Accessibility and catalytic activity of sulfonic acid ion-exchange resins in different solvents

Selective formation of triacetin by glycerol acetylation using acidic ion-exchange resins as catalyst and toluene as an entrainer

“…by contact with polar solvents and reactants, respectively, consequently changing the accessibility of the acidic sites (e.g. [30,31]). Another point is also the size of the reactants that might influence the molecular traffic inside such swelling resins.…”

Removal of caesium catalyst from polyols by ion exchange on Amberlite 252

“…At the beginning of copolymerisation the large reactivity of divinylbenzene makes its rate of polymerisation faster, leading to an inhomogeneity of crosslinking distribution in the particle. The nuclei is a region of relatively high crosslinking density, while there is a gradation of this parameter through the bead from the nuclei to the surface of the bead [36].…”

Enhancing MTBE rate equation by considering reaction medium influence

“…The resin structure is not wholly rigid in liquid media, so its conformation depends to some extent on the nature of the liquid; reactants with a higher affinity for the resin permeate easily and more deeply into the resin, and they can reach a larger number of active centers (Buttersack, 1989). On the other hand, the acidic strength of sulfonic groups depends on the solvating capacity of the medium.…”

“…It is directly related to the swelling of the resin backbone (Errede, 1986) and to the accessibility of active centers of a macroporous sulfonic resin (Buttersack, 1989). For compound i, 6 is defined by (Reichardt, 1988) (13) When referred to the reaction medium, 8, is also related to its polarity, since 6$, known as the cohesivepressure, represents the total strength of the intermolecular structure of this medium: 8; has very high values for solvents of high polarity and low values for nonpolar solvents with weak interaction forces (Reichardt, 1988).…”