Effect of Metal Oxides on Thermal Degradation of Poly(vinyl acetate) and Poly(vinyl chloride) and Their Blends

Sivalingam, G and Karthik, R and Madras, Giridhar (2003) Effect of Metal Oxides on Thermal Degradation of Poly(vinyl acetate) and Poly(vinyl chloride) and Their Blends. In: Industrial and Engineering Chemistry Research, 42 (16). pp. 3647-3653.

PDF ie030009k.pdf Restricted to Registered users only Download (2kB) | Request a copy

Abstract

The role of metal oxides on the thermal decomposition of poly(vinyl chloride) (PVC) and poly(vinyl acetate) (PVAC) and their blends was investigated by thermogravimetry (TGA). While the degradation of PVAC was mildly affected by the presence of metal oxides, the degradation of PVC was greatly influenced by metal oxides. Both polymers followed a two-step degradation mechanism involving chlorine or acetate radical removal followed by polyolefinic backbone breakage. The isokinetic temperatures and rate determined from the compensation plots indicated that the mode of olefinic backbone breakage is the same for both the polymers. FTIR studies after the first stage showed the disappearance of the C-Cl of PVC and C=O and C-O groups of PVAC, suggesting the formation of a polyolefinic chain. Blends of PVC-PVAC were obtained by solution blending by dissolving the polymers in tetrahydrofuran. Scanning electron microscopy and TGA showed complete miscibility of polymers in the blend. The first-stage degradation of the blend was greatly influenced by the presence of PVC and metal oxides, suggesting that hydrogen chloride liberated from PVC influenced the decomposition behavior of PVAC. The second-stage degradation (olefinic breakage) of the blends was mildly affected by the metal oxides and the breakage was similar to that of pure polymers.

Item Type:	Journal Article
Publication:	Industrial and Engineering Chemistry Research
Publisher:	American Chemical Society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Keywords:	Pyrolysis;Polyvinyl chlorides;Oxides;Metallic compounds;Polymer blends;Reaction kinetics;Chemical bonds;Free radicals;Solubility;Thermogravimetric analysis;Fourier transform infrared spectroscopy;Scanning electron microscopy
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	11 Apr 2007
Last Modified:	19 Sep 2010 04:36
URI:	http://eprints.iisc.ac.in/id/eprint/10155

Actions (login required)

View Item