Ring-opening copolymerization of CHO and MA catalyzed by the asymmetrical Cr(III)-bis-Schiff-base complex

Using an asymmetrical Cr(III)-bis-Schiff-base complex [Cr(L)Cl] (1; H2L obtained from condensation of 5-bromo-salicylaldehyde and HL0 ((Z)-4-((2-aminophenylimino)(phenyl)methyl)-3-methyl-1H-pyrazol-5(4H)-one) as the catalyst, bulk solvent-free ring-opening copolymerization of CHO (cyclohexene oxide) and MA (maleic anhydride) in the presence of cocatalyst DMAP (4-(dimethylamino)-pyridine) was effectively realized, in which, on the condition of low 1/DMAP concentration for a controllable polymerization, perfectly alternating polyester while not poly(ester-co-ether) could be obtained. (C) 2017 Elsevier B.V. All rights reserved.