Authors Lang, M. ; Göritz, D. ; Kreitmeier, S.
Title Intra-Molecular Reactions in End-Linked Polymer Networks and Linear (Co)Polymerizations
Date 09.02.2005
Abstract This work studies intramolecular reactions in irreversible linear and nonlinear random (co)polymerizations with computer simulations. We find a relative rate for the formation of rings of i chains proportional to i-3/2 in agreement with predictions of rate theory based on Gaussian chain statistics. This result is used to develop a general ansatz for ring formation in irreversible random polymerizations or in cyclization equilibria. Using the approximation cext cint for the concentrations of reactive groups on the external molecules cext and on the selected molecule cint, this ansatz reduces to a result previously found by Suematsu. In this special case we find that the ring size distribution Ri is proportional i-5/2[(f - 1)(g - 1)pApB]i-1, where f and g denote the functionality of two different types of molecules A and B, and pA and pB are the conversions of the reactive groups on the molecules, respectively. Our findings explain preceding experiments, simulations, and all results within this work as well as we can discuss the limitations of previous theoretical approaches.
Journal Macromolecules 38 (2005) 2515–2523

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