Influence of different functionalization on mechanical and interface behavior of MWCNTs/NBR sealing composites

Rubber sealants are key components in processing industries. Carbon nanotubes (CNTs), which are randomly dispersed in polymer, are able to generate exciting effects. Focusing on mechanical properties of composites and interface characteristic between the fillers and matrix, carrying out SEM, DMA and uniaxial tensile tests, the tensile strength of the composites with 4 phr (parts by weight per hundred parts of rubber) multiwalled carbon nanotubes (MWNTs) is obviously improved. MWNTs with different functionalization have different influence on the viscoelastic and mechanical properties of the composites. Results indicate that MWNTs–COOH are broken when composites fractured. While MWNTs, MWNTs–OH and MWNTs–NH 2 are pulled out from the matrix because interface debonds under the tensile failure. The interfacial shear stress (IFSS) is about 4.7 MPa in composites. The glass transition temperature ( T g ) shifts higher temperatures compared to pure NBR (Acrylonitrile-butadiene Rubber). The presence of the nanotubes limite the movement of NBR macromolecules.