Abstract
Polystyrene functionalized at both ends (telechelic polymer) with epoxide groups (epoxy–PS–
epoxy) was reacted with carboxylated multiwall carbon nanotubes (COOH–MWNT) in solution
in order to graft polymer chains at both ends onto the MWNT surface, forming loops. FT-IR
spectroscopy was employed to monitor the formation of aromatic esters and to quantify the
amount of telechelic grafted to the nanotube surface as a function of reaction time. When the
samples were further annealed in the melt, an increase in the aromatic ester peak was
observed, indicating that the unreacted chain ends further
grafted to MWNT surfaces to form loops. By reacting the
grafted nanotube samples further with monocarboxy terminated
poly(4-methylstyrene) (COOH–P4MS), the amount
of epoxy–PS–epoxy that had only reacted at one end was
determined. Reaction rate analysis indicates that that the
grafting of epoxy–PS–epoxy to the nanotube surface is
reaction controlled, as the FT-IR spectroscopy signal grows
as a function of approximately t0.3. These studies exemplify
how FT-IR spectroscopy can be used as a novel technique to
quantify the amount of grafted polymer, grafting rate, and
percent of difunctional polymers that form loops, and
provide a method to create loop covered nanoparticles.
