Polyurethane Composites Reinforced by Isocyanate-Functionalized Multi-Walled Carbon Nanotubes and Carbon Nanofibers
Aline Granier, Tinh Nguyen, Alexander J. Shapiro, Jonathan W. Martin
The performance of polyurethane (PU) composites reinforced by isocyanate-functionalized multi-walled carbon nanotubes (NCO-fMWCNT) and isocyanate-functionalized carbon nanofibers (NCO-fCNF) has been investigated. NCO-fCNTs and NCO-fCNF were prepared using a novel method, which attaches the NCO groups to the COOH-fCNT or COOH-fCNF walls through covalent bonding. The effects of functionalization, nanofiller loading, and stochiometry on Tg and mechanical properties were studied. For comparison, unfunctionalized PU/MWCNT and PU/COOH-fMWCNT composites were also fabricated. The PU matrix was a mixture of an acrylic polyol and a biuret hexamethylene triisocyanate. Good dispersion of CNTs and CNFs in PU was accomplished by combining sonication of CNTs in solvent with high shear mechanical mixing. PU/NCO-fMWCNT composites at 0.5, 1, and 2 % loadings and NCO-fCNF at 2 % loading were prepared. Single CNT and CNT bundles were observed to be pulling out from the PU/unfunctionalized CNT composites, but CNTs appear to be imbedded in composites made with NCO-fMWCNTs. Incorporation of MWCNT and CNF in PU greatly increased the mechanical properties of this polymer. NCO functionalization appears to improving mechanical properties of PU/CNF composites, but its effect on the PU/MWCNT composites is complex, due probably to introducing defects in the CNTs by the functionalization process. The amount of MWCNT or change in the stochiometry did not appear to affect the Tg of PU. Work on measuring the dispersion of CNTs in PU and the effects of NCO functionalization on stress transfer is being investigated.
Proceedings of the Adhesion Society Meeting | 2007 |
February 1, 2007
building technology, carbon nanofiber, CNT, functionalization, NCO, polymer nanocomposites, polyurethane
, Nguyen, T.
, Shapiro, A.
and Martin, J.
Polyurethane Composites Reinforced by Isocyanate-Functionalized Multi-Walled Carbon Nanotubes and Carbon Nanofibers, Proceedings of the Adhesion Society Meeting | 2007 |, Undefined
(Accessed May 31, 2023)