Preparation and shape memory properties of TiO2/PLCL biodegradable polymer nanocomposites

The preparation of TiO2/poly(L-lactide-co-ɛ-caprolactone) (PLCL) nanocomposites and their properties were reported. TiO2 nanoparticles were surface modified by ring-opening polymerization of ɛ-caprolactone (ɛ-CL). The resulting poly(ɛ-caprolactone)-grafted TiO2 (g-TiO2) was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). The g-TiO2 can be uniformly dispersed in chloroform and the g-TiO2/PLCL nanocomposites were successfully fabricated through solvent-casting method. The effects of the content of g-TiO2 nanoparticles on tensile properties and shape memory properties were investigated. A significant improvement in the tensile properties of the 5% g-TiO2/PLCL mass fraction nanocomposite is obtained: an increase of 113% in the tensile strength and an increase of 11% in the elongation at break over pure PLCL polymer. The g-TiO2/PLCL nanocomposites with a certain amount of g-TiO2 content have better shape memory properties than pure PLCL polymer. The g-TiO2 nanoparticles play an additional physical crosslinks which are contributed to improvement of the shape memory properties.