Torrefied agro‐industrial residue as filler in natural rubber compounds

Abstract

This study explored the feasibility of using torrefied biomass as a reinforcing filler in natural rubber compounds. Carbon black was then replaced with the torrefied biomass in elastomer formulations for concentrations varying from 0% to 100% (60 parts per hundred rubber or phr total). Their influence on the curing process, dynamic properties, and mechanical properties was investigated. Results were compared with the properties of vulcanizates containing solely carbon black fillers. Time to cure (t90) for compounds with torrefied biomass fillers increased, while filler‐filler interactions (ΔG') decreased, compared to carbon black controls. At low strains, the tan δ values of the torrefied fillers vulcanizates were similar to the controls. Incorporation of torrefied biomass into natural rubber decreased compound tensile strength and modulus but increased elongation. Replacement with torrefied fillers resulted in a weaker filler network in the matrix. Still, results showed that moderate substitution concentrations (~20 phr) could be feasible for some natural rubber applications.

Evidence of silane coupling in torrefied agro‐industrial residue‐filled poly(styrene‐co‐butadiene) rubber compounds

“…The rice hulls were torrefied and analyzed using methods described in a previous study. 11 Briefly, torrefaction of rice hulls was accomplished by placing 300 g of rice hulls in a 2 L steel vessel, which was then placed inside a Thermo Fisher (Waltham, MA) muffle furnace. The chamber of the furnace was flushed with nitrogen gas at a flow rate of approximately 2 L min À1 for 30 min to prevent combustion of the biomass during the heating process.…”

“…12 Upon torrefaction, the biomass was converted into a porous, carbonized solid, removing the water and partially decomposing the weak structural components, such as hemicellulose and, to an extent, cellulose. Increased hydrophobicity and microporosity (10-100 μm) 11 of the torrefied biomass improved filler interfacial adhesion with the NR matrix.…”

Surface Modified Nanocellulose and Its Reinforcement in Natural Rubber Matrix Nanocomposites: A Review

“…On the other hand, the modulus of TRH rubber composite showed the lowest modulus at 40:20 ratio before increasing gradually at 30:30 and 20:40 ratio. [ 25 ] Horsetail ( Equisetum Arvense ) Horsetail filler loading (10, 20, 30, 40 50 phr) Elongation at Break The elongation at break increases with increasing horsetail loading from 10 phr to 50 phr. Tensile Strength Tensile strength of rubber composite reinforced with horsetail show higher value than the pure natural rubber sample.…”

“…Torres et al [ 25 ] and Moonart and Utara [ 28 ] concluded that the curing time increased consistently with increasing filler loading. The increase in curing time suggested that a retardation effect occurred during the curing process.…”

“…Improvement in the mechanical properties of composites may result from increased adhesion of fibers to the polymer, and thus stronger interfacial interactions influencing the increase in cross-linking density. Torres et al [ 25 ] studied the effects of carbon black to torrefied fillers ratio on the tensile strength and modulus of natural rubber composite. The authors observed that the introduction of higher torrefied fillers loading reduced the tensile strength and modulus of the hybrid natural rubber composite.…”