Thermally
rearrangeable aromatic polyamides (TEMPO-PA) and random
copolyamides (TEMPO-PA-COOH) incorporating alkoxyamine moieties in
the main chain were synthesized, and the effects of thermal reorganization
behavior on their solution and solid-state structures were investigated.
The hydrodynamic radius in solution decreased as the solution temperature
increased because of the dissociation of the alkoxyamine unit. Additionally,
the dry density of the thin films decreased as the fabrication temperature
increased because of the suppression of polymer aggregation caused
by the thermally induced radical crossover reaction. In addition,
at the film surface of the random copolyamide containing hydrophobic
TEMPO and hydrophilic 3,5-diaminobenzoic acid (DABA) units, the hydrophilicity
decreased as the fabrication temperature increased. This is because
hydrophobic TEMPO and hydrophilic DABA units tend to be discretely
aggregated near the film surface to minimize the surface energy and
suppress the hydrogen bonding via a radical crossover reaction during
the thin-film fabrication process. The present study clearly shows
that both the solution structure and the solid-state molecular aggregation
structure of the dynamic covalent polymers can be easily controlled
by a thermal trigger, and it provides a new method for controlling
the higher-order structure of polymer solutions and solids
