The adsorption ability
of porous carbons toward contaminants is
closely related to the porous structures and the working functional
groups. In this aspect, two porous carbons, with the potential use
as adsorbents for CO
2
and iodine, were prepared from polycyclotrimerizations
(PCTs) of flexible bisphenyl A dicyanate (BPAC) and rigid binaphthalenyl
dicyanate (BNC) cyanate ester monomers. Primarily, PCT reactions of
BPAC and BNC generated the respective nonporous c-BPAC and c-BNC precursors,
which contain high amounts of nitrogen and oxygen heteroatoms. Further
KOH activations of c-BPAC and c-BNC produced the respective porous
a-BPAC and a-BNC carbons, which mainly contain oxygen heteroatoms.
The a-BNC derived from rigid BNC contains both micro- and mesopores
and is high in adsorbing both CO
2
(6.3 mmol/g) and iodine;
in contrast, the microporous a-BPAC is lower in adsorbing CO
2
(3.9 mmol/g) and iodine. The effects of molecular flexibility of
the starting cyanate ester on the micro- and mesopore distribution
as well as the CO
2
and iodine adsorption behaviors of the
porous carbons are therefore probed in this study.