Regeneration and utilization of waste phenolic formaldehyde resin: A performance investigation

Abstract

ABSTRACTRecycled thermosetting phenolic formaldehyde (RPF) resins were pulverized to micron‐sized powders and successfully reused as an effective component by reactive‐injecting with neat phenolic formaldehyde (PF) and/or trioxymethylene (TOX) to prepare regenerated phenolic formaldehyde (i.e., and ). Tensile strength (σf), impact strength (Is), and density (ρ) of and specimens were reduced as RPF concentrations or average particle sizes increased. It is worth emphasizing that σf, Is, and ρ of each reaction‐injected series having a fixed RPF concentration and average particle size improved to a maximum value, as TOX concentrations reached a corresponding optimal value. This is the first investigation to report that σf and Is of proper regenerated PF/RPF/TOX specimens using ≦20 wt % RPF waste were ≥ 95% of those of the virgin reaction‐injected PF. Possible reasons accounting for these improved mechanical properties were proposed based on results from their Fourier transform infrared analysis (FTIR). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47445.