Preparation of an Abrasive Grinding Wheel Based on Tannin Resin Cross- Linked by Furfuryl Alcohol, Urea and Glyoxal

Simple bio-based abrasive grinding wheel based on thermosetting resin matrix was developed starting with condensed tannin and furfuryl alcohol,which are mainly derived from forest and agricultural products like tree barks,wheat and crops.Fourier transform infrared spectra(FTIR)signified the acidic conditions are quiet efficient for the reaction of furfuryl alcohol,urea and glyoxal all together and the-CH_(2)-NH-and-CH_(2)-O-CH(OH)-groups are predominating in cross-linking of the tannin-furfuryl alcohol-urea-glyoxal(TFUG)resin.The strengthening contribution of the tannin was also confirmed by the preservation of its distinct crystallinity using X-ray diffraction(XRD).Differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA)ensured that TFUG resin can be cured at low temperature and offer higher heat resistance compared with phenol-formaldehyde(PF)resin.The high hardness and excellent compressive strength revealed by the corresponding investigations such as Brinell hardness,compression resistance,and grinding tests suggested a strong abrasive ability using the new grinding wheel compared with lab-made grinding wheel based on PF resin.This could be ascribed to the absence of cracks and low content of formed holes as confirmed using scanning electron microscopy(SEM)and balanced reaction conditions that leads to network structure with regular local reinforcements and homogeneous crosslink density.