Institut Charles Sadron Membre

Martin Hamann

  • Téléphone : 03.88.41.42.19
  • Courriel : martin.hamann@ics-cnrs.unistra.fr
  • Doctorant(e)
  • Bureau : B256
  • Equipe : MIM
  • Responsable : Wiebke Drenckhan

Morphology Control of Reactive Foams

Polyurethane (PU) foams are the most widely used class of polymer foams as they offer a wide range of tuneable properties. For example, they can be soft or rigid, and exhibit thermosetting or thermoplastic behaviour. However, the most fundamental feature of PU foams is their porous morphology: Foams with a wide variety of pore sizes and pore interconnectivities, i.e. open- and closed-cell foams, are available. As the foam’s porous morphology is key for many physical material properties, control over the porous morphology is crucial for tailoring acoustic, mechanical and thermal properties of PU foams. However, the generation of this morphology is a complex process which involves the transition from an initially liquid foam to a solid foam via formation of a crosslinked polymer network. Several interconnected steps such as chemical reactions and a multitude of physical phenomena take place during this process. Although an extensive empirical knowledge on PU foam production exists, an in-depth scientific understanding on how the morphology is influenced by certain additives or processing parameters is still lacking. Thus, the motivation of my PhD project is to gain a sound understanding of the factors influencing PU foam morphology.





One major influence on the foam morphology is the formulation of the reactive PU mixture, i.e. the chosen polyol, isocyanate, stabilisers, additives, and how these substances interact with each other. Moreover, processing conditions such as temperature and shear stress during foam generation and foam hardening influence the final foam morphology crucially. In the scope of this thesis we will systematically investigate these aspects on multiple material scales using examinations of industrial systems in parallel to purpose-designed model systems and model experiments. For example, characteristics of the bulk reactive mixture as well as those of thin films and interfaces and their impact on the final foam morphology will be studied. For this purpose, we will use an interdisciplinary approach bridging techniques and methods of chemistry, physical chemistry and physics.

The ultimate goal of this thesis is to establish a link between formulation, the processing conditions during foam formation and hardening, and the final foam morphology.


CV


2021

Steck, K.; Hamann, M.; Andrieux, S.; Muller, P.; Kekicheff, P.; Stubenrauch, C.; Drenckhan, W. (2021), Fluorocarbon Vapors Slow Down Coalescence in Foams,Advanced Materials Interfaces,8(20) : link

Hamann, M.; Quell, A.; Koch, L.; Stubenrauch, C. (2021), On how the morphology affects water release of porous polystyrene,Materials Today Communications,26() : link

2020

Dabrowski, M.L.; Hamann, M.; Stubenrauch, C. (2020), Formulation and polymerization of foamed 1,4-BDDMA-in-water emulsions,Rsc Advances,10(15) : 8917-8926 link