Chlorinated butyl rubber/two-step modified montmorillonite nanocomposites: Mechanical and damping properties

Montmorillonite (MMT) was modified by ultrasound and castor oil quaternary ammonium salt intercalation method to prepare a new type of organic montmorillonite (OMMT). The surface structure, particle morphology, interlayer distance, and thermal behavior of the samples obtained were characterized. The modified OMMT was then added to chlorinated butyl rubber (CIIR) by mechanical blending, and a composite material with excellent damping properties was obtained. The mechanical experiment results of CUR nanocomposites showed that the addition of OMMT improved their tensile strength, hardness, and stress relaxation rate. Compared with pure CUR, when the content of OMMT was 5 phr (part per hundred of rubber), the tensile strength of the nanocomposite was increased by 677% and the elongation at break was also increased by 105.4%. The enhancement of this performance was mainly due to the dispersion of the nanosheets in CIIR rubber and the chemical interaction between the organoclay and the polymer matrix, which was confirmed by morphology and spectral analysis. OMMT also endowed a positive effect on the damping properties of CIIR nanocomposites. After adding 5 phr of OMMT, the nanocomposite owned the best damping performance, and the damping factor, tan delta(max) was 37.9% higher than that of pure CUR. Therefore, the good damping and mechanical properties of these CIIR nanocomposites provided some novel and promising methods for preparing high-damping rubber in a wide temperature range. (C) 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Automated summary

Montmorillonite was modified and used as an additive in chlorinated butyl rubber to improve its mechanical and damping properties. The modified montmorillonite showed enhanced tensile strength and stress relaxation rate in the rubber composite.