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Effect of nanoparticles addition on the properties of polyurethane

Uppu, Vishanth
This research is aimed at analyzing the properties of polyurethane nanocomposites, before and after cryogenic exposure. Graphene and Cloisite 30B were chosen as filler materials and the main purpose of adding these fillers is to improve the barrier properties. Clay was added to the hard segment while the graphene was added to the soft segment of polyurethane matrix. The nanocomposites with single-additive and with dual-additives were prepared by incorporating different concentrations of graphene and clay into polyurethane. These samples were then characterized using DSC, DMA and SEM. Instron machine was utilized to measure the tensile properties. The focus was on comparing the influence of using one-additive and two-additives on polyurethane and investigating the degradation of the nanocomposites due to initial cryogenic exposure. The results indicated that the uniform dispersion of the fillers led to an increase in glass transition temperature, stiffness and tensile modulus of the composites while the agglomeration at higher loading decreased these properties. When exposed to cryogenic temperatures, micro-cracks were seen in samples with higher loading of clay while there was no considerable change noticed in all the properties denoting the suitability of polyurethane composites for cryogenic applications. To assess the gas permeability characteristics of the composites an instrument was designed adhering to standard test method documented in ASTM D-1434(15).