International audienceThe "immortal" coordination-insertion ring-opening polymerization of benzyl malolactonate (MLABe) initiated by the two-component catalyst system based on the zinc amide precursor, (BDI)Zn[N(SiMe3)2] (BDI = β-diiminate ligand), and benzyl alcohol (BnOH) acting as a co-initiator and a chain transfer agent proceeds in bulk at 40 °C. Functional telechelic poly(β-benzyl malolactonate)s, H-PMLABe-OBn, are thus obtained. Sequential copolymerization with trimethylene carbonate (TMC) affords block copolymers, PTMC-b-PMLABe, which are alternatively prepared from the chemical coupling of the PMLABe-COOH and PTMC-OH homopolymers. Simultaneous copolymerization of both the lactone and the carbonate monomers offers the PTMC-co-PMLABe random copolymers. The (co)polymers have been characterized by NMR, FT-IR, SEC and DSC analyses. These represent the first examples of β-benzyl malolactonate/carbonate copolymers. More importantly, these (co)polymers could be synthesized free of metallic residues thereby making them suitable as biomedical and pharmaceutical biomaterials

The complexation and sustained release of dsRNA from highly branched polymers prepared via RAFT polymerisation and copolymerisation of the monomers DMAEA, DMAPA, and DMAEMA, is reported.