Silane coupling agent γ-aminopropyltriethoxysilane-modified nanoparticles/polyurethane elastomer nanocomposites

Polyurethanes (PUs) have been extensively applied in commercial elastomeric fields due to their highly reversible elastomeric responses. However, it is still very important to improve their thermal resistance to expand engineering applications. In this respect, by physically mixing of polyurethane elastomer (PUE) with SiO2, TiO2, and Al2O3 nanoparticles as reinforcing agents and gamma-aminopropyltriethoxysilane (KH550) as surface modification agent, three types of modified PUE nanocomposites were studied. The resultant composites were investigated by mechanical testing, SEM, TG, and DSC analyses. The polyurethane sample reinforced with nanoparticles modified with 1.00% (by weight) KH550 exhibited the highest tensile characteristic. Besides, these nanocomposites with nanofiller contents of 6.00%, 4.00%, and 8.00% (by weight) for SiO2, TiO2, and Al2O3 showed the best tensile properties, respectively, as compared to those unfilled counterparts. Especially, the Al2O3/PUE composites possessed a tensile strength as high as 20.9 MPa, and a maximum elongation at break of 1759%. SEM images showed that the modified nanofillers presented better dispersion capacity throughout the matrix. The results of DSC tests demonstrated that the inclusion of KH550-modified inorganic additives made no appreciable effect on glass transition temperature of PUE composites. In addition, TG curves showed that the thermal stability of Al2O3/PUE nanocomposite increased to 278 celcius. These events revealed that an effective surface modification of nanoparticles was beneficial for the improvement of tensile properties and thermal stability of nanocomposites, owing to both the excellent dispersion of nanofillers and the improved compatibility between nanoparticles and polyurethane matrix. This work may offer a facile strategy for preparing a polyurethane elastomer with enhanced tensile properties and thermal stability that can find an application, e.g., in damping apparatus.