聚氨酯/石墨烯复合纤维的制备及其发泡性能研究

以热塑性聚氨酯(TPU)、单层纳米石墨烯(GR)通过溶液与熔融共混并用的方法制备TPU/GR共混物,利用不同牵引速度纺丝制得不同直径的TPU/GR复合纤维,对其进行超临界二氧化碳微孔发泡,制得发泡TPU/GR复合纤维,探究了GR在TPU中的分散性,纤维尺寸和GR含量对发泡TPU/GR复合纤维泡孔结构及力学性能的影响。结果表明:GR在TPU体系中具有良好的分散形态及较高的二氧化碳气体阻隔性能;当发泡TPU/GR复合纤维直径为200μm时,随着GR含量的增加,纤维的发泡面积逐渐变大,泡孔直径呈现先减少后增加的趋势;对于直径为500μm的发泡TPU/GR复合纤维,随着GR含量的增加,纤维的泡孔直径逐渐变小,泡孔密度逐渐增加,即当加入质量分数为5%的GR,纤维泡孔直径由原来未加GR时的3. 78μm降低至1. 97μm,泡孔密度由原来的未加GR时4. 93×10~9cells/cm^3增加至2. 42×10¹⁰cells/cm^3。

Preparation and foaming properties of polyurethane/graphene composite fibers

Thermoplastic polyurethane(TPU)/graphene(GR)composites were prepared from TPU and GR by a solution and melt blending,from which TPU/GR composite fibers with different diameter were fabricated at different drawing rate.Subsequently,foamed TPU/GR composite fibers were prepared by a batch foaming process using supercritical carbon dioxide as a foaming agent.The effects of the dispersity of GR in TPU,fiber dimension and GR content on the microcellular structure and mechanical properties of foamed TPU/GR composite fiber were studied.The results showed that GR sheets had a favorable dispersion morphology in TPU matrix and a relatively high carbon dioxide gas barrier property;the foaming area of the fiber was gradually increased and the cell diameter was decreased and then increased with the increase of GR when the foamed TPU/GR composite fiber was 200μm in diameter;the cell diameter was gradually decreased and the cell density was gradually increased with the increase of GR when the foamed TPU/GR composite fiber was 500μm in diameter;and the cell diameter of the fiber was decreased from 3.78μm to 1.97μm and the cell density was increased from 4.93×10^9 cells/cm^3 to 2.42×10^10 cells/cm^3 when 5%GR was added by the mass fraction.