Thermal Degradation of Polyoxymethylene Evaluated with FTIR and Spectrophotometry

Abstract

Thermooxidative degradation at and beyond processing temperatures of a polyoxymethylene copolymer has been progressively accelerated to carbonisation through oven-storage aging. The quantification of such degradation was carried out through FTIR spectrography and colour spectrophotometry methods. The state of thermo-oxidation was monitored through the FTIR spectra corresponding to the carbonyl aldehyde group (O=CH) and methylene bending (–CH₂), as well as the chromaticity changes experienced on the sample surface. The results showed that the FTIR bands suggested are a reliable indicator during the initial conditions of degradation, however, the spectrophotometry becomes more appropriate method for more aggressive conditions leading to carbonisation.

Keywords:

• Degradation
• FTIR
• Polyoxymethylene
• Spectrophotometry

ACKNOWLEDGMENTS

The authors, in general, would like to acknowledge the Ministerio de Educación y Ciencia of the Spanish Government for the financial support given through the project PSE-020400-2006-1. In addition Mr. Vilà is particularly grateful for the support received from Universitat Politecnica de Catalunya and Centre Català del Plastic.