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论文类型：期刊论文

发表时间：2010-02-09

发表刊物：MACROMOLECULES

收录刊物：SCIE、EI

卷号：43

期号：3

页面范围：1396-1402

ISSN号：0024-9297

摘要：The cobalt(III) complex of a salen ligand bearing one quaternary ammonium salt on the three-position of one aromatic ring is a highly active catalyst for the alternating copolymerization of cyclohexene oxide (CHO) and CO2 to afford the corresponding poly(cyclohexene carbonate) (PCHC) at various temperatures. The cobalt-based catalyst exhibited excellent activity and selectivity for polymer formation at high temperatures up to 120 degrees C and even under low CO2 pressures of 0.1 MPa. Also, the cobalt(III)-salen complex could operate very efficiently for the terpolymerization of CHO and aliphatic epoxides with CO2 to provide selectively polycarbonates with a narrow polydispersity at high temperatures. The polycarbonates resulting from the terpolymerization of equimolar CHO and propylene oxide (PO) with CO2 have a close content for both cyclohexene carbonate and propylene carbonate units. This is ascribed to the presence of CHO significantly inhibiting the reactivity of PO and thereby causing a matched reactivity for both epoxides during the terpolymerization. The competition coordination of CHO and PO to the electrophilic cobalt(III) ion has no effect on regioselective ring-opening of PO in the terpolymerization.