氨基化还原氧化石墨烯-碳纳米管/水性聚氨酯复合材料的制备及表征

Preparation and Properties of Aminated Reduction Graphene OxideCarbon Nanotubes/Waterborne Polyurethane Composites

采用改进的Hummers方法制得氧化石墨烯(GO),利用硅烷偶联剂(APTMS)改性氧化石墨烯后,再经L-抗坏血酸(L-AA)还原得到氨基化还原氧化石墨烯(KRGO),并与碳纳米管(CNT)作为协同改性剂,与水性聚氨酯(WPU)预聚体复合得到KRGO-CNT/WPU复合物,以期改善WPU涂膜的力学性能、热稳定性和耐水性。采用FT-IR、XRD、TEM、SEM和TG等测试手段对复合物的结构和性能进行表征。结果表明:APTMS成功地插入了GO片层,明显地改善了复合材料的力学性能、疏水性与热性能。当KRGO-CNT的质量分数为0.5%时,涂膜拉伸强度从纯WPU的14.10MPa增大到35.49MPa,增幅达152%;KRGO-CNT/WPU涂膜质量损失为5%时的温度(T5%)比纯WPU高29.3℃;当KRGO-CNT的质量分数为0.8%时,涂膜静态水接触角从纯WPU的54.7°增大到82.8°.

A graphene oxide (GO) was prepared by the modified Hummers method. Then an aminated reduced graphene oxide (KRGO) was obtained by GO modified with silane coupling agent (APTMS) followed by reduction with L-ascorbic acid (L一AA). The prepared KRGO was mixed with carbon nanotubes (CNT) as synergistic modifier, and then was combined with waterborne polyurethane (WPU) to get KRGO- CNT/WPU composites, by which the mechanical properties, poor thermal stability and water resistance, etc. of WPU were improved. The structure and properties of the composites were characterized by FT-IR, TEM,SEM,XRD and TG. The results showed that APTMS successfully interlaid the GO sheet and significantly improved the mechanical properties, hydrophobic and thermal properties of the composites. When the mass ratio of KRGO-CNT was 0.5%, the tensile strength of KRGO-CNT/WPU composites increased from 14.10 MPa to 35.49 MPa, showing 152%higher than that of pure WPU. In addtion, the temperature of KRGO-CNT/WPU at the thermal weight loss of 5% was 29.3℃ higher than that of the pure WPU. When the mass ratio of KRGO-CNT was 0.8%, the static water contact angle increased from 54.7° to 82.8°.