ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The equilibrium and the kinetics of the ring-opening polymerization accompanied with backbiting and end-to-end ring closure are analyzed using computer simulation. The influence of monomer ring strain and competition between back-biting and end-biting on the overall kinetic process is evaluated. The results of calculations are compared with examples from the ionic ring opening polymerization of heterocyclic monomers. It is established that in the polymerization of nonstrained monomers fast end-biting manifests itself by an induction period. In the absence of end-biting the polymerization of strained monomers yields a system in which the polymer concentration is temporarily higher than at equilibrium (kinetic enhancement in polymer). On the other hand, very fast end-biting, hindered only in the case of the monomeric species by the ring strain, results in concentrations of the macrocyclics which are transitorily higher than the corresponding equilibrium concentrations (kinetic enhancement of macrocycles). The polymer synthesis with kinetically controlled concentration of cyclics is indicated.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1985.021861219
