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Sound and vibration damping properties of composites based on styrene-butadiene copolymer

Development of (nano)materials with new properties and structures is essential for further progress in modern technologies and fields of research and engineering. Aim of this work was to develop materials for application in the field of vibration and sound damping. Dynamic-mechanical and damping properties of polymer blends, comprised of PS-GP (general purpose polystyrene) and SHBC (styrene–hydrogenated butadiene copolymer), were investigated. Series of polymer blends with various PS/SHBC ratios were prepared by mixing of solutions of single polymers in toluene. Furthermore, composites with various weight fractions of multiwall carbon nanotubes (MWCNT) as filler were prepared by solution mixing, using high speed stirrer and ultrasonic bath. Mixtures were cast in PTFE molds and dried at 60 °C. Obtained materials were characterized by dynamic-mechanical analysis (DMA) in order to determine glass transition temperature and primary viscoelastic functions (storage modulus, loss modulus, tan delta) and by differential scanning calorimetry (DSC) in order to confirm thermal phase transitions. Modified dynamic-mechanical analysis according to ISO 6721 (Oberst's method) was used to determine loss factor of material, which is a direct measure of capability of material to absorb energy of vibration and sound. Scanning electron microscopy was utilized to observe morphology of prepared polymer blends and composites. DMA results show glass transition temperature in a range between -20 °C and -10 °C for all prepared materials. Results of the Oberst's method show that maximum values of loss factor are obtained at temperature around -10 °C ; as expected, energy absorption capability reaches its maximum around glass transition temperature of material. Also, it has been determined that with increase of the MWCNT content in composite, loss factor increases as well.

sound damping; styrene-butadiene copolymer

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