Polymer monomer interactions

The monomer-polymer interaction is not negligible, i.e. fim,p 4= 0. The deviations due to variation of the partial volume of monomer... 

In conclusion, studies of the equilibria between living polymers and their monomers provide means of determining monomer-polymer interaction parameters, and interaction parameters of monomer and polymer with a solvent. 

When a sufficiently high concentration of polymer is formed at equilibrium, monomer-polymer interactions have to be taken into account. 

When interactions involving solvent are neglected or cancel each other (bulk polymerization), Eq. (2-12) reduces to its simpler form, involving only monomer-polymer interactions 14) ... 

The monomer-polymer interaction model, described above, requires sufficient steric hindrance at the active centers to prevent rotation of the penultimate units. Such rotation would cause the substituent to interfere with the incoming monomer. The fact that syndiotactic placement takes place only at low temperatures and atactic placement at elevated ones supports this concept. An illustration of the structure of the catalyst and the active center follows . ... 

Polymerization in the Liquid Crystalline State Monomer-Polymer Interactions... 

When the conversion of a monomer into a polymer unit is measured in bulk or at high [M]o, the monomer-polymer interaction cannot be neglected. The same is true when the measurements are made in a solvent interacting differently with the monomer and polymer. Under these conditions, the corresponding interactions have to be taken into account. If the... 

N59 Corrected for monomer-polymer interactions required temperature variable interaction parameter. 

Ivin and Leonard, starting from Flory-Huggins theory [54], derived an equation relating the volume fractions of monomer, polymer and solvent (Om. I p and Og), the monomer-solvent, polymer-solvent and monomer-polymer interaction parameters (%ms, Xps and x p) with the absolute (i.e. independent of the polymerization conditions) thermodynamic parameters [55] ... 

One major question of interest is how much asphaltene will flocculate out under certain conditions. Since the system under study consist generally of a mixture of oil, aromatics, resins, and asphaltenes it may be possible to consider each of the constituents of this system as a continuous or discrete mixture (depending on the number of its components) interacting with each other as pseudo-pure-components. The theory of continuous mixtures (24), and the statistical mechanical theory of monomer/polymer solutions, and the theory of colloidal aggregations and solutions are utilized in our laboratories to analyze and predict the phase behavior and other properties of this system. 

There are two general classes of imprinted polymers covalent and noncovalent MlPs. These two categories refer to the types of interactions between the functional monomer and the template in the prepolymerization complex. There are also hybrid MlPs that utilize a combination of covalent and noncovalent interactions in the preparation and rebinding events (Klein et al. 1999). Covalent MlPs utilize reversible covalent interactions to bind the template to the functional monomers. In contrast, noncovalent MlPs rely on weaker noncovalent functional monomer-template interactions. Each type has specific advantages and disadvantages with respect to sensing applications that will be addressed in subsequent sections. 

The fragmentation process depends on how much electrical energy (RF power) is supplied to maintain the plasma, how much monomer is introduced into the plasma, and where the monomer molecules interact with activated species of the plasma. Yasuda proposed a controlling parameter or W/FM value, where W, F, and M are RF power [J/s], the monomer flow rate [mol/s], and the molecular weight of the monomer [kg/mol], respectively [21]. The W/FM parameter is an apparent input energy per unit of monomer molecules [J/kg] therefore, the magnitude of the W/FM parameter is considered to be proportional to the concentration of activated species in the plasma. The polymer formation rate (polymer deposition rate) increases by increasing the W/FM parameter in the operational condition, whereby... 

For instance, it has been shown for PEO (oligomer) — PMA (polymer) interaction that the reaction heat calculated per monomer unit does not depend on the DP of the oligomer26). Then the probability of oligomer-polymer association is... 

A major factor in the interaction of the two phenols during oxidation, making the dimethylphenol appear less reactive and diphenylphenol more reactive than expected, must be the monomer-polymer redistribution reaction. Redistribution of diphenylphenol with the low oligomers... 

A fluorescent MIP chemosensor for determination of 9-ethyladenine was fabricated [56]. It contained porphyrin as a luminescent functional monomer. The interaction of 9-ethyladenine with the porphyrin quenched the MIP luminescence at 605 nm when excited at 423 nm. The polymer was sensitive to 9-ethyladenine in the range of 0.01-0.1 mM however, it was already saturated at 0.15 mM. The same researchers used vinyl-substituted zinc(II) porphyrin and methacrylic acid as functional monomers for imprinting of (-)-cinchonidine [57]. The MIP luminescence, when excited at 404 nm, was significantly quenched at 604 nm upon binding of (-)-cinchonidine, even in the low concentration range of 0.01-2 mM. 

The molecular weight of the backbone polymer is another important factor. No interactions between the monomer and dimer models were observed under the conditions examined, nor was there any apparent interaction between the monomer model and the polymer. Interactions between the dimer models and their complementary polymers occur only at higher concentrations. In order to realize a stable complex formation, the molecular weight of the polymers should be high enough, as in the case of polynucleotides39. ... 

Template polymerization as seen in replicative biopolymer synthesis has recently received attention. From this point of view, vinyl polymerization has been studied in the presence of polymers that were expected to serve as templates. These template polymerizations, however, do not appear to be strictly selective because interactions between the monomeric or polymeric spedes and the template polymers may not readily be realized. It seems, however, to be one of the most attractive problems if template polymerization can be followed by suitable monomer-polymer pair formation with complementary nucleic acid bases. This section deals with the free-radical polymerization of methyacryloyloxy type monomers with pendant bases in the presence of template polymers with complementary bases41,42). 

---