Thermo-mechanical properties of polyurethane modified with graphite oxide and carbon nanotube particles

Abstract

The aim of the proposed paper is to synthesize graphite oxide (GO) and use it in combination with carbon nanotubes (CNT) for the preparation of polyurethane (PU) composites. We fabricated composites with CNT/GO content of 0.05, 0.1, 0.3 wt.% with the use of ultrasonic treatment and tested their thermo-mechanical properties. Thermo-mechanical analysis (TMA) and dynamic mechanical analysis (DMA) measurements for CNT/GO composites were compared with the unfilled PU. Thermo-mechanical characteristics of storage moduli and loss moduli for CNT/GO nanocomposite were improved in comparison to the unfilled PU. The introduction of CNT/GO to the PU matrix creates strong bonding with the matrix and leads to the decrease of the glass transition temperature, new solid-solid phase transitions of polymer in the glass state. Dilatometric curves testified the remarkable changes in the glass transition of the polymer after the introduction of CNT/GO hybrid filler. Thermal expansion coefficient was calculated from the curve slopes and expressed continuously increasing expansion rate for CNT/GO composite. The measured characteristics were directly dependent from the filler content in the composite and the operated temperature.