溶剂对聚氨酯纳米纤维膜的影响

Solvent Effects on Polyurethane Nano Fiber Membrane

选用不同体积比的N,N-二甲基甲酰胺(DMF)和丙酮混合溶剂配制聚氨酯(PU)溶液,运用"Nanospider"纺丝技术制备聚氨酯纳米纤维膜。研究不同溶剂配比条件下PU溶液的电导率、粘度、高分子—溶剂相互作用参数和表面张力,从热力学、高分子溶液理论及高分子表面性质等方面对溶液进行分析。采用扫描电镜观察纳米纤维膜的表面形貌并对纳米纤维膜进行疏水性能和力学性能测试。结果表明:丙酮的加入显著改变混合溶液的溶解度参数、高分子与溶剂间相互作用参数、电导率、粘度等溶液性质。当DMF/丙酮体积比为33/67时获得的纳米纤维膜表面形貌较好;纳米纤维的直径随DMF体积减少而增大,DMF/丙酮体积比为67/33时纤维直径为(300±60)nm;纤维膜的水接触角随丙酮体积比的增加而逐渐增大,最大水接触角为112.52°;DMF/丙酮体积比为33/67时,力学性能最佳,应力和应变分别为8.6 MPa和309%。

N,N-dimethyl formamide(DMF)and acetone were mixed with different volume ratio as the solvent to prepare polyurethane(PU)nanofiber membrane by " Nanospider" spinning technique.The electrical conductivity,viscosity polymer-solvent interaction parameters and surface tension of PU solution under different volume ratio were investigated,and the solution was analyzed from thermodynamics,polymer solution theory and polymer surface property.The morphology of nanofiber membrane was observed with SEM,and hydrophobic property and mechanical property of nanofiber membrane were tested.The results show that the addition of acetone significantly changes solubility parameter,interaction parameters between polymer and solvent,conductivity,and viscosity properties of PU solution.When the volume ratio is 33/67,the nanofibers exhibit a good surface morphology.The average diameter of the nanofibers increases with the decrease of DMF content.The(300±60)nm fiber diameter can be obtained when the volume ration of DMF/acetone is 67/33.The water contact Angle of the nanofibers increases with the increase of acetone content,and the largest water contact angle is 112.52°.The best mechanical properties of nanofibers can be obtained when the volume ration of DMF/acetone is 33/67;the stress is 8.6 MPa and the strain is309%,respectively.