Acyclic diene metathesis polyethylenes

Keywords Acyclic diene metathesis polymerization, ADMET, Condensation polymerization Functionalized polymers, Negative neighboring group effect, Branched polyethylene... 

Also, a series of well-defined polyolefins, including perfectly branched polyethylene and ethylene/a-olefin copolymers, have been synthesised via acyclic diene metathesis polycondensation [scheme (28)] [47] these well-defined polyolefins have been designed to model the crystallisation of polyethylene and olefin copolymers. 

Olefin metathesis (OM) has proven to be one of the most important advances in catalysis in recent years based on the application of this chemistry to the synthesis of polymers and biologically relevant molecules [1-10]. This unique transformation promotes chain and condensation polymerizations, namely ring opening metathesis polymerization and acyclic diene metathesis polymerization (ADMET). Applications of metathesis polymerization span many aspects of materials synthesis from cell-adhesion materials [11] to the synthesis of linear polyethylene with precisely spaced branches [12]. 

O Gara JE, Wagener KB, Hahn SF (1993) Acyclic Diene Metathesis (ADMET) Polymerization. Synthesis of Perfectly Einear Polyethylene. Makromol Chem Rapid Commun 14 657-662. 

Smith JA, Brzezinska KR, Valenti DJ, Wagener KB (2000) Precisely Controlled Methyl Branching in Polyethylene via Acyclic Diene Metathesis (ADMET) Polymerization. Macromolecules 33 3781-3784. 

Smith, J.A., Brzezinska, K.R., Valenti, D.J. and Wagener, K.B. (2000) Precisely controlled methyl branching in polyethylene via acyclic diene metathesis (ADMET) polymerization. Macromolecules 33, 3781-3794. 

O Gaia, J.E., Wagener, K.B., Acyclic diene metathesis (Admet) polymerization - synthesis of perfectly linear polyethylene, Makromol. Chem. Rapid Commun. 1993,14 657-662. 

Apart from cross-metathesis, ROMP, and RCM, there are other less common metathesis reactions. These are acyclic diene metathesis polymerization (ADMET), ring-opening cross-metathesis (ROCM), ring-rearrangement metathesis (RRM), and ethenolysis. A general ADMET reaction is shown by reaction 7.3.1.7. ADMET reactions are generally performed on a,well-defined and strictly linear polymers with unsaturated polyethylene backbones. Ethenolysis is the cross-metathesis of ethylene with an internal olefin. 

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