Effect of Molecular Chain Length on the Mechanical and Thermal Properties of Amine-Functionalized Graphene Oxide/Polyimide Composite Films Prepared by In Situ Polymerization

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• 作者：Wei-Hao Liao ; Shin-Yi Yang ; Jen-Yu Wang ; Hsi-Wen Tien ; Sheng-Tsung Hsiao ; Yu-Sheng Wang ; Shin-Ming Li ; Chen-Chi M. Ma ; Yi-Fang Wu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：February 13, 2013
• 年：2013
• 卷：5
• 期：3
• 页码：869-877
• 全文大小：597K
• 年卷期：v.5,no.3(February 13, 2013)
• ISSN：1944-8252

文摘

This study fabricates amine (NH₂)-functionalized graphene oxide (GO)/polyimide(PI) composite films with high performance using in situ polymerization. Linear poly(oxyalkylene)amines with two different molecular weights 400 and 2000 (D400 and D2000) have been grafted onto the GO surfaces, forming two types of NH₂-functionalized GO (D400-GO/D2000-GO). NH₂-functionalized GO, especially D400-GO, demonstrated better reinforcing efficiency in mechanical and thermal properties. The observed property enhancement are due to large aspect ratio of GO sheets, the uniform dispersion of the GO within the PI matrix, and strong interfacial adhesion due to the chemical bonding between GO and the polymeric matrix. The Young鈥檚 modulus of the composite films with 0.3 wt % D400-GO loading is 7.4 times greater than that of neat PI, and tensile strength is 240% higher than that of neat PI. Compared to neat PI, 0.3 wt % D400-GO/PI film exhibits approximately 23.96 掳C increase in glass transition temperature (T_g). The coefficient of thermal expansion below T_g is significantly decreased from 102.6 渭m/掳C (neat PI) to 53.81 渭m/掳C (decreasing 48%) for the D400-GO/PI composites with low D400-GO content (0.1 wt %). This work not only provides a method to develop the GO-based polyimide composites with superior performances but also conceptually provides a chance to modulate the interfacial interaction between GO and the polymer through designing the chain length of grafting molecules on NH₂-functionalized GO.

Keywords:

graphene oxide; amine-functionalized; polyimide; composites; in situ polymerization