Matrix Representation of Polymer Chain Size Distributions, 2 : Fundamental Analysis of Linear Polymerization Mechanisms at Transient Conditions

✍ Scribed by Heloísa L. Sanches; Príamo A. Melo; José Carlos Pinto

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 284 KB
• Volume: 16
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/mats.200600068

✦ Synopsis

Abstract

Analysis of the mass balance equations that describe a reaction system may be useful to provide information about its dynamics, such as the restricted set of compositions that can be achieved from a given set of initial compositions and the effect of feeding reactants to the reaction environment along the reaction course. Since these results may be important for the formulation of reaction policies, this work presents the properties of a matrix polymerization model previously developed and extended to describe transient conditions. This model is based on the definitions of two matrices: the consumption matrix (A − Kt), which contains information about chemical transformations among the many active polymer species in the system, and the propagation matrix Kp, which contains information about chain growth. It is shown that the set of mass balance equations that describes the dynamics of active chemical species in polymerization reactions has a stable and unique solution, which is bounded if feed rates are also bounded. It is also shown that the set of compositions that may be reached through manipulation of the feed rates is restricted and may not include all possible chemical compositions. Finally, it is shown that the obtained molecular weight distributions are special multiple time convolutions of the initiation rates.

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