Synthesis Of Low Fluoride Thermoplastic Polyurethane Biomaterials With High-Performance

Thermoplastic polyurethane elastomer (TPU) was widely used as biomedical materials because of its excellent mechanical property and biocompatibility. However, when it was implanted into human body in long-term, it may be hydrolysed and aged. The result shows that the biocompatibility of TPU can not suit the requirements of long-term implantation in the human body. Therefore, TPU needs to be modified, and hydrophobic modification on the surface is a good method. Due to the high electronegativity, smaller atomic radius and strong volume rejection effect of fluorine atom, fluorinated thermoplastic polyurethane (FTPU) elastomers combine some virtues of both TPU and fluorinated polymer, such as high elasticity, strength, and wear resistance. What’s more, FTPU has good blood compatibility and cell compatibility. In this paper, fluorine element was introduced into TPU structure via fluoride polyols in order to meet the good biocompatibility and mechanical performance of biomedical polyurethane requirements. The relationships of surface composition and properties, micro morphology, micro phase separation structure and biocompatibility of FTPU elastomers were investigated in detail.Firstly, duo to low surface energy of fluorine carbon chain, polyether polyols containing fluorine in main chain as soft segment were used to preparefluorinated thermoplastic polyurethane (FTPU) elastomers via one-step bulk polymerization method. A series of characterizations show that the the surface properties and biocompatibility of polyurethane were obvious increased by introducing fluorine element, but its mechanical properties decreased. Morepver, TPU elastomer need to contain high fluorine content in order to get better performance because fluorine carbon chain on main chain can not easily migrate, which increased the cost of production.Secondly, in order to decrease the high cost of production, a side chain containing fluorine polyols was successfully synthesized by cationic ring-opening polymerization method, and characterized properties by the infrared spectra. Through a series of optimized experiment conditions, the excellent property of side chain containing fluorine polyols was prepared. This will lay the foundation for preparation of side chain fluorinated thermoplastic polyurethane elastomer.Finally, the side chain fluorinated thermoplastic polyurethane elastomer was synthesized by one-step bulk polymerization method and two step method with the aid of fluoride side chain high sport ability. Thereinto, side chain fluorinated polyether and PTMEG resin serve as the soft segments, and diphenyl methane diisocyanate (MDI) and 1,4-butyl glycol (BDO) work as hard segment. The composition, structure, surface properties, biological properties and mechanical properties were studied. All the results show that side chain FTPU elastomer has excellent biocompatibility and well mechanical performance under low fluorine content.