ISSN:
0887-624X
Keywords:
ε-caprolactone
;
ring-opening polymerization
;
rare earth coordination catalyst
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Ring-opening polymerization of ε-caprolactone has been carried out by using rare earth coordination catalysts for the first time. The rare earth compounds, RE(acac)3.3H2O, Nd(P204)3, Nd(P507)3, Nd(naph)3, Nd(BA)3.2H2O, etc. (where RE = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Lu, Y; acac = acetylacetone; BA = benzoylacetone), combined with trialkyl aluminum, greatly increased the degree of conversion and the molecular weight of poly(ε-caprolactone) (PCL). The influence of reaction conditions on the polymerization of ε-caprolactone catalyzed by the Nd (acac)3.3H2O-AlEt3 system has been examined in detail. The kinetics indicates that the polymerization rate has the first-order in monomer and a half-order in catalyst. The overall activation energy of the ring-opening polymerization amounts to 59.4 kJ/mol. By IR and UV-Vis spectra, 1H- and 13C-NMR data, it is assumed that the ring-opening polymerization of ε-caprolactone catalyzed by the Nd(acac)3.3H2O-AlEt3 system proceeds via complexation of monomer to catalyst, acyl-oxygen cleavage insertion propagation mechanism. © 1994 John Wiley & Sons, Inc.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pola.1994.080320401
