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Effect of segregation on the course of unpremixed polymerizations
Author(s) -
Fields S. D.,
Ottino J. M.
Publication year - 1987
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690330609
Subject(s) - mixing (physics) , polyurethane , polymerization , molar mass distribution , layering , component (thermodynamics) , product (mathematics) , catalysis , block (permutation group theory) , chemistry , materials science , polymer chemistry , chemical engineering , thermodynamics , composite material , organic chemistry , mathematics , physics , polymer , geometry , engineering , botany , quantum mechanics , biology
Reactant segregation and mixing effects can be represented by a one‐dimensional distribution of alternating reactive liquid layers. This paper reports a theoretical study of the influence of this configuration on the course of three‐component, random block copolymerizations. Two models that follow the interdiffusion of the reacting species and the catalyst are considered. The first employs a lumped competitive‐parallel kinetic scheme to represent the formation of hard and soft segments; the second uses a moment formulation to handle the polymerization. The results are intended for the description of mixing‐activated three‐component polyurethane systems, but conclusions of a general nature are obtained. Several unexpected results are presented regarding the molecular weight buildup and spatial product segregation in the system. In particular, it is established that reactant segregation may severely influence product segregation (layering), the average molecular weight, and the maximum molecular weight achieved.