Hybrid nanofiller reinforcement in thermoset and biothermoset applications: A review

Abstract Thermoset and biothermoset applications have been advancing tremendously in recent years due to their easy processing, versatility, and exceptional mechanical and thermal properties. Biothermoset is a type of thermoset that is produced using biological resources, either in portions by blending with the conventional resin, or completely. Various research has been employed to accommodate their high and rapidly growing demands and broaden their functions and implementation in numerous fields. One of these attempts is the reinforcement of nanofillers. Nanofillers such as nanoclay, graphene nanoplatelets, carbon nanotubes, nanodiamond, etc., possess diverse and outstanding properties and are also easily accessible. Recently, there has been a developing trend of hybridizing two or more types of nanofillers as a hybrid reinforcement system to address the limitations of single-filler reinforcement systems and to establish better-supporting properties of the nanocomposites. In this review, we discussed the use of hybrid nanofillers in different thermoset and biothermoset applications. Emphasis is given to the types of hybrids, their interactions with each other and the host polymer, and the effects of their contents and ratios. Limitations from the previous works are also discussed and the future undertaking of research on hybrid nanofillers is also proposed.