Radical polymerization of vinyl monomers

Noda and Watanabe [42] reported a simple synthetic procedure for the free radical polymerization of vinyl monomers to give conducting polymer electrolyte films. Direct polymerization in the ionic liquid gives transparent, mechanically strong and highly conductive polymer electrolyte films. This was the first time that ambient-temperature ionic liquids had been used as a medium for free radical polymerization of vinyl monomers. The ionic liquids [EMIM][BF4] and [BP][Bp4] (BP is N-butylpyridinium) were used with equimolar amounts of suitable monomers, and polymerization was initiated by prolonged heating (12 hours at 80 °C) with benzoyl... 

Active polymers from oligoperoxides. Active polymers can be obtained by the free radical polymerization of vinyl monomers with oligoperoxides as the initia-... 

The rates of radical-forming thermal decomposition of four families of free radical initiators can be predicted from a sum of transition state and reactant state effects. The four families of initiators are trarw-symmetric bisalkyl diazenes,trans-phenyl, alkyl diazenes, peresters and hydrocarbons (carbon-carbon bond homolysis). Transition state effects are calculated by the HMD pi- delocalization energies of the alkyl radicals formed in the reactions. Reactant state effects are estimated from standard steric parameters. For each family of initiators, linear energy relationships have been created for calculating the rates at which members of the family decompose at given temperatures. These numerical relationships should be useful for predicting rates of decomposition for potential new initiators for the free radical polymerization of vinyl monomers under extraordinary conditions. 

The polymer formation in the radical polymerization of vinyl monomers initiated by a usual initiator R-R is expressed by Eqs. (4) and (5) if termination proceeds via combination and disproportionation and no chain transfer reaction occurs. 

A fluorous biphasic system has been used to reduce the metal contamination arising in the copper-catalysed living radical polymerization of vinyl monomers. 

Vinyl Polymerization (383) Radical Polymerization of Vinyl Monomer with an Aqueous Solution of Polystyrenesulfonate or Polyvinylphosphonate... 

Hydrogels can be made by a number of methods, but one of the most widely used methods is free radical polymerization of vinyl monomers. Examples of vinyl monomers used in our laboratory are shown in Table 1. Monomers are crosslinked with divalent monomers such as A,A -methyl-enebisacrylamide. Biodegradable crosslinking agents can also be used as long as they have bifunctionality. 

Tab. 9.2 Specific surface modifications and SAM systems of particles or planar substrates for the surface-initiated free radical polymerization of vinyl monomers. 

Other catalytic reactions involving a transition-metal allenylidene complex, as catalyst precursor or intermediate, include (1) the dehydrogenative dimerization of tributyltin hydride [116], (2) the controlled atom-transfer radical polymerization of vinyl monomers [144], (3) the selective transetherification of linear and cyclic vinyl ethers under non acidic conditions [353], (4) the cycloisomerization of (V2V-dia-llyltosylamide into 3-methyl-4-methylene-(V-tosylpyrrolidine [354, 355], and (5) the reduction of protons from HBF4 into dihydrogen [238]. 

Eastmond, G. C., The Kinetics of Free Radical Polymerization of Vinyl Monomers in Homogeneous Solutions, Chap. 1 in Comprehensive Chemical Kinetics, Vol. 14A, C. H. Bamford and C. F. H. Tipper, eds., American Elsevier, New York, 1976a. 

The following experiment describes the background of free radical polymerizations of vinyl monomers. This information will be experimentally illustrated in experiments involving bulk and emulsion polymerizations of styrene. 

By way of example, let us consider how radical polymerization of vinyl monomers is initiated by free hydroxyl radicals. These radicals are obtained by catalytic action of bivalent iron salts on H202 dissociation (Fenton reagent) [15] ... 

The induction action of H202 on many reactions implemented in the temperature range 50-115 °C [32, 33] is well known. Free hydroxyl radicals can be generated in the radical polymerization of vinyl monomers using the Fenton reagent [34, 35],... 

INVESTIGATION OF LOW-TEMPERATURE RADIATION LIVING RADICAL POLYMERIZATION OF VINYL MONOMERS WITH FULLERENE C60 BY OPTICAL SPECTROSCOPY... 

H). Transfer to polyalkenes is similar when these are present during radical polymerization of vinyl monomers. Cross-linking transfer was also observed in ionic polymerizations [27]. 

In this special volume on polymer particles, recent trends and developments in the synthesis of nano- to micron-sized polymer particles by radical polymerization of vinyl monomers in environmentally friendly heterogeneous aqueous and supercritical carbon dioxide fluid media are reviewed by prominent worldwide researchers. Polymer particles are prepared extensively as synthetic emulsions and latexes, which are applied as binders in the industrial fields of paint, paper and inks, and films such as adhesives and coating materials. Considerable attention has recently been directed towards aqueous dispersed systems due to the increased awareness of environmental issues. Moreover, such polymer particles have already been applied to more advanced fields such as bio-, information, and electronic technologies. In addition to the obvious commercial importance of these techniques, it is of fundamental scientific interest to completely elucidate the mechanistic details of macromolecule synthesis in the microreactors that the polymer particles in these heterogeneous systems constitute. 

GAPDS and AMPH can also be employed, first in the synthesis of the corresponding polypeptide initiators containing -S-S- or N=N groups and then submitted to photolysis, thus giving the free radical polymerization of vinyl monomers (Scheme 48). 

In general, a polymerization process model consists of material balances (component rate equations), energy balances, and additional set of equations to calculate polymer properties (e.g., molecular weight moment equations). The kinetic equations for a typical linear addition polymerization process include initiation or catalytic site activation, chain propagation, chain termination, and chain transfer reactions. The typical reactions that occur in a homogeneous free radical polymerization of vinyl monomers and coordination polymerization of olefins are illustrated in Table 2. 

To illustrate the calculation of molecular weight averages using moment equations, let us consider a free radical polymerization of vinyl monomers. Table 3 shows the kinetic equations based on the kinetic... 

Each of the above methods for controlling the radical polymerization of vinyl monomers has its strengths and weaknesses. For example, the rates in ATRP can be easily adjusted through both the amount and activity of the transition metal complexes (both activator and deactivator). Faster rates in RAFT require larger amounts of initiators, i.e., more uncontrolled chains, while faster NMP requires less persistent radicals, which may result in more termination higher polydis-persities. At the same time, transition metal complexes, although not attached to the polymer chains, require removal and can potentially be recycled. 

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