Effect of ZnCl2 Treatment Parameters on the Thermo-Hydrolysis of Recycled MDF for Epoxy Composites

Abstract

The aim of this study is to determine the hydrothermal recycling of medium-density fiberboard (MDF) wastes using zinc chloride (ZnCl2) as an acidic catalyst to obtain reinforcing fibers for epoxy-based composites. For this purpose, during the hydrothermal recycling process (110 °C, 0.4 bar), zinc chloride solutions with different concentrations (0% to 30%) were applied at different time intervals (20 to 60 min). The recycled fibers were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope-energy dispersive spectrometry (SEM-EDS), carbon (C) (%), hydrogen (H) (%), and nitrogen (N) (%) contents, and fiber classification. The fibers were added as a filler (1% w/w) to epoxy composites. The compression strength and of the epoxy composites as assessed and differential scanning calorimetry (DSC) characterization was performed. According to the results, nitrogen content decreased with increasing ZnCl2 concentration. Furthermore, the fine fibers ratios increased with increasing treatment time. The results suggest that recycled fibers can be used as a filler in epoxy composites; however, a long treatment time adversely affects the compression strength of epoxy composites.