How solvent-free crosslinking conditions alter the chemistry and topology of hemiketal based polymer networks
T. Urbaniak; K.G. Hoffmann; M. Herrera-Glomm; H. Oschkinat; P. Schmieder; K. Koschek*
Polymer 229, 123986 (2021)
BA solvent free reaction of PCL based
polyester polyols with a crosslinking molecule based on a vicinal
tricarbonyl
results covalent adaptable polymer networks that differ in
their thermal behavior, swelling, and solubility
properties. Mild
processing results polymer networks based on hemiketal/ketone equilibrium
with properties
typical for dissociative networks including dissolution
in presence of water or elevated temperature and selfhealing
properties.
Further thermal treatment of the polymer entails changes in swelling, and
solubility properties.
Constant glass transition temperatures of the
differently treated polymers indicate a steady overall
network density,
but changes in the nature of the network structure. By varying the number
of OH-groups, molar
mass and stoichiometric ratio of the polyester
polyol and the crosslinking molecule, respectively, material
properties
can be adjusted. This approach gives access to reversibly crosslinked
polymers varying in their
responsivness and overall mechanical
properties.