Preparation and application of modified organo-kaolinite by microwave-assisted irradiation

Abstract From the aspect of the modern approach, it is necessary to increase the intercalation efficiency for the objective of widespread market application of kaolinite. The submitted article deals with the microwave-assisted modification of kaolinite (Kaol). Using potassium acetate (KAc) solution and dimethyl sulphoxide (DMSO), Kaol was treated chemically by a microwave radiation at different time intervals at a set constant temperature. Different techniques, such as X-ray diffraction patterns analysis (XRD), Fourier transformed infrared spectroscopy (FT-IR) spectroscopy, thermogravimetry/ differential scanning calorimetry (TG/DSC), and scanning electron microscopy (SEM) were used to characterize Kaol and modified kaolinite samples. The modification was observed after microwave radiation was applied for a short time (30 min). Finally, for the supplementation of the results, the model rubber compounds, filled with Kaol, modified Kaol-KAc and Kaol-DMSO samples in the amount of 10 phr (parts per hundred rubber), were prepared. The effect of modified kaolinite on the curing characteristics and mechanical properties in sulphur-cured natural rubber (NR) compounds was investigated. Partial substitution of carbon black with Kaol-DMSO led to the lower minimum torque and the acceleration of the crosslinking reaction. Moreover, the NR vulcanizates containing Kaol-DMSO showed higher tensile strength and hardness along with high maximum torque that are indicators of the reinforcing effect of the modified kaolinite.