Evolution to similarity solutions for polymerization and depolymerization with microwave radiation

Madras, Giridhar and Karmore, Vishal (2001) Evolution to similarity solutions for polymerization and depolymerization with microwave radiation. In: Polymer International, 50 (12). pp. 1324-1330.

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Abstract

The kinetics of polymerization and depolymerization are critical in understanding the stability and characterization of polymers. The kinetics of simultaneous polymerization and degradation of poly(methyl methacrylate) have been investigated by varying the initiator concentration and monomer concentration under the influence of microwave energy. Microwave radiation initially polymerizes the monomer, then degrades the resulting polymer and the polymer attains an equilibrium molecular weight distribution with a polydispersity of two. To understand more fully the kinetics, the molecular weight distribution (MWD) is represented as a gamma distribution; the random degradation rate coefficient is assumed to vary linearly with molecular weight and the polymerization rate coefficient is assumed to be independent of molecular weight. The change of the MWD with time is studied by continuous distribution kinetics; the solutions obtained depict the change of the average molecular weight, polydispersity and the gamma distribution parameters with time. Experimental data indicate that reaction rates are enhanced by microwave radiation and the MWD approaches a similarity solution within 10 min for all the investigated cases. The model satisfactorily predicts the change of the MWD with time.

Item Type:	Journal Article
Publication:	Polymer International
Publisher:	John Wiley and Sons
Additional Information:	Copyright of this article belongs to John Wiley and Sons.
Keywords:	Addition reactions;molecular weight distributions;similarity solutions;polymerization;polymer degradation;distribution kinetics;microwave radiation.
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	18 Aug 2008
Last Modified:	19 Sep 2010 04:49
URI:	http://eprints.iisc.ac.in/id/eprint/15554

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