Preparation of silica/natural rubber composites by foaming predispersion combined with gas‐phase‐assisted spray technology

Abstract

This study proposes that the foaming pre‐dispersion technology is combined with the gas‐phase‐assisted spray technology, and a foaming agent potassium oleate is introduced. The volume expansion power generated by the bubbles promotes the dispersion of the filler. The uniformity of foaming promotes the chemical bridging of potassium oleate between rubber and silica. Then, with a large velocity difference between the compressed air and the emulsion, the gas‐phase‐assisted spray gun refines the emulsion and breaks the filler aggregates. Next, the atomized droplets splash on the surface of the high‐temperature roller, and then deposit on it to achieve instant drying, which reduces the loss of non‐rubber components, thereby improving the preparation efficiency and comprehensive properties of masterbatch. The Payne effect of the composite prepared by the FGS technology is weaker. The tensile strength, elongation at break, and tensile product of the vulcanizate prepared by the FGS technology with 7 phr PO have increased by 9%, 5%, and 15%, respectively, and the aging coefficient is 23% higher than that of the dry mixing.

Wet continuous mixing technology and extrusion rheological properties of carbon black/natural rubber composites

“…The flocculated NRL has better flexibility than the dry rubber used in the DM, and the shear action of the double‐rotor also weakens the entanglement between the rubber molecular chains, thereby improving the rebound rate. In combination with the extrusion rheological properties, the FECM technology increases the filler‐rubber network, the extrusion swell ratio and the dependence of the shear rate on temperature are relatively small, indicating that NR composites have good resistance to deformation 7,43,44 . The abrasion resistance is related to filler‐matrix interaction and the dispersion of fillers 45 .…”

“…In combination with the extrusion rheological properties, the FECM technology increases the filler-rubber network, the extrusion swell ratio and the dependence of the shear rate on temperature are relatively small, indicating that NR composites have good resistance to deformation. 7,43,44 The abrasion resistance is related to filler-matrix interaction and the dispersion of fillers. 45 Compared with the DM process, the abrasion volume of the composites prepared by the FEM process and the FECM process is reduced by 12% and 9%, respectively, and the abrasion resistance is improved.…”

“…However, the aggregation of polar fillers is relatively serious during dry mixing, with rapid heat generation, easy scorching, high energy consumption, and serious dust pollution 5 . Wet mixing is the process in which the filler is made into water dispersion, fully mixed with latex in the liquid state, then flocculated, dewatered, and dried to finally prepare the rubber masterbatch 6–8 . Wet mixing not only significantly improves the dispersion of reinforcing fillers, and prepares high‐performance rubber compounds with high filler content, but also reduces energy consumption and adapts to the development of green and energy conservation 9,10 .…”

“…5 Wet mixing is the process in which the filler is made into water dispersion, fully mixed with latex in the liquid state, then flocculated, dewatered, and dried to finally prepare the rubber masterbatch. [6][7][8] Wet mixing not only significantly improves the dispersion of reinforcing fillers, and prepares high-performance rubber compounds with high filler content, but also reduces energy consumption and adapts to the development of green and energy conservation. 9,10 Xuan et al 11 compared the mixing power curves of rubber compounds by dry mixing and wet mixing, and the results showed that compared with dry mixing, wet mixing reduced the energy consumption by 30%, improved the dispersion of fillers and the mechanical properties of composites.…”