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Modelling the Complete Molecular Weight Distribution in Chain Growth Polymerizations

Published online by Cambridge University Press:  05 July 2016

Ramiro Infante-Martínez
Affiliation:
Centro de Investigación en Química Aplicada, Saltillo, Coahuila. México
Enrique Saldívar-Guerra
Affiliation:
Centro de Investigación en Química Aplicada, Saltillo, Coahuila. México
Odilia Pérez-Camacho
Affiliation:
Centro de Investigación en Química Aplicada, Saltillo, Coahuila. México
Maricela García-Zamora
Affiliation:
Centro de Investigación en Química Aplicada, Saltillo, Coahuila. México
Víctor Comparán-Padilla
Affiliation:
Centro de Investigación en Química Aplicada, Saltillo, Coahuila. México
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Abstract

This work shows the development of several models for chain-growth polymerizations that admit the direct calculation of the complete molecular weight distribution of the polymer. The direct and complete calculation implies that no statistical mean values are employed as in the moments method neither numerical approximations like in the minimum-squared based methods. The free radical polymerization of ethylene (LDPE) and the coordination via metallocenes polymerization of ethylene (HDPE) are taken as examples for analysis.

In the free radical polymerization case, the conventional scheme for chain-growth polymerization is adopted, with steps for initiation, propagation, chain transfer to small species and the additional step of chain transfer to dead chains [1]. The kinetic parameter are obtained from the open literature. Two kind of reactors were modelled: batch and continuous stirred tank reactor. For this last case, a simulation strategy was considered in which the run started from an initial known population of dead chains. Results show that typical non-linear polymerization profiles for the molecular weight distribution are obtained. For the coordination polymerization of ethylene via metalocenes, the standard coordination model was employed [2]. A two-site catalyst was considered and kinetic parameters reported in the open literature were used. For this study an experimental program in a lab-scale reactor was undertaken in order to obtain modelling data [3]. Results show that the standard model adequately reproduces the experimental data in the kinetic and molecular attributes of the polymer.

Type
Articles
Copyright
Copyright © Materials Research Society 2016 

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References

REFERENCES

Asua, J. M., Polymer Reaction Engineering, Blackwell Publishing, (2007) p. 29 CrossRefGoogle Scholar
Soares, J. B. P., Chem. Eng. Sci., 56, 41314153, (2001).CrossRefGoogle Scholar
Ramiro, Infante M., Enrique, Saldívar G, Odilia, Pérez C., Víctor, Comparán P., Marisela, García Z., Journal of Applied Polymer Science, 131(6), March 15, (2014)Google Scholar
Wulkow, M., Deuflhard, P., “Towards an Efficiente Computational Treatment of Heterogeneous Polymer Reactions“, Preprint SC 90–1 Konrad-Zuse-Zentrum für Informationstechnik Berlin, (1990)Google Scholar
Wulkow, M.“Computer Aided Modeling Engineering. The Status of Predici, 1. Simulation”, Macromolecular Reaction Engineering 2(6) 461494 (2008).CrossRefGoogle Scholar