the solvent on the molecular weight, here we report our preliminary results on the preparation of alt- poly(1-oxo-trimethylene) by emulsion catalytic polymerization. The [PdCl2(DPPP)] complex has been dissolved in a CH2Cl2-H2O emulsion and the productivity has been optimized.