Page 450 - Handbook of Materials Failure Analysis

448 CHAPTER 17 Application of pyrolysis

FIGURE 17.3
(a) Imaging of the investigated rubber membrane from the automotive pressure vessel.
(b) Imaging of the defective surface of the rubber membrane from the automotive pressure
vessel.

(see Table 17.1). The presence of phenol (RT¼15.40 min) and cresol isomers
(RT¼16.64and16.99 min)inthepyrolyzateischaracteristicforthethermaldegradation
of phenol resin. The peaks of benzofuran (RT¼15.87 min) and acetophenone
(RT¼17.13 min) were assigned to PET. Other substances that appear in pyrograms in
Figure17.4havebeenidentifiedbyEIMSasadditivesortheirthermaldegradationprod-
ucts. The peak of benzothiazole (RT¼20.40 min) corresponds to the product ofthe ther-
mal decomposition of benzothiazole-2-thiol (2-mercaptobenzothiazole, 2-MBT). In the
rubber industry, benzothiazole-2-thiol is used as vulcanization accelerator andas antiox-
idant.Oneofthemainusesof2-phenoxyethylacrylate,identifiedatRT¼24.74 min,isin
coatings on glass, metal, paper, plastic, wood, and PVC floor coatings. Phenoxyethanol
identifiedatRT¼19.88 minisuseduponotherapplicationsassolventandplasticizerfor