Synthesis of oil-based resin using pyrolysis oil produced by debromination pyrolysis of waste printed circuit boards.

Abstract Pyrolysis is a promising technology for disposing of waste printed circuit boards (WPCBs) with organics removal and materials recovery. However, pyrolysis oil contains various hazardous and carcinogenic components, leading to difficulty to reuse and refine. Therefore, novel methods for utilizing pyrolysis oil were needed. The purpose of this study is to reuse pyrolysis oil as raw material to synthesize oil-based resin. The pyrolysis oil was produced by argon pyrolysis of WPCBs at 600 °C and temperature-controlled condensation at 100 °C. The results showed that the optimum parameters for synthesizing oil-based resin were the mole ratio of phenols in pyrolysis oil and formaldehyde of 1:0.8, synthesis temperature of 90 °C, reaction time of 2.0 h, and HCl concentration of 5.0%. Besides, the kinetic model of curing reaction was established by Kissinger and Kaelble methods, which agreed well with the experimental data. The results of SEM, TG-DTG, FT-IR, and NMR indicated that oil-based resin had the similar morphology, thermostability, functional groups and chemical structure compared with commercial resin, indicating that the oil-based resin had huge economic value. Besides, other ingredients in pyrolysis oil participated in the synthesis process of oil-based resin, resulting in the decrease of oil-based resin molecular weight. The proposed mechanism of synthesis oil-based resin can be concluded as protonation, addition and condensation polymerization. This study raises a novel method to utilize pyrolysis oil effectively, sustainably and environmentally friendly. Graphical abstract Image 1 Highlights • Pyrolysis oil was collected and separated by temperature-controlled condensation technique. • Pyrolysis oil, as raw material, was used to synthesize oil-based resin. • The structure and thermostability of oil-based resin were similar to commercial resin. • Synthesis mechanism of oil-based resin was analyze. [ABSTRACT FROM AUTHOR]