Shape Memory Performance in Composites with the addition of TiO2

Abstract

Shape memory polymers (SMPs) are smart materials that can change their macroscopic properties such as shape and colour with the effect of external stimuli and return to their original state when the stimulating effect is removed. Factors such as heat, light, magnetic field, electric field, and pH are accepted as external stimuli. There are basically two requirements for obtaining the shape memory effect (SME). The first is that the polymer has a stable network structure. The other is that the polymer has key points that allow it to change shape under certain stimulating effect and to reinstatement when the effect is removed. Shape memory polymers are advantageous in that they are light, low density, easy to produce, have high biodegradability and easily adaptable glass transition temperature. However, there are some difficulties that prevent the use of these materials in practical applications. One of the main disadvantages of shape memory polymer applications is their relatively low mechanical properties, and particularly recovery stress. In order to overcome such disadvantages, significant advances have been made by incorporating various reinforcing materials into the shape memory polymer. Therefore, in this study different proportions of TiO2 nanomaterial were added to the Poly (Vinyl Alcohol) (PVA) matrix in order to improve its shape memory property. Thermal, spectral, chemical, and structural characterizations of the obtained composites were made using DSC/TGA, FT-IR, SEM/EDS, and XRD analysis methods. In addition, shape memory performances were determined by the bending test.