Preparation Of Polyurethane / POSS Nanofiber Membrane And Study On Blood Compatibility

Polyurethane was synthesized by the reaction of Toluene 2,4-diisocyanate and poly tetrahydrofuran (PTMG) as a class of block copolymer with repeat unit of polyether polyols and urethane, then the molecular weight of the polymer was increased by adding chain extender 1,4-butanediol (BDO). The hard segment is composed of isocyanate and chain extender, and the soft segments is usually a polyol. PU,1% POSS-PU and 2% POSS-PU were synthesized by the addition of Owt%, 1wt%,2wt% TriSilanollsobutyl POSS respectively. We prepared the Owt%, 1wt% and 2wt% POSS-PU electrospinning nanofibers by electrospinning technique. Analysis of the fiber morphology was studied by scanning electron microscopy, we obtained the optimum spinning conditions:Concentration of POSS-PU is 12%, the spinning voltage is 20 kv, receiving distance is 20 cm, the extrusion speed is 0.8 mL/h. The contact of lwt% and 2wt%POSS-PU electrospun fibers membrane increased 12.5° and 24.3°. The results of platelet adsorption tests showed that the POSS-PU electrospun fibers membrane significantly inhibited platelet adhesion. BSA protein adsorption test proved that the PU nano fiber membrane modified by POSS has the characteristics of resistance protein adsorption, the effect of resisting protein adsorption was more obvious with the increase of POSS content. Hemolysis test analysis of POSS-PU electrospun fibers membrane can reduce the rate of hemolysis. The nanofiber membrane can effectively inhibit the growth of bacteria after adding POSS into the PU. TG test showed that the initial degradation temperature of the polyurethane decreased gradually with the increase of POSS content. The final residual rate of the fibers membrane is increased after the adding POSS into the PU. The mechanical property test results show that the tensile strength and elongation at break of the electrospun fibers membrane after adding POSS.Then we mixed with nano silver in pure PU and 1% POSS-PU spinning solution. Analysis of the fiber morphology was studied by scanning electron microscopy, we obtained the optimum spinning conditions:Nano silver content was 0.5wt%, mixed solution concentration is 15 kv, receiving distance is 15 cm, the extrusion speed is 0.6 mL/h. Water contact angle test results showed that the water contact angle of pure PU and nano silver blend electrospun fibers membrane increased by 20.9° compared to PU electrospun fibers membrane, the water contact angle of the 1% POSS-PU and nano silver blend electrospun fibers membrane was increased by 13.1° compared with the 1% POSS-PU electrospun fibers membrane. Combination of hydrophobic POSS and nano silver maximized the water contact angle of electrospun fibers membrane. The antibacterial test results show that the electrospun fibers membrane can kill bacteria after adding nano silver, POSS and nano Ag have a compound antibacterial effect for the electrospun fibers membrane. Mechanical properties testing results show that the tensile strength of electrospun fibers membrane was enhanced, but the elongation at break decreased after adding the nano Ag. On the basis of these results, we can assert that POSS-PU electrospun fibers membrane is a promising biomaterial.