Preparation of potassium oleate-kaolin/natural rubber composites by ball milling combined with gas-phase spray drying technology

In order to realize the high value-added utilization of natural clay materials in natural rubber composites, an environment-friendly animal glycerol potassium salt was introduced to modify kaolin, and the natural rubber with excellent performance were prepared by high-energy ball milling combined with gas-phase spray drying technology. The impact of the ball milling reduced the particle size and increased the specific surface area of kaolin, promoting the chemical modification of kaolin by potassium oleate. The gas-phase spray technology effectively broke the filler aggregates, and the high-temperature roller realized the instantaneous drying, reducing the oxidation and fracture of the rubber molecular chains. In this paper, the gas barrier properties, mechanical properties, anti-aging properties, dynamic mechanical properties and Payne effect of the composites were investigated. The FTIR, XPS and interfacial contact angle demonstrated the existence of a stable chemical bonding in the process of potassium oleate-modified kaolin, and the hydrophilicity of kaolin was reduced. Kaolin was uniformly and finely dispersed in the rubber matrix by spray drying technology. Compared with the traditional dry mixing, the composites prepared by the technology improved the gas barrier properties, processing properties, comprehensive mechanical properties, and the aging coefficient increased by 23.1%, and had excellent wet skid resistance and rolling resistance.