Preparation and performance of tannin-glyoxal-urea resin-bonded grinding wheel loaded with SiO2 reinforcing particles

Jun Zhang,Yunxia Zhou,Bowen Liu,Hisham Essawy,Qian Chen,Jinxin Li,Xiaojian Zhou,Guanben Du

doi:10.4067/s0718-221x2021000100448

Jun Zhang, Yunxia Zhou + Show 6 more

Open Access

https://doi.org/10.4067/s0718-221x2021000100448

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Abstract

In this study, an easily prepared bio-based abrasive grinding wheel based on tannin-glyoxal-urea (TGU)thermosetting matrix is presented.The synthesised resin was prepared via co-polycondensation reaction of glyoxal and ureawith condensed tannin, which is a forest-derived product. Fourier transform infrared spectroscopy and electrospray ionisation mass spectrometry results confirmed that urea and glyoxal react well under acidic conditions and that -(OH)CH-NH-group is primarily involved in TGU cross-linking. Differential scanning calorimetry, thermomechanical analysis and thermogravimetric analysis investigations showed that the preparation of TGU resin is easier compared to commercial phenol-formaldehyde (PF) resin; moreover, TGU resin has a more robust chemical network structure, which contributes efficiently to heat resistance and improved mechanical properties. This observation is supported by Brinell hardness, compression resistance and grinding testing; these showed that the new grinding wheel acquired higher hardness, superior resistance against compression and stronger abrasion resistance compared with a PF-based grinding wheel prepared in the laboratory. Moreover, few holes and no cracks were found in the new grinding wheel.

Highlights

Grinding wheels are frequently used for processing materials in construction, interior decoration, mechanical manufacturing and other fields (Li et al 2020, Klocke et al 2015, Manoharan et al 2015)
Commercial urea was procured from Huairenzhongan Chemical Plant (Jiangxi, China) while liquefied phenol (80 %) and sodium hydroxide were procured from Fisher Scientific (Loughborough, UK)
The C-O stretching of phenols in the mimosa tannin (MT) structure is represented by an absorption band at 1284 cm−1, while in case of TGU1, it is represented by two absorption bands at 1225 cm−1 and 1207 cm−1

Summary

Introduction

Grinding wheels are frequently used for processing materials in construction, interior decoration, mechanical manufacturing and other fields (Li et al 2020, Klocke et al 2015, Manoharan et al 2015). Phenol-formaldehyde (PF) resin has been widely employed as a binder for the preparation of abrasive materials (Robie 1957, Rowse and Stinchfield 1959, Wang et al 2011, Luo et al 2012). Considerable research has been performed on tannin originating from forests (Pizzi 1994, Pasch et al 2001) to develop a new environmentally friendly and low-cost resin as a substitute for preparing grinding wheels. The reactivity at positions 6 and 8 of aromatic ring A is high; electrophilic substitution with cations is easy. At position 4 of aromatic ring A, nucleophilic substitution with anions is most favourable. Electrophilic activity at position 8 is higher compared to that at position 6 because position 8 is closer to heteroepoxy in aromatic ring A (Tondi et al 2008c)

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