| 主权项 |
1. A method comprising:
immortal ring-opening homopolymerisation of cyclic carbonates or cyclic esters in the presence of a catalytic system to form a homopolymer, or sequential two-step ring-opening block copolymerisation of cyclic monomers comprising cyclic carbonates and cyclic esters in the presence of the catalytic system to form a block copolymer comprising a polyester block and a polycarbonate block, wherein the catalytic system comprises:
a metallic complex of formula M(OAr)nXm; wherein M is Sn; wherein OAr is a phenolate ligand; wherein X is an alkyl having from 1 to 6 carbon atoms, an amido group, or an alkoxide group; and wherein n is at least 1 and n+m is the valence of M; andan alcohol ROH or a primary amine RNH2; wherein R is an hydrocarbyl group, linear or branched, having from 1to 20 carbon atoms, containing aliphatic and/or aromatic moieties; and wherein the alcohol or the primary amine is present in a molar ratio with respect to the metallic complex that is larger than 1; wherein the phenolate ligand is prepared from a phenol-based pro-ligand of formula wherein R1, R2 and R3 are the same or are different and are each a hydrogen or are selected from methyl, ethyl, iso-propyl, tert-butyl, neo-pentyl, cumyl, trityl, phenyl, 2,4,6-trimethylphenyl, 2,6-diisopropylphenyl. |
