title: Graphene polyimide nanocomposites; thermal, mechanical, and high-temperature shape memory effects.
abstract: Flexible graphene polyimide nanocomposites (0.1-4 wt %) with superior mechanical properties over those of neat polyimide resin have been prepared by solution blending. Imide moieties were grafted to amine-functionalized graphene using a step-by-step condensation and thermal imidization method. The imide-functionalized graphene exhibited excellent compatibility with N-methyl-2-pyrrolidone. The dynamic storage moduli of the graphene polyimide nanocomposites increased linearly with increasing graphene content for both unmodified graphene and imidized graphene. Moduli of the imidized graphene nanocomposites were 25-30% higher than those of unmodified graphene nanocomposites. Both neat polyimide and polyimide nanocomposites exhibited shape memory effects with a triggering temperature of 230 °C. where addition of graphene improved the recovery rate. Addition of graphene improved thermal stability of the polyimide nanocomposites for both graphene and modified graphene.
authors.affiliation: Ohio Aerospace Institute, Cleveland, Ohio 44142, United States. mitra.yoonessi@gmail.com
authors.forename: Mitra
authors.initials: M
authors.lastname: Yoonessi
authors.forename: Ying
authors.initials: Y
authors.lastname: Shi
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Scheiman
authors.forename: Marisabel
authors.initials: M
authors.lastname: Lebron-Colon
authors.forename: Dean M
authors.initials: DM
authors.lastname: Tigelaar
authors.forename: R A
authors.initials: RA
authors.lastname: Weiss
authors.forename: Michael A
authors.initials: MA
authors.lastname: Meador
mesh_terms: D003460:Crystallization / Q000379:methods; D055119:Elastic Modulus; D006108:Graphite / Q000737:chemistry*; D006358:Hot Temperature; D007094:Imides / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013814:Thermal Conductivity
chemical_list: D007094:Imides; D046911:Macromolecular Substances; D006108:Graphite