Hetero Diels-Alder Chemistry for the Functionalization of Single-Walled Carbon Nanotubes with Cyclopentadienyl End-Capped Polymer Strands

Single‐walled carbon nanotubes (SWCNTs) are pre‐functionalized with a pyridinyl‐based dithioester to undergo a hetero Diels–Alder (HDA) reaction with cyclopentadienyl end‐capped poly(methyl)methacrylate (Mn = 2700 g mol−1, PDI = 1.14). Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis (EA), and X‐ray photoelectron spectroscopy (XPS) evidence the success of the grafting process. The estimated resulting grafting density (from XPS and EA) via the HDA reaction increases by a factor of more than two (0.0774 chains·nm−2 via XPS) compared with typical values obtained via a direct cyclopentadiene driven Diels–Alder conjugation onto non‐functional SWCNTs under similar conditions. Cyclopentadienyl end‐capped polymer strands react at the surface of pre‐functionalized single‐walled carbon nanotubes with a pyridine‐based dithioester through a hetero Diels–Alder reaction. Elemental analysis and X‐ray photoelectron spectroscopy are employed to determine the grafting density.