Thermal destruction of carbon black network structure in natural rubber vulcanizate

Biochar from waste agriculture as reinforcement filer for styrene/butadiene rubber

Carbon black (CB), obtained by incomplete combustion of heavy petroleum products, is the most important filler used to improve the properties of various rubber composites. Its production process causes very serious environmental impacts in addition to its dependence on nonrenewable resources. Therefore, the trend has been to use eco‐friendly alternative materials that reduce the pollution associated with the CB production process and at the same time achieve the required mechanical properties of rubber composites. Biochar, a carbon‐rich solid product, could fulfill this role. It can be obtained by pyrolysis of organic matter such as agricultural waste in the absence of air at temperatures of 400–600°C. Herein, biochar was used in different ratios with CB to investigate its effect on the mechanical properties of styrene/butadiene rubber. The chemical composition of biochar and CB was investigated using a scanning electron microscopy and X‐ray fluorescence. In addition, the thermal properties, tensile strength, elongation at break, as well as thermo‐oxidative aging of the prepared rubber were studied. The tensile strength for styrene/butadiene rubber (SBR) composites containing 100% CB was 14.9 MPa, which decreases by adding biochar where it becomes 13.5, 11.2, 9.5, and 6.9 for SBR composites containing 25%, 50%, 75%, and 100% biochar, respectively. Furthermore, the vulcanized sample with 25% biochar (E2) shows higher retained tensile strength values than that containing 100% CB (E1) with increasing the aging time.

Imaging the strain induced carbon black filler network structure breakage with nano X-ray tomography

The 3D dispersion and breakage of CB aggregates in the natural rubber matrix are obtained by TXM at stain 3.