文献类型：期刊文献

英文题名：Preparation and properties of thermostable well-functionalized graphene oxide/polyimide composite films with high dielectric constant, low dielectric loss and high strength via in situ polymerization

作者：Fang, Xinliang[1];Liu, Xiaoyun[1];Cui, Zhong-Kai[2];Qian, Jun[1];Pan, Jijia[1];Li, Xinxin[1];Zhuang, Qixin[1]

机构：[1]E China Univ Sci & Technol, Key Lab Specially Funct Polymer Mat & Related Tec, Sch Mat Sci & Engn, Minist Educ, Shanghai 200237, Peoples R China;[2]Univ Montreal, Dept Chem, Montreal, PQ H3C 3J7, Canada

年份：2015

卷号：3

期号：18

起止页码：10005

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY A

收录：;EI(收录号：20151900825571);WOS:【SCI-EXPANDED(收录号:WOS:000353927500081)】；

基金：This work was financially supported by the Basic Innovation Research Program of Science and Technology Commission of Shanghai (13JC1402002), the Natural Science Foundation of Shanghai (12ZR1407900) and the China Scholarship Council.

语种：英文

外文关键词：Film preparation - Oxide films - Composite films - Thermogravimetric analysis - Oxalic acid - Polymerization - Tensile strength - Dielectric devices - Dispersions - Elastic moduli - Graphene

摘要：This study proposes a novel and facile method to synthesize high-quality NH2-functionalized and carboxyl-functionalized graphene oxide (PPD-CFGO)/polyimide (PI) composite films with high dielectric constant (3), low dielectric loss, high-temperature resistance and outstanding mechanical properties by in situ polymerization. In addition to the partial carboxyl groups located at the edges, the ample hydroxyl and epoxy groups bonded on the basal plane of graphene sheets were exploited to covalently bond to the amines. GO was modified by oxalic acid to obtain carboxyl-functionalized GO (CFGO) before amidation. NH2-functionalized CFGO (PPD-CFGO), dispersing well in dimethylacetamide (DMAc), was the initial platform for polymer grafting to improve the CFGO dispersion in the polymer matrix. Partially reduced graphene nanosheets are formed during the imidization process. The PPD-CFGO/PI composite films exhibit high tensile strength (up to 848 MPa) and Young's modulus (18.5 GPa). The thermogravimetric analysis results indicate that the PPD-CFGO/PI composites have good thermal stability below 500 degrees C. The dielectric constant increases up to 36.9 with an increasing amount of PPD-CFGO, higher than that of the pure PI polymer by a factor of 12.5, while the dielectric loss is only 0.0075 and the breakdown strength still remains at a high level (132.5 + 9.3 MV m(-1)).