Abstract:As a kind of base polymer, polyisobutene (PIB) has many merits such as excellent oxidation resistance, good chemical stability and very low moisture permeability. However, the system of PIB is easy to creep, which limits its application in hot melt pressure-sensitive adhesives (HMPSAs). In this study, the structure stability, adhesion property and thermal performance of PIB HMPSA were successfully improved by introducing organic modified kaolin. Polydimethylsiloxane (PDMS)-Kaolin was obtained by grafting PDMS onto the surface of kaolin and using dimethyl sulfoxide (DMSO) for intercalating into the layers of grafted kaolin. The effect of organic modification process was characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), water contact angle measurement and Thermogravimetry (TG). The results of FTIR and TG manifested that PDMS molecular chains were grafted onto the surface of kaolin, besides, the XRD result showed that the interlayer spacing of kaolin was expanded from 0.7 nm to 1.1 nm which indicated DMSO molecular chains were intercalated into the galleries of kaolin and hydrogen bonds between the layers of kaolin were broken. After the modification process, the water contact angle of kaolin was increased from 10° to 114°, which demonstrated that the hydrophobicity of kaolin was increased significantly. PDMS-Kaolin/PIB HMPSAs were prepared by incorporating PDMS-Kaolin into PIB matrix using torque rheometer. The influences of PDMS-Kaolin mass fraction on properties of PIB HMPSA were investigated. Results showed that the structure stability, adhesion performance and thermal property of PIB HMPSA could be enhanced when the mass fraction of PDMS-Kaolin was above 0.5 %, adhesion performance reached maximum when the mass fraction was 1 % (The peak value of 180° peel strength was 0.659 N/mm) which was 11 % higher than that of pure PIB HMPSA. Continue adding PDMS-Kaolin, the peel strength of PDMS-Kaolin/PIB HMPSAs would decline sharply, when the mass fraction was 2 %, the peel strength declined to the minimum and the thermal stability achieved maximum.