title: Toward high performance thermoset/carbon nanotube sheet nanocomposites via resistive heating assisted infiltration and cure.
abstract: Thermoset/carbon nanotube (CNT) sheet nanocomposites were successfully fabricated by resistive heating assisted infiltration and cure (RHAIC) of the polymer matrix resin. Resistive heating takes advantage of the electrical and thermal conductivity of CNTs to rapidly and uniformly introduce heat into the CNT sheet. Heating the CNT sheet reduces the viscosity of the polymer resin due to localized temperature rise in close proximity to the resin, which enhances resin flow, penetration, and wetting of the CNT reinforcement. Once the resin infusion process is complete, the applied power is increased to raise the temperature of the CNT sheet, which rapidly cures the polymer matrix. Tensile tests were used to evaluate the mechanical properties of the processed thermoset/CNT sheet nanocomposites. The improved wetting and adhesion of the polymer resin to the CNT reinforcement yield significant improvement of thermoset/CNT nanocomposite mechanical properties. The highest specific tensile strength of bismaleimide(BMI)/CNT sheet nanocomposites was obtained to date was 684 MPa/(g/cm(3)), using 4 V (2 A) for resin infiltration, followed by precure at 10 V (6 A) for 10 min and post curing at 240 °C for 6 h in an oven. The highest specific Young's modulus of BMI/CNT sheet nanocomposite was 71 GPa/(g/cm(3)) using resistive heating infiltration at 8.3 V (4.7 A) for 3 min followed by resistive heating cure at 12.5 V (7 A) for 30 min. In both cases, the CNT sheets were stretched and held in tension to prevent relaxation of the aligned CNTs during the course of RHAIC.
authors.affiliation: National Institute of Aerospace , Hampton, Virginia 23666, United States.
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Kim
authors.forename: Godfrey
authors.initials: G
authors.lastname: Sauti
authors.forename: Emilie J
authors.initials: EJ
authors.lastname: Siochi
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Smith
authors.forename: Russell A
authors.initials: RA
authors.lastname: Wincheski
authors.forename: Roberto J
authors.initials: RJ
authors.lastname: Cano
authors.forename: John W
authors.initials: JW
authors.lastname: Connell
authors.forename: Kristopher E
authors.initials: KE
authors.lastname: Wise
keywords: nanocomposite; resistive heating; thermoset/carbon nanotube