Rigid maleimide-alt-vinylpyridine copolymers with pendant chromophores. Synthesis, characterization and monolayer formation

A new series of rigid polymers was synthesized via radical copolymerization of N‐phenylmaleimides, bearing pendant chromophores, with 4‐vinylpyridine or styrene. Structural characterization was achieved by 1H NMR and 13C NMR spectroscopy, gel permeation chromatography (GPC), elemental analysis and differential scanning calorimetry (DSC). The thermal properties as well as the morphology of the investigated polymers at the air‐water interface appear to be related to their rigidity. In spite of the presence of excellent mesogenic units, the polymers do not exhibit liquid crystalline behaviour. The 4‐vinylpyridine copolymers form stable monolayers at the air‐water interface. The attached chromophores electronically behave as monomers, as shown with in situ UVVIS absorption spectroscopy. Brewster angle microscopy shows a spontaneous aggregation of these polymers into domains on a neutral subphase, whereas on an acidic subphase a more homogeneous monolayer is formed. The monolayers give Z‐type transfer onto hydrophilic quartz. However, the chromophores seem to be oriented randomly at the substrate surface. The styrene copolymers do not form stable monolayers as a result of crystallization at the air‐water interface.