18th November 2017

Polymer morphology

Morphology is “the study of shape”. In the case of polymers, “morphology” describes the study of the microscopic appearance of a polymeric material. While a number of physicochemical properties, such as crystallinity, cannot be “seen”, the appearance of a material can still be indicative for certain properties. Crystallinity for instance often goes hand in hand with facetted objects showing sharp edges.

In our research on both crystalline monomers and polymers, as well as non-classical polymerizations, morphological studies are crucial. For these studies, we mainly employ microscopy techniques, i.e. optical microscopy as well as electron microscopy (scanning and transmission electron microscopy, SEM and TEM).

Morphological studies have helped us to get insights into mechanistic aspects of hydrothermal and solid-state polymerization (HTP and SSP), and the quality and crystal growth of monomer salts and co-crystals.[1-4] In HTP for instance, we work in closed reactors at high temperatures and pressures, which one cannot simply open in the course of reaction to analyze the ongoings.  Here, we often perform intensive parameter studies and analyze non-purified crude products for developing hypotheses of these reactions.[1-3]

Here are a few pictures:

References:

[1] B. Baumgartner, M. J. Bojdys and M. M. Unterlass*, Polym. Chem. 20145, 3771-3776. “Geomimetics for Green Polymer Synthesis: Highly Ordered Polyimides via Hydrothermal Techniques”

[2] B. Baumgartner, M. Puchberger, M. M. Unterlass*, Polym. Chem. 20156, 5773-5781. “Towards a General Understanding of Hydrothermal Polymerization of Polyimides“

[3] B. Baumgartner, M. J. Bojdys, P. Skrinjar and M. M. Unterlass*, Macromol. Chem. Phys. 2016217, 485-500. “Design Strategies in Hydrothermal Polymerization of Polyimides”

[4]  K. Kriechbaum, D. A. Cerrón-Infantes, B. Stöger and M. M. Unterlass*, Macromolecules 201548, 8773-8780.Shape-Anisotropic Polyimide Particles by Solid-State Polycondensation of Monomer Salt Single Crystals