Kinetics of thermal degradation of poly(\varepsilon-caprolactone)

Sivalingam, G and Karthik, R and Madras, Giridhar (2003) Kinetics of thermal degradation of poly(\varepsilon-caprolactone). In: Journal of Analytical and Applied Pyrolysis, 70 (2). pp. 631-647.

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Abstract

The thermal degradation/modification dynamics of poly(\varepsilon-caprolactone) (PCL) was investigated in a thermogravimetric analyzer under non-isothermal and isothermal conditions. The time evolution of the molecular weight distribution during degradation was studied using gel permeation chromatography. Experimental molecular weight evolution and weight loss profile were modeled using continuous distribution kinetics. The degradation exhibited distinctly different behavior under non-isothermal and isothermal heating. Under non-isothermal heating, the mass of the polymer remained constant at initial stages with rapid degradation at longer times. The Friedman and Chang methods of analysis showed a 3-fold change (from 18 to 55–62 kcal $mol^{-1}$) in the activation energy from low temperatures to high temperatures during degradation. This suggested the governing mechanism changes during degradation and was explained using two parallel mechanisms (random chain scission and specific chain end scission) without invoking the sequential reaction mechanisms. Under isothermal heating, the polymer degraded by pure unzipping of specific products from the chain end.

Item Type:	Journal Article
Publication:	Journal of Analytical and Applied Pyrolysis
Publisher:	Elsevier
Additional Information:	The Copyright belongs to Elsevier.
Keywords:	Pyrolysis;Poly(var epsilon-caprolactone);Activation energy;Continuous distribution kinetics;Chain scission
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	03 May 2006
Last Modified:	19 Sep 2010 04:26
URI:	http://eprints.iisc.ac.in/id/eprint/6546

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