热塑性聚氨酯/石墨烯纳米复合材料的制备及性能研究

Preparation and properties of thermoplastic polyurethane/graphene nanocomposites

采用热剥离法和甲苯二异氰酸酯(TDI)改性制备了功能化氧化石墨烯(iGO),并以iGO作为填料制备了热塑性聚氨酯/石墨烯(TPU/iGO)纳米复合材料。采用扫描电镜(SEM)对GO和iGO进行了微观形貌研究;采用XRD衍射仪、拉曼光谱仪和傅里叶红外光谱仪等对复合材料的结构进行了研究;采用精密介电频潜仪测定了复合材料的介电常数和介质损耗因数。结果表明,TDI对iGO材料的插层改性,增大了石墨烯的层间距;TPU-2.0%iGO纳米复合材料的拉曼光谱与纯iGO材料更加相似,而其红外光谱与纯TPU材料更加相似;iGO的掺入,有效提高了复合材料的抗拉强度,当iGO添加量为0.5%(体积分数)时,TPU/iGO纳米复合材料的抗拉强度达到最大,为54.6MPa,比纯TPU基体材料提高了20.5%;在频率为1000 Hz时,TPU-2.0%iGO纳米复合材料薄膜的介电常数最高可以达到308.2,同时介电损耗却很低,在频率>1000 Hz时,其介电损耗在0.2以下。因此,TPU/iGO纳米复合材料可作为有效的EMI屏蔽和ESD材料。

Functionalized graphene oxide(iGO)is prepared by thermal exfoliation and toluene diisocyanate(TDI)modification,and thermoplastic polyurethane/graphene(TPU/iGO)nanocomposites are prepared by using iGO as filler.The morphology of GO and iGO are studied by scanning electron microscope(SEM).The structure of the composite is studied by XRD,Raman and FT-IR.The dielectric constant and dielectric loss factor of the composites are measured by a precise dielectric frequency submergence meter.The results show that the intercalation modification of iGO by TDI increases the interlayer spacing of graphene.The Raman spectra of TPU-2.0vol%iGO nanocomposites are more similar to pure iGO materials,while the infrared spectra of TPU-2.0vol%iGO nanocomposites are more similar to pure TPU materials.The tensile strength of the composite is improved by the addition of iGO.When the content of iGO is 0.5vol%,the tensile strength of TPU/iGO nanocomposites reaches the maximum,which is 54.6 MPa,20.5%higher than that of pure TPU matrix.The highest dielectric constant of TPU-2.0vol%iGO nanocomposite film could reach 308.2 at 1000 Hz,but the dielectric loss is very low,and when the frequency is higher than 1000 Hz,the dielectric loss is less than 0.2.Therefore,TPU/iGO nanocomposites can be used as effective EMI shielding and ESD materials.