Nanocomposites based on thermoplastic polyurethane, millable polyurethane and organoclay: Effect of matrix composition and dynamic vulcanization

Abstract

Dynamically vulcanized thermoplastic polyurethane (TPU)/millable polyurethane (MPU) blend nanocomposites, simple TPU/MPU blend nanocomposite, and TPU nanocomposite with 3 parts per hundred (phr) of organoclay were melt compounded in an internal mixer. Interfacial interactions between the organoclay and polyurethanes were examined by Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscope analysis, which revealed that the dispersion of organoclays significantly improved with increasing TPU content in the TPU/MPU blends and dynamic vulcanization process. Tensile test and dynamic mechanical analysis showed that the mechanical properties are improved with the TPU content in the TPU/MPU blends and dynamic vulcanization process. Both hardness and tension set of the samples decreased with increasing MPU content in the TPU/MPU blends. Thermal stability determined by thermo-gravimetric analysis revealed that it increased with increase in TPU concentration in the samples. Differential scanning calorimetry study showed that the glass transition temperature (T g ), melting temperature (T m ), and melt crystallization temperature (T c ) of the samples were significantly affected by the blend composition and dynamic vulcanization. Dynamic melt rheology of the nanocomposite samples in the molten state revealed a pseudo solid-like behavior as well as an enhanced shear thinning behavior, and the variation of the rheological properties are well correlated with blend compositions and morphology of the nanocomposites.

Nanocomposites based on thermoplastic polyurethane, millable polyurethane, and organoclay: effect of organoclay content

“…Mixing of samples was carried out at 180 C temperature for 6 min at 60 r/mim, which is optimized in our previous work by Taguchi methodology. 11,12 TPU and Cloisite 30B (C30B) were dried overnight in a vacuum oven at 101.60 kPa and 50 C temperature to remove water before use. Sheet specimens of about 1-2 mm thickness were prepared by compression molding and standard specimens for testing were punched out using a cutter.…”

Improved covulcanization and dynamic properties of millable polyurethane elastomer/natural rubber blends: Thermal pretreatment

“…In a study of MPU blended with low density polyethylene (LDPE), the thermal shrinkage behavior and mechanical response of MPU/LDPE were improved by implementing interchain crosslinking between the two components 7 . Barick 8 investigated the effect of matrix composition and dynamic vulcanization on the property MPU/thermoplastic polyurethane elastomer (TPU)/organoclay blends. By optimizing processing parameters, including mixing temperature, mixing time and rotor speed, a balance of good performance, product cost and reliability of the blend was obtained.…”