Thermo-Mechanical Investigation of Nanoreinforcements Doped Elastomeric Nanocomposite Thermal Insulations

Abstract

The dissertation reports the efficiency of the nanofillers to attenuate thermal insulation, thermal transition, thermal stability, and mechanical characteristics of the elastomeric nanocomposites. Twenty eight diverse elastomeric systems have been used with functionalized multiwall carbon nanotubes (FMWCNTs)/nanokaolinite (FNK) and elastomeric matrices including ethylene propylene monomer rubber (EPDM), styrene butadiene rubber (SBR), silicon rubber (SR), acrylonitrile butadiene rubber (NBR) to fabricate polymer nanocomposites suitable for multiple applications according to the thermo-mechanical character. The nano-incorporations were functionalized using 3aminopropyl trimethoxy silane to improve their dispersibility and compatibility with the host polymer matrices. Activated nanoclay with average particle size 3nm was synthesized adopting novel economical and easy methodology. Various concentrations of activated nanoreinforcements have been impregnated in the elastomeric matrices at specific timetemperature and rolling velocity conditions. Elastomeric composite specimens in particular mold geometries were cured on the hot isostatic press at specific temperature and pressure. Functionalization and crystallographic study of the incorporated nanofiller were executed using on Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. The fabricated composite specimens were put into test for thermal conductivity/impedance, scanning electron microscopic, differential scanning calorimetric, thermal decomposition, differential thermal analysis, Shore A hardness and uniaxial tensile tests to elucidate the effect of functionalized nanofillers on the thermal and mechanical characteristics of the polymer nanocomposites. Thermo-mechanical properties have been remarkably influenced with increasing the functionalized nanoclay/nanotubes concentration in the host elastomeric matrices. High thermal stability, heat quenching capability, low thermal conductivity, high mechanical strength, and efficient reinforcement–matrix adhesion are identified as the most prominent factors for enhanced thermal insulation performance of elastomeric nanocomposites. The least value of thermal conductivity (0.009W/m.K), utmost thermal impedance (5.12m.K/W), and highest ultimate tensile strength (8.45MPa) were scrutinized for 30wt% FNK impregnated NBR nanocomposite. The uppermost thermal stability, lowest glass transition and crystallization temperatures were observed for 1wt% FMWCNTs incorporated SR composite. In view of overall performance, FMWCNTs and nanokaolinite impregnated NBR and EPDM elastomeric nanocomposites are demonstrated better compared to other fabricated composite systems regarding all performed thermomechanical aspects. The novelty of this research work resides in fabrication and thermo-mechanical study of new elastomeric composite formulations using functionalized nanofillers. Thermal transport study and differential thermal analysis of the fabricated polymer nanocomposites are also added values to the present scientific literature on elastomeric nanocomposites. The highest thermal insulation character was observed for the FNK/NBR systems compared to the contemporary available data on the elastomeric nanocomposites. The designer can select a suitable combination of elastomeric nanocomposite for the situation at hand using the thermal transport/stability/transition temperatures, specific enthalpies and mechanical investigation data provided in consolidated form at the end of the dissertation. Fast and economical route to synthesized functionalized nanokaolin with average particle size less than 5nm is also introduced novelty.