Synthesis and characterization of novel nonionic micellar polymers based on sulfoxides as hydrophilic group
(2001)
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- Authors
- Supervisors
- Laschewsky, André
- Abstract
- (en) This work aimed at exploring the sulfoxide moiety as new hydrophilic head for non- ionic micellar polymers, in particular for so-called polysoaps. Model surfactants and acrylic monomers incorporating a sulfoxide group, and presenting different polysoap geometries were synthesized. In this way, key properties of aqueous solutions of these monomers (so- called surfmers) and their polymers could be studied. This strategy allowed us to establish some structure-properties relationships, as well as comparisons with existing ionic and zwitterionic analogues.As there is no general access to such compounds, several synthetic pathways towards polymerizable sulfoxide compounds were explored, and the procedures adapted individually, in function of the target molécule.Our studies of tail-end geometry polysoaps, as obtained by free radical homopolymerization of our surfmers, demonstrated the limited hydrophilicity of the sulfoxide moiety for obtaining well water-soluble polymers. Nevertheless, the copolymerization of a simple sulfoxide monomer and of acrylates with long hydrophobie chain gave head type polysoaps with a high hydrophobie content, that were well soluble in water.Compared to many non-charged polysoaps, such as sulfobetaines and polyols, the newly synthesized sulfoxide polymers are characterized by good solubility into a wide range of polar organic solvents. Studies of the thermal stability showed the décomposition of the sulfoxide compounds within a température range of 130-160°C. Also, slow dégradation was observed during storage under ambient conditions.The study of the sulfoxide surfactants showed a highly effective réduction of the surface tension and very low values for the critical micelle concentration. Whereas surfmers of mid-tail geometry behave very similar to the reference compounds, the limited hydrophilicity of the sulfoxyde moiety leads to a bola-type behavior of the surfmers of tail- end geometry. Increasing the hydrophilicity by incorporating additionnai small non-ionic groups did not improve their water solubility. This illustrâtes the non-additive character of the overall hydrophilicity of amphiphiles. Apart from these particularises, the new synthesized non-ionic sulfoxide polysoaps behave as classical polysoaps, i.e.: low viscosifying effect due to a primary intramolecular aggregation, and low surface activity. Despite their low water solubility, some polysoaps of tail-end geometry undergo self-organization into lyotropic liquid crystalline phases at room température.
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Hennaux, P. (2001). Synthesis and characterization of novel nonionic micellar polymers based on sulfoxides as hydrophilic group. https://hdl.handle.net/2078.5/124333