Cobalt(III)‐complex‐mediated terpolymerization of CO2, styrene oxide, and epoxides with an electron‐donating group. Issue 4 (19th November 2012)

• Record Type: Journal Article
• Authors: Wu, Guang‐Peng; Xu, Peng‐Xiang; Zu, Yu‐Ping; Ren, Wei‐Min; Lu, Xiao‐Bing
• Is Part Of: Journal of polymer science. Volume 51:Issue 4(2013:Feb.)
• Page Start: 874
• Page End: 879
• Publication Date: 2012-11-19
• Subjects: carbon dioxide -- catalysts -- cobalt -- epoxide -- polycarbonates -- polymerization catalysis -- ring‐opening polymerization -- terpolymerization; 547
• DOI: 10.1002/pola.26444
• Languages: English
• ISSNs: 0887-624X

Abstract

Abstract: Terpolymerizations of CO2, styrene oxide (SO), and epoxides with an electron‐donating group such as propylene oxide (PO) or cyclohexene oxide (CHO) were carried out by using Co(III)–salen complexes in the presence of an intra‐ or intermolecular nucleophilic cocatalyst. The resultant terpolymers have only one thermolysis peak and one glass transition temperature ( T g ), which can be easily adjusted by controlling the proportion of styrene carbonate linkages. During the CO2 /SO/PO terpolymerization, the monomer reactivity ratios ( r SO = 0.18 and r PO = 2.25) evaluated by Fineman–Ross plot indicates a random distribution of the two kinds of carbonate units in the resultant polymer. Contrarily, the monomer reactivity ratios were found to be r SO = 0.48 and r CHO = 0.79 in the CO2 /SO/CHO terpolymerization, indicating that an alternating nature of the two different carbonate units predominantly exists in the resultant polycarbonate. The regioselective ring opening of SO has a significant effect on the reactivities of both SO and CHO during the terpolymerization with CO2 . The matched reactivity is contributed to the enhanced regioselective ring opening of SO, caused by the attack of the dissociating polymer carboxylate anion, bearing a cyclohexene carbonate end unit. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 Abstract : The terpolymerization of CO2, styrene oxide and epoxide, bearing an electron‐donating group has been achieved with the use of cobalt‐based complexes as catalyst at mild conditions. A random distribution of the two kinds of carbonate units is present in the CO2 /styrene oxide/propylene oxide terpolymer, whereas an alternating nature of the two different carbonate units predominantly exists in the CO2 /styrene oxide/CHO terpolymer.