Polymer size, reactivity influenced

It is most fortunate for the development of polymer science that these imagined complications have turned out to be almost wholly illusory. As will be brought out in the course of this chapter, the influence of molecular size and complexity on chemical reactivity may be disregarded in very nearly all polymer reactions. If this were not the case, application of the principles of reaction kinetics to polymerization and polymer degradation reactions would be difficult, and might be so complicated as to be fruitless. Not only would polymer reaction kinetics... 

Davidjan et. al.166) have made a study of the influence upon the propagation of poly(isoprenyl)lithium in n-hexane of very small additions of 1,2-dimethoxyethane (DMEractive centers = 0.01). Analysis of polymer obtained at 10% conversion by size exclusion chromatography coupled with a determination of the dependence of the stereochemistry upon molecular weight led them to the conclusion that complexation reduces the reactivity of what they assumed to be the most reactive species, i.e., the non-associated active center. 

The reactivity of a liquid-solid-liquid triphase reaction (i.e., polymer-supported catalytic reaction) is influenced by the structure of the active sites, particle size, degree of cross-linkage, degree of ring substitution, swollen volume, and spacer chain of a catalyst pellet. In the past, the characteristics of a triphase reaction, subjected to the mass transfer limitation of the reactants and ion-exchange rate in the aqueous phase, have been discussed [146,158,162,178,179]. The ion-exchange rate in the aqueous phase affects the reactivity of the triphase reaction. 

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