Experimental and theoretical evaluations of the interfacial interaction between carbon nanotubes and carboxylated butadiene nitrile rubber: Mechanical and damping properties

The success of carbon nanotubes (CNTs) as fillers in improving the physicochemical and mechanical properties of polymer is attributed to their unique structure and performance characteristics. The interfacial interaction between fillers and matrix is of significant influence in agglomeration of fillers and mechanical/damping properties of as-prepared composites. Here, polydopamine (PDA), (3-Aminopropyl) triethoxysilane (KH550) and ionic liquid (1-aminoethyl-3methylimidazolium bis ((trifluoromethyl) sulfonyl) imide)) were used to not only functionalize CNTs for suppressing their agglomeration, but also regulate the interfacial interaction between CNTs and carboxylated butadiene nitrile rubber (XNBR) for achieving excellent mechanical properties and better damping properties. The storage modulus of composites rose by 80% (from 1392 to 2488 MPa) with the addition amount of 2.2 wt% CNTs-KH550 and the tensile strength rose by 110% (from 0.32 to 0.68 MPa) with 3.0 wt% CNTs-IL. In addition, the damping degradation of composites caused by the agglomeration of fillers was resolved. The results of molecular dynamics (MD) simulation show that the strong interfacial interaction of CNTs-PDA and CNTs-KH550 is mainly attributed to hydrogen bond interaction, while the interaction of CNTs-IL is determined by hydrogen bond interaction and van der Waals' (vdW) force. The functionalized CNTs with excellent interfacial interaction and dispersion have bright application prospects in the field of composite. [Display omitted] •Prepared three functionalized CNTs by grafting PDA, KH550 and ionic liquid.•Improved the dispersion of CNTs in XNBR through functionalization.•Enhanced the mechanical properties (80%) of XNBR composite and suppressed the decrease in damping properties.•Analyzed the interfacial interaction between filler and matrix by molecular dynamics simulation on the molecular scale.