Characterization of Agricultural and Food Processing Residues for Potential Rubber Filler Applications

Abstract

Large volumes of agricultural and food processing residues are generated daily around the world. Despite the various potential uses reported for this biomass, most are still treated as waste that requires disposal and negatively impacts the environmental footprint of the primary production process. Increasing attention has been paid toward the use of these residues as alternative fillers for rubber and other large-scale commodity polymers to reduce dependence on petroleum. Nevertheless, characterization of these alternative fillers is required to define compatibility with the specific polymer, identify filler limitations, understand the properties of the resulting composites, and modify the materials to enable the engineering of composites to exploit all the potential advantages of these residue-derived fillers.

Torrefied agro‐industrial residue as filler in natural rubber compounds

“…In addition, a significant fraction of the material was composed of smaller particles at about 8 μm (Figure 6). The TRH sample also had a similarly broad particle size distribution (Figures 6) and contained irregular particle shapes including rod‐shaped and other non‐spherical shapes in a range of sizes (~2–120 μm) with evidence of larger pores than for TAS, similar to those reported for rice hull ash 8 and other biobased fillers 2 . The moderately rough surfaces of the TAS and TRH fillers may favor mechanical polymer matrix/filler adhesion (the matrix could ''grip'' the rough surfaces).…”

“…In general, mechanical properties for compounds replacing carbon black with TAS and TRH show similar trends to reports for other biobased fillers. Lower modulus and tensile strength was seen for NR compounds when replacing carbon black with rice hull ash 8,9,29,30 and other biobased fillers 2,5 . This trend is mirrored in the storage modulus‐strain data.…”

“…Agro‐industrial residues 1 represent a large stock of underutilized renewable resources from various agricultural industries. Their utilization as fillers for plastics and elastomers (natural and synthetic) have been previously investigated 2–6 . Navas et al 3 examined the suitability of residues from the olive and wine industries for use in thermoplastic matrix composites.…”

A Review of Rubber Biocomposites Reinforced with Lignocellulosic Fillers

“…Lignocellulosic fillers are attracting considerable attention as alternative reinforcements in rubber composites due to their renewability, biodegradability, availability, high mechanical properties, low density and low cost [9,10]. For example, the annual production of mill wood residues in Canada for 2004 was estimated at 21.2 million bone-dry tons (BDt), of which 87% was used in applications such as pulp and paper, wood fuels, animal bedding, pellets, etc.…”

Preparation and characterization of non‐vulcanized natural rubber‐based cocoa pod husk composites

“…Among these compounding ingredients, fillers are the major additives used in natural rubber compounding and they play a dominant role in modifying the physical properties of base polymer 3 . Fillers are the second most important component of rubber composites by volume used 4 . These polymer additives play different roles either as diluents, process improvers, aesthetic improvers, or reinforcers 5 .…”