氧化石墨烯/聚酰亚胺复合薄膜的制备及阻水性能

以石墨粉为原料，采用改进的Hummers法制备氧化石墨烯（GO），采用原位聚合法制备GO/聚酰亚胺酸（PAA）前驱体，GO/PAA前驱体经高温固化处理后得到GO/聚酰亚胺（PI）复合薄膜；采用XRD、Raman、FTIR、AFM等表征手段对GO的结构进行表征；此外，研究了不同固化温度下PI薄膜的结构；最后测试了GO/PI复合薄膜的透湿率和力学性能。结果表明:GO为单层结构，厚度为1.26 nm。GO/PI复合薄膜表现出良好的阻水性能，当GO/PI复合薄膜中GO的添加量为0.025wt%、薄膜厚度为50 μm时，GO/PI复合薄膜的透湿率低至56.7 g（m2·d）-1。此外，0.025wt% GO/PI复合薄膜拉伸强度和断裂伸长率分别为150.8 MPa和13.5%，与PI薄膜（分别为126.9 MPa和8.1%）相比，分别增加了18.8%和66.7%。 

Preparation and water-blocking property of graphene oxide/polyimide composite film

Graphene oxide (GO) was prepared by the modified Hummers method with graphite powder as the raw material. The GO/polyamic acid (PAA) precursor was synthesized by in-situ polymerization, and further imidized into GO/polyimide(PI) film by heating. The GO was characterized by XRD, Raman, FTIR and AFM, and the structure of PI films at different curing temperatures was studied. Then, the water vapor transmission rate and mechanical properties of GO/PI film were tested. The results reveal that the GO has a single layer structure with its thickness of 1.26 nm. The GO/PI composite film exhibites good water resistance performance. The water vapor transmission rate of the GO/PI composite film (thickness of the film is 50 μm) containing 0.025wt% GO is as low as 56.7 g(m²·d)^-1. The mechanical properties measurements suggest that the tensile strength and the elongation at break of the 0.025wt%GO/PI composite film are 150.8 MPa and 13.5%, respectively, increasing by 18.8% and 66.7% as compared to that of PI film (126.9 MPa and 8.1%).