Analytical pyrolysis of waste paper laminated phenolic-printed circuit board (PLP-PCB)

The pyrolysis of a paper laminated phenolic-printed circuit board (PLP-PCB) was investigated. Kinetic analysis revealed the pyrolysis of PLP-PCB to be composed of a series reaction distinguished by the DTG curve and four activation energy regions: (1) vaporization of phosphorous flame retardants (<280 degrees C), (2) pyrolysis of laminated paper and tetrabromo bisphenol A (TBBA) (280-370 degrees C), (3) pyrolysis of phenolic resin (370-500 degrees C), and (4) stabilization of the char intermediate (>500 degrees C). The evolved gas analysis-mass spectrometry (EGA-MS) and heart cut EGA-gas chromatography (GC)/MS results showed that large amounts of phosphate flame retardants which can be reused as additives were recovered below 280 degrees C. Because the paper and TBBA had almost the same decomposition temperature regions, the pyrolyzates of laminated paper, mainly levoglucosan, were produced together with the pyrolyzates of TBBA, mainly brominated bisphenol between 280 and 370 degrees C. Important chemical feedstock, such as phenol, cresols and other alkylated phenols were produced from the decomposition of phenol resin between 370 and 500 degrees C, and aromatic compounds were emitted as the byproducts of char stabilization reaction at temperatures higher than 500 degrees C. (C) 2015 Elsevier B.V. All rights reserved.