Qualitative and quantitative analysis of a thermoset polymer, poly(benzoxazine), by pyrolysis–gas chromatography

The chemical composition of a poly(benzoxazine) thermoset polymer (a copolymer of bisphenol-A benzoxazine and tert.-butylphenol benzoxazine) has been studied by pyrolysis–gas chromatography (Py–GC). Major pyrolysates have been identified and the possible degradation pathways have been investigated. A specific pyrolysate was identified for quantitative analysis after carefully proving the linear relationship between the pyrolysate signal intensity and monomer concentration over a wide range of compositions. A method to determine the concentration of the monomer that potentially acts as a cross-linking unit has been developed. In this study, Py–GC was shown to be an excellent analytical technique for the qualitative and quantitative analysis of thermoset polymers.