Ionic polymerization metathesis

Metathesis can be accomplished with mthenium-based catalysis in water solvent, whereas ionic processes typical in the ROP exclude water as a reaction medium (there are a few exceptions the most basic monomers, radical ROP as well as unusual ionic polymerization in water emulsions (cyclic siloxanes)). 

Ionic, Ziegler-Natta and Ring-Opening Metathesis Polymerization By V. Dragiitan and R. Streck... 

Langsdorf BL, Zhou X, Lonergan MC. Kinetic study of the ring-opening metathesis polymerization of ionically functionalized cyclooctatetraenes. Macromolecules 2001 34 2450-2458. 

Figure 7.4-2 Acyclic diene metathesis polymerization (ADMET) reaction carried out in the neutral ionic liquid [EMIMlCI/AICIj (X(AICl3) = 0.5) [52].

Most cyclic monomers of interest in the field of composites happen to be heterocyclic in nature. Polymerizability of some monomers is summarized in Table 1.1. Ring opening polymerizations invariably follow ionic mechanisms, although a few are known to proceed via the free radical route and some via metathesis involving metallocarbene intermediates. 

If the metathesis polymerization is performed in solution, the preferred solvents are methylene chloride or chlorobenzene. Preferably, the solvent is aprotic in order to avoid ionic side reactions. The molecular weight is controlled by the addition of an acyclic olefin, such as 1-butene (13). 

Acyclic carbenes, with palladium isocyanides, 8, 258 Acyclic diene metathesis polymerization alkynes, 1, 191 characteristics, 1, 138 in ionic liquids, 1, 869... 

Olefin isomerization, with Claisen rearrangement, 1, 365 Olefin metathesis with alkyllead, 9, 415 in aqueous media, 1, 834 ESI—MS studies, 1, 812 in high-throughput catalyst discovery, 1, 365 in ionic liquids, 1, 869 for polymerization characteristics, 1, 149 Grubbs catalysts, 1, 151 Schrock catalysis, 1, 150... 

Most polymerizations of cyclic monomers are ionic processes. Coordination catalysts are effective only for some heterocycles (oxirane and its derivatives, lactones). Ziegler-Natta catalysts can only be used for cycloalkene polymerization by metathesis heterocycles act as a catalytic poison. Smooth radical polymerization of hydrocarbon monomers with ring strain is unsuccessful [304], The deep-rooted faith that ring strain represents a major contribution to the driving force in ring opening (polymerization) has to be revised [305, 306]. 

Xie M, Han H, Ding L et al (2009) Promotion of atom transfer radical polymerization and ring-opening metathesis polymerization in ionic liquids. J Macromol Sci R, Part C Polym... 

The same acidic chloroaluminate ionic liquids have been used as solvent for tungsten aryl oxide complexes for the metathesis of alkenes [24]. Slightly acidic chloroaluminates also dissolve the [Cl2W=NPh(PMe3)3] complex which catalyze ethene oligomerization without the addition of co-catalysts [25]. In a similar way, Ni-catalyzed 1-butene dimerization into linear octenes was carried out in acidic chloroaluminates buffered with small amount of weak bases [26]. Neutral chloroaluminates (l-ethyl-3-methylimidazolium chloride/AlCl3 = 1) were employed to immobilize ruthenium carbene complexes for biphasic ADMET (acyclic diene metathesis) polymerization of an acyclic diene ester [27]. 

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