功能化氮化硼纳米片的制备及在导热聚氨酯复合材料中的应用

Preparation of Functionalized Boron Nitride Nanosheets and Their Application in Thermally Conductive Composites on the Matrix of Polyurethane

采用机械砂磨剥离与非共价键表面修饰相结合的方法,制备了左旋赖氨酸(Lys)功能化接枝氮化硼纳米片(Lys@BNNS),将其作为填料通过液相混合和热压方式得到热塑性聚氨酯(TPU)复合材料。采用红外光谱、热失重分析仪、X射线衍射仪、X射线光电子能谱仪、扫描电子显微镜及透射电子显微镜表征了Lys@BNNS的结构与形貌特征;采用导热仪和红外热成像仪探讨了不同填料含量对复合材料导热性能和散热速率的影响。当填料质量分数达到5%时,Lys@BNNS/TPU复合材料的热导率比纯TPU增加了160%,散热速率提高了100 s。这对于提高高度集成化电子产品的可靠性和使用寿命具有重要的意义。

L-lysine(Lys)graft-functionalized boron nitride nanosheets(Lys@BNNS)were successfully prepared by a combination of mechanical sand-milling exfoliation and non-covalent bond modification.Lys@BNNS and hexagonal boron nitride(h-BN)were added to thermoplastic polyurethane(TPU)to prepare composites by liquid phase mixing and hot-pressing,respectively.The structure and morphology of Lys@BNNS were characterized by Fourier transform infrared spectrometer(FT-IR),thermal gravimetric analyzer(TGA),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM)and transmission electron microscope(TEM).The effects of different filler contents on the thermal conductivity and heat emission rate of the Lys@BNNS/TPU composites were explored.The results show that the thermal conductivity of the Lys@BNNS/TPU composite is increased by 160%compared with pure TPU,when the filler mass fraction reaches 5%.This is great significance for improving the reliability and service life of highly integrated electronic products.