Lanthanum Tris(2,6-di-tert-butyl-4-methylphenolate) as a Novel, Versatile Initiator for Homo- and Copolymerization of Cyclic Carbonates and Lactones

Lanthanum tris(2,6-di-tert-butyl-4-methylphenolate) is reported as a highly active initiator for homopolymerizations of DTC, TMC, and CL as well as random copolymerizations of DTC with CL and with TMC, respectively. The monomer insertion occurs via acyl-oxygen bond cleavage. The random structures of copolymers are identified by GPC, 1H NMR, and DSC. The reactivity ratios of DTC and CL are measured to be 13.4 (rDTC) and 0.20 (rCL), respectively.