Utilization of activated carbon as an additive for urea-formaldehyde resin in medium density fiberboard (MDF) manufacturing

Abstract

In this study, the MDF sanding dust was examined as a precursor for synthesizing activated carbon (AC). For this purpose, MDF sanding dust was impregnated with KOH at two different weight ratios 1:0.50 and 1:1 (sanding dust/KOH). The process was done in one step at a temperature of 750 °C and a heating rate of 8 °C/min. The synthesized ACs at different content were added into urea-formaldehyde (UF) resin for medium density fiberboard (MDF) production. The laboratory MDF boards were produced using a hot press at a temperature of 190 °C and pressure of 40 MPa. The ACs content in UF resin was set at 0.25%, 0.50% and 1% based on the dry weight of the resin. The ACs were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The BET equation was used to determine the specific surface area of the AC samples. Water absorption, thickness swelling, internal bonding, flexural modulus and strength, and the formaldehyde emission from MDF boards were determined. The curing behavior of UF resins were evaluated using Differential Scanning Calorimetry (DSC). The results revealed that surface area and micropore volume of ACs increase with increasing KOH ratio; and the ACs exhibited three-dimensional porous network structures. The DSC results also showed that the ACs significantly increase the reaction enthalpy of UF resins. The addition of AC as an additive to UF resin significantly reduces formaldehyde release from MDF boards and improves their physical and mechanical properties.