Fabrication And Performance Of Rare Earth Modified Thermoplastic Polyurethane Elastomer

Thermoplastic polyurethane elastomer (TPU) is a kind of block copolymer consisting of hard and soft segments with excellent high strength, high wear resistance and high elasticity. With the development of society, TPU has been applied to clothing, aerospace, biomedical and other fields, which also put forward higher requirements on TPU about its mechanical, thermal, surface, biological properties. Taking into account about the characteristics of rare earth’s special 4f empty orbits structure, can easily formed coordination bond with strong polar groups; highly active, easy coordination of nano rare earths was choose as modifier to prepared the nanosized rare earth oxide modified TPU elastomers.Firstly, nanometer rare earth oxides were prepared via ultrasonic assisted precipitation method, then was introduced into TPU synthesis system and dispersed by stir and ultrasonic means. Furthermore, nanosized rare earth modified TPU elastomer was obtained via one-step in situ bulk polymerization technique. This method has advantages of simple technology, experimental control and green environmental protection.Secondly, the effect of nanosized rare earth on TPU’s chemical structure, microphase separation and crystallization were investigated. SEM observation showed that rare earth oxide nanoparticles uniformly dispersed in the TPU matrix and promote the microphase separation of TPU. FTIR results showed that the nano rare earths can interact with TPU and affects accelerate microphase separation. XRD results show that TPU hard segment crystal diffraction peak shift due to the introduction of nano rare earth. Further, the mechanism of nano rare earth with TPU was preliminary discussion.Finally, the influences of nano rare earth on mechanical, thermal, surface and biological properties of TPU were also investigated. When the introduction of nano Nd2O3 and nano La2O3 amounts was 0.5 wt%, the tensile strength and elongation at break of TPU was increased by 89% and 38.8%. When 0.7 wt% of nano CeO2 and La2O3 was introduced of the initial decomposition temperature of TPU were raised 18 and 24 ℃, respectively. Moreover, as the introduction of nano rare earths, the surface hydrophobicity property of TPU was obviously improved and the surface free energy was reduced, and the blood compatibility and biocompatibility are improved significantly.