Anionic ring-opening polymerization cyclic carbonate

Among the more common thermoplastics from ring opening polymerization of interest in composite processing are polylactams, polyethers, polyacetals, and polycycloolefins. It has also been shown that polycarbonates can be produced from cyclic carbonates [22], Anionic ring opening polymerization of caprolactam to nylon 6 is uniquely suited to form a thermoplastic matrix for fiber-reinforced composites, specifically by the reaction injection pultrusion process [23-25]. The fast reaction kinetics with no by-products and the crystalline... 

Haba O., Tomizuka H., Endo T, Anionic ring-opening polymerization of methyl 4,6-0-benzylidene-2,3-0-carbonyl-a-D-glucopyranoside A first example of anionic ring-opening polymerisation of five-membered cyclic carbonate without elimination of CO2, Macromolecules, 38, 2005, 3562-3563. 

Murayama, M., Sanda, F., Endo, T., 1998. Anionic ring-opening polymerization of a cyclic carbonate having a norbomene stmcture with amine initiators. Macromolecules 31, 919-923. 

Aliphatic polysulfides with two or more carbon atoms per monomeric unit are accessible through ring opening polymerization of cyclic sulfides or by the addition of thiol groups onto vinyl groups. In these cases, the anionic polymerization of cyclic sulHdes differs substantially from that of cyclic ethers. The ethyl anion attacks the carbon atom in cyclic ethers. But in the ethyl lithium initiated polymerization of propylene sulfide, a lithium ethane thiolate is first formed, and its anion then starts the polymerization of propylene sulfide ... 

There are a number of heterocyclic monomers, for example, epoxides, cyclic sulfides, lactones and lactides, lactams, cyclic carbonates, and cydosUoxanes, which can be polymerized by ring-opening reactions many of them can he polymerized by an anionic as well as by a cationic mechanism. They cannot all be covered here, but there are a number of monographs and reviews on this subject [181-185]. 

The lack of polyethylene samples with tailored architectures, controlled molecular weight, low PDI, and absence of branching defects has hmited a systematic study of the relationships between molecular structure and physical properties of polyethylene. Several notable exceptions include cyclic polyethylene that has been synthesized by ring-opening metathesis polymerization (ROMP) (PDI of 2) (Bielawski et al., 2002 Bielawski et al., 2003) and star, comb, H-shape and pom-pom polyethylenes, containing 17—25 ethyl branching defects per 1000 carbons, which were produced by anionic polymerization (Hadjichristidis et al., 2000). 

Bifunctional cycUc carbonates consisting of both five-and six-membered rings were selectively polymerized by means of anionic ROP using DBU as inihator to afford a Unear polycarbonate with five-membered cyclic carbonate groups in the side chain. This result provides experimental proof of the thermodynamic stability of the five-membered cycUc carbonate, and the thermodynamic instability of the six-membered cycUc carbonate. Further functionalization of these polymers by means of functional amines, which react with the cyclic carbonate groups but not with the linear open-chain carbonate groups, was performed to result in multifunctional polycarbonates [82]. 

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