ISSN:
0887-624X
Schlagwort(e):
poly (ethylene naphthalate)
;
transesterification kinetics
;
reaction order
;
activation energy
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The transesterification of dimethyl naphthalate (DMN) with ethylene glycol (EG) was kinetically investigated in the presence of various catalysts at 185°C. The transesterification was assumed to obey first-order kinetics with respect to DMN and EG, and a rate equation was derived. The rate constant of transesterification which was calculated from the quantity of methanol which distilled from the reaction vessel was used to evaluate the activity of each metal compound. The first-order dependence on the catalyst concentration is valid below a critical concentration which was found to be dependent on the catalyst type. The order of decreasing catalytic activity of various metal ions was found to be: Pb ≥ Zn 〉 Co 〉 Mg 〉 Ni ≥ Sb, but in the case of highly basic metal salts, the rate constants were found to be extremely large at the initial stage of the reaction, and then rapidly decreased with the progress of the reaction. Effects of reaction temperature were also discussed. The activation energies for zinc acetate and lead acetate were 97.84 and 108.8 kJ/mol, respectively, which were calculated from the Arrhenius equation. © 1994 John Wiley & Sons, Inc.
Zusätzliches Material:
17 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pola.1994.080320710
