Assessment of the chemical changes during storage of phenol-formaldehyde resins pyrolysis gas chromatography mass spectrometry, inverse gas chromatography and Fourier transform infra red methods

•Py-GCMS, IGC is useful technique for assessment of the storage processes.•IGC was the most sensitive method on the changes of the resins during their storage.•During the resins storage only small changes in their chemical composition occur.•The chemical changes in resins are connected with the partial curing of resins.

The chemical changes occurring in the phenol-formaldehyde resins (resol and novolac type) during their storage were investigated. In this paper the FT-IR, py-GCMS and inverse gas chromatography methods were applied for assessment of the changes occurring during storage of the phenolic resins. We have found that during storage some examined resins occurred partial curing. The results from all techniques applied are consistent. Py-GCMS is useful technique for screening the storage processes but IGC seems to be most sensitive one.