Introduction of multiple hydrogen bonding for enhanced mechanical performance of polymer-carbon nanotube composites

Due to their outstanding mechanical properties and high aspect ratios, carbon nanotubes (CNTs) are envisioned as attractive nanofillers in polymer composites. However, due to strong van der Waals interactions, deleterious aggregation of CNTs is typically observed in polymer nanocomposites. Moreover, due to low stress transfer between the matrix polymer and the nanotube filler, only limited reinforcement is obtained.We report here a novel functionalization strategy to obtain CNTs with pendant self-complementary hydrogen bonding groups in order to address these limitations. Multi-walled CNTs were functionalized with ureidopyrimidinone (UPy) groups, which display multiple hydrogen bonding. The functionalized CNTs were blended with acrylic copolymers containing pendant UPy moieties and significant enhancement in tensile performance of the nanocomposites was observed.