Influence of the operating conditions on the catalytic activity of [PdCl2(dapp)] in the CO–ethene copolymerization in the H2O–CH3COOH as a solvent (dapp = 1,3-bis(di(2-methoxyphenyl)phosphino)propane)

The influence on the productivity of [PdCl2(dapp)] in H2O–CH3COOH in the CO–ethene copolymerization and on the LVN of the copolymer of the following reaction parameters has been studied: (i) composition of the H2O–CH3COOH reaction medium; (ii) temperature; (iii) CO/ethene ratio at a given total pressure; (iv) total pressure at fixed ratio CO/ethene = 1/1; (v) CO or ethene partial pressure at a given pressure of one monomer; (vi) reaction time. High molecular weight PKs are obtained under high pressure with the monomers in the ratio 1/1 at relatively low temperature and with a H2O/CH3COOH 40–50% with productivity ranging from 4 to 20 kg PK(g Pd h)−1.The relation between productivity and LVN has been discussed in the light of the key steps of the catalytic cycle.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (29 K)Download as PowerPoint slideResearch highlights▶ [PdCl2(dapp)] catalyzes the CO–ethene copolymerization in H2O–AcOH as a solvent. ▶ At 90 °C, 110 atm (CO/E 1/1), H2O 55%, 22,800 g PK(g Pd h)−1 are achieved, LVN 3.8 dL/g. ▶ At 60 °C 2500 g PK(g Pd h)−1 are produced with a much higher LVN (11.2 dL/g). ▶ At 75 °C both productivity and LVN are relatively high, 15,000 g PK(g Pd h)−1, 7 dL/g.