选用聚氨酯常用原料甲苯-2,4-二异氰酸酯 (TDI)对碳纳米管 (CNT)进行表面改性,制得异氰酸酯功能化CNT (CNT-NCO);再经原位聚合使CNT-NCO参与聚氨酯基体聚合反应,制备CNT-NCO/热塑性聚氨酯弹性体 (TPU)复合材料。采用FT-IR、TG、DSC、XRD、SEM、维卡软化温度和拉力试验机等测试手段,表征分析了CNT-NCO的表面结构及其含量对CNT-NCO/TPU复合材料结构与性能的影响。结果表明,TDI成功对CNT进行了表面改性;CNT-NCO的加入降低了TPU微相的分离程度,其异相成核作用提高了TPU硬段相的结晶性能;CNT-NCO/TPU复合材料耐热性能和力学性能明显提高,与纯TPU相比,当CNT-NCO含量为0.1% (wt,质量分数)时,复合材料维卡软化温度提高32℃,拉伸强度提高约15MPa,断裂伸长率提高约21%。
The isocyanate functionalized carbon nanotubes (CNT-NCO) were synthesized with toluene-2,4-diisocyanate (TDI),which was one common monomer for synthesizing polyurethane,and further polymerized with the other raw materials of thermoplastic polyurethane elastomers (TPU) via in situ polymerization to prepare a series of CNT-NCO/TPU composites with different CNT-NCO contents.The structure of CNT-NCO was characterized and the influences of the dosage of CNT-NCO on the structure and properties of CNT-NCO/TPU were studied by FT-IR,TG,DSC,XRD,SEM,the vicat softening temperature and the mechanical property.The results demonstrated that TDI successfully grafted onto CNT.For the TPU matrix,the incorporation of CNT-NCO can decrease the extent of microphase separation and improved the crystallinity of hard segment as a heterogeneous nucleation agent.In comparison with the pristine TPU,the thermal properties and mechanical properties of CNT-NCO/TPU were enhanced markedly.When the mass fraction of CNT-NCO was 0.1wt%,the vicat softening temperature raised by 32℃,the tensile strength increased almost 15MPa,and the elongation at break increased about 21%.
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