Carbon black modified with 4-hydroxymethylbenzenediazonium salt as filler for phenol-formaldehyde resins and abrasive tools

Although phenol-formaldehyde (PF) resins possess excellent properties, they emit toxic substances during the decomposition of the crosslinking agent. Therefore, studies are being carried out on the fillers, which can reduce the amount of crosslinking agent. In this article, the synthesis of diazonium-modified carbon black was conducted. Diazonium modification allows the effective incorporation of hydroxymethyl groups, which are responsible for the crosslinking of PF resins. Modified materials were used as active fillers in the PF composites and abrasive tools. Due to carbon modification, flexural strength increases 26% for PF resin composite and 1100% for abrasive tools. The increase is related to the resulting covalent bonds between the resin and the modified filler. Therefore, it can be stated that application of active filler improves the properties of novolac composites and abrasive tools. The use of this type of fillers may affect the reduction of the amount of crosslinking agent in the future. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48160.