Preparation And Properties Of Thermoplastic Polyurethane Nanocomposites

Thermoplastic polyurethane(TPU)has excellent performance such as high resilience,strong resistance,good flexibility and outstanding biocompatibility.However,the mechanical strength and the heat resistance of TPU are poor.Moreover,TPU is easy to be softened and decomposed at high temperature,which leads to the sharp decline in mechanical properties.The long-term using temperature of TPU can not exceed 80 ?,and the short-term using temperature can not exceed 120 ?,which greatly limits the application of the materials.Nanomaterials generally have high melting point,high strength,wear resistance,good chemical stability and so on.In recent years,modifying TPU with nanomaterials has become one of the main methods to prepare high performance TPU nanocomposites.In this paper,MWCNTs@SiO2-KH560,MWCNTs@SiO2-TiO2-KH560,and SiO2@CeO2-KH560 were prepared,separately.Then,the TPU/nanomaterial composites were prepared by solution blending method.The prepared nanomaterials and nanocomposites were characterized by Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),transmission electron microscopy(TEM),scanning electron microscopy(SEM),thermogravimetric analysis(TGA)and electronic universal testing machine.The following research results had been made:1.The surface of the multi-walled carbon nanotubes(MWCNTs)was wrapped silica dioxide to prepare MWCNTs@SiO2 nanomaterials by hydrolysis method and then the nanomaterials were modified by KH560 to prepare MWCNTs@SiO2-KH560 nanomaterials.The modified nanomaterials were added into the TPU matrix to prepare TPU/MWCNTs@SiO2 nanocomposites by solution blending.The results showed that the elongation at break of TPU/MWCNTs@SiO2 nanocomposites achieved 1194%,and the tensile strength of TPU/MWCNTs@SiO2 nanocomposites reached 53 MPa when the content of MWCNTs@SiO2-KH560 nanomaterials is 2 wt.%in the nanocomposites.2.The surface of the MWCNTs was wrapped silica dioxide and titanium dioxide simultaneously to prepare the MWCNTs@SiO2-TiO2 nanomaterials using in-situ hydrolysis,the MWCNTs@SiO2-TiO2-KH560 nanomaterials were prepared by modified KH560 and the TPU nanocomposites were prepared using solution blending.The results showed that the mechanical properties and heat resistance of TPU/MWCNTs@SiO2-TiO2 composites were significantly improved when the content of nanomaterials was 2 wt.%.The elongation at break reached 1263%,the breaking strength reached a pressure of 45 MPa and the thermal decomposition temperature of these nanocomposites was 12? higher than that of pure TPU when the mass fraction of thermal decomposition was 10%.3.The SiO2@CeO2 nanomaterials were prepared using sillica dioxide coated with cerium dioxide via hydro-thermal method,the SiO2@CeO2-KH560 nanocomposites were achieved by KH560,and then the TPU/SiO2@CeO2 nanocomposites were prepared using a solution blending method.The results showed that the SiO2@CeO2-KH560 nanomaterials can improve the heat resistance of TPU nanocomposites.When the loading of SiO2@CeO2 nanomaterials was 2 wt.%in TPU nanocomposites,the tensile strength reached 46 MPa,which was increased by 31.4%compared with pure TPU.Meanwhile,elongation at break was increased by 66.3%compared with original pure TPU.In addition,the UV absorption capacity of TPU nanocomposites was significantly enhanced after introducing the SiO2@CeO2-KH560 nanomaterials.