Influence of modified graphite on formaldehyde emission from medium density fiberboard (MDF)

Abstract

In this study, the effect of graphite and two modified graphite materials was investigated in reducing formaldehyde emission from medium density fiberboard (MDF). For this purpose, expanded graphite (EG) was synthesized from graphite (G) and modified expanded graphite (MnO2-EG) was produced through the intercalation process of expanded graphite with manganese dioxide. Thus, three graphite materials were prepared for resin treatment. Molecular tests including X-ray diffraction (XRD) and X-ray diffraction spectroscopy (SEM-EDS) were performed to determine their molecular properties. In addition, the differential scanning calorimetry (DSC) test was performed to evaluate the thermal behavior of the resin under the influence of any graphite materials as an additive. The additives were added to urea formaldehyde resin at three levels of consumption of 1, 2 and 3%, and then medium density fiberboard (MDF) was made from glued fibers with a density of 750 kg/m3. After making the board, the formaldehyde emission test was performed by desiccator method. Overall, MnO2-EG showed better results than control and two other graphite treatments. The best performance was resulted using MnO2-EG at 3% and formaldehyde emission was reduced by about 61%. It seems that the formaldehyde molecules absorbed on the expanded graphite layers which are exposed to oxidation by manganese dioxide molecules. On the other hand, as the DSC test showed, the highest enthalpy reaction occurred in MnO2-EG-incorporated resin, indicating the increased chemical reaction with formaldehyde molecules in the UF resin structure.

Keywords

• uf resin
• expanded graphite
• manganese dioxide