Thermal-Oxidative Stability and Degradation of Polymers

Abstract

This chapter discusses thermal-oxidative stability and degradation of polymers. Thermal stability refers to the ability of a material to maintain desirable mechanical properties such as strength, toughness or elasticity at a given temperature. At the other extreme, thermal degradation can be defined functionally as the deterioration of those properties of polymers which make them useful commercially as rubbers, plastics and fibers. The structure-property relationships of polymers are provided. The oxidative degradation of polymers involves free-radical chain reactions. For example, degradation of polyolefins such as polyethylene (PE) is commonly initiated by hydroperoxide impurities incorporated during synthesis and processing. The polymers selected for discussion are polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(vinylchloride) (PVC), poly(acrylonitrile) (PAN), poly(tetrafluoroethylene) (PTFE), polyamides (PAs), and heat-resistant polymers. Enhanced stability has been achieved by the use of additives which are frequently called antioxidants or heat stabilizers. Polymer degradation can be monitored by measurement of molecular weight using viscometry, osmometry, light scattering, ultracentrifuge, and gel-permeation chromatography (GPC). The GPC (more generally called size-exclusion chromatography) can be used in estimating the effect of degradation on molecular-weight distribution (MWD). Spectroscopic probes of thermal degradation include ultraviolet (UV) spectroscopy, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, electron-spin resonance spectroscopy (ESR, EPR), and mass spectrometry (MS). Multiple internal reflectance infrared spectroscopy (MIRS) allows a very thin surface layer to be examined. Thermal-stability data extracted from a variety of sources in the literature on selected familiar and commercial polymers are tabulated.

Cite this page

References (23)

About this content

Title
Thermal-Oxidative Stability and Degradation of Polymers
Book Title
Physical Properties of Polymers Handbook
Book DOI
10.1007/978-0-387-69002-5
Chapter DOI
10.1007/978-0-387-69002-5_54
Part of
Volume
Editors
  • James E. Mark Send Email (1)
  • Editor Affiliation
  • 1 Department of Chemistry, University of Cincinnati, Crosley Tower, Martin Luther King Drive, 45221-0172, Cincinnati, OH
  • Authors
  • Vladyslav Kholodovych Send Email (2)
  • William J. Welsh Send Email (3)
  • Author Affiliation
  • 2 Department of Pharmacology, University of Medicine & Dentistry of New Jersey (UMDNJ), Robert Wood Johnson Medical School, 08854, Piscataway, NJ
  • 3 Department of Pharmacology, University of Medicine & Dentistry of New Jersey (UMDNJ), Robert Wood Johnson Medical School, 08854, Piscataway, NJ
  • Cite this content

    Citation copied