Ring-opening polymerization of cyclic monomers

Ring-opening polymerization of cyclic monomers, usually by anionic or cationic catalysts, is another route to elastomers. These include the polymerization of octamethylcyclotetrasiloxane... 

Lipase-Catalyzed Ring-Opening Polymerization of Cyclic Monomers... 

The ring-opening polymerizations of cyclic monomers such as propylene oxide... 

The ring opening polymerization of cyclic monomers that yield thermoplastic polymers of interest in composite processing is reviewed. In addition, the chemistry, kinetics, and rheology of the ring opening polymerization of caprolactam to nylon 6 are presented. Finally, the rheo-kinetics modelsfor polycaprolactam are applied to the composite process of reaction injection pultrusion. 

Ring opening polymerization of cyclic monomers to yield thermoplastic polymers has been studied by a number of investigators [1-19] over the years. A variety of cyclic monomers ranging in structures from the more commonly encountered olefins, ethers, formals, lactones,... 

Polycarbonates, both aliphatic and aromatic, have been prepared by the ring opening polymerization of cyclic monomers or oligomers [22], Cyclic monomeric precursors are more common in aliphatic polycarbonates, but because of steric reasons aromatic polycarbonates can only be prepared from cyclic oligomers. Both cationic and anionic initiators have been examined and anionic initiators appear to be more efficient. 

The ring-opening polymerization of cyclic monomers can be performed by ionic chain polymerization, as is the case of epoxy monomers. Anionic polymerization of ethylene oxide propylene oxide, and caprolactone can be initiated by alkoxides ... 

In addition to step and chain polymerizations, another mode of polymerization is of importance. This is the ring-opening polymerization of cyclic monomers such as cyclic ethers, esters (lactones), amides (lactams), and siloxanes. Examples of commercially important types are given in Table 10.1. Of those listed, only the polyalkenes are composed solely of carbon chains. Those that have enjoyed the longest history of commercial exploitation are polyethers prepared from three-membered ring cyclic ethers (epoxides), polyamides from cyclic amides (lactams), and polysiloxanes from cyclic siloxanes. 

With the development of polymer science and synthesis of newer polymers, this definition of condensation polymer was found to be inadequate. For example, in polyurethanes, which are classified as condensation polymers, the repeat unit has the same net composition as the two monomers-that is, a diol and a diisocyanate, which react without the elimination of any small molecule. Similarly the polymers produced by the ring-opening polymerization of cyclic monomers, such as cyclic ethers and amides, are generally classified as condensation polymers based on the presence of fimctional groups, such as the ether and amide linkages, in the polymer chains, even though the polymerization occurs without elimination of any small molecule. 

Ring-Opening polymerization of cyclic monomers, succinic anhydride and telrahydrofuran, can also be applied for PHB synthesis. Catalyzed by aluminum inflate at 100°C for 48 h, PBS with of 12,400 was obtained at a yield of 49% (Wang and Kunioka 2005). 

Wan C, Li Y, Shahbazi A, Xiu S (2008) Succinic acid production from cheese whey using ActinobacUlus succinogenes 130 Z. Appl Biochem Biotechnol 145 111-119 Wang Y, Kunioka M (2005) Ring-opening polymerization of cyclic monomers with aluminum triflate. Macromol Symp 224 193-205... 

Ring-opening polymerization of cyclic monomers is initiated either thermally or anionically. Reactive monomers are obtained from (C6H5)8Si4 via de-phenylation with HCl or TfOH (see Figs. 5 and 6) and subsequent substitution... 

The smallest ring of a cyclic acetal contains five atoms. Ring-opening polymerization of cyclic monomers with rings composed of more than four atoms is a reversible process due to a relatively low negative AHp (enthalpy of polymerization) value (Table 1) [see Chapter 4.02). Thus, monomer-polymer equilibrium is established, and if the equilibrium monomer concentration [M]e is higher than its starting concentration, polymerization is not possible. This is the case with the six-membered cyclic acetal 1,3-dioxane. 

Olivier Coulembier received his PhD degree from the University of Mons-Hainaut (Belgium) in 2005 and Joined the University of Stanford (United States) for his postdoctoral research in 2006. He is currently a research associate by Belgian FNRS in the Laboratory of Polymeric and Composite Materials (LPCM) of Professor Philippe Dubois at the University of Mons. His main activities are focused on the (non)oiganometallic ring-opening polymerization of cyclic monomers. He has (co)authored 50 scientific papeis in international journals, 1 patent, and 1 book chapter. 

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