Research strand 1: Synthesis and characterisation of special polymers
The synthesis of special materials and model polymers is the base for most research projects in our group. Normally anionic polymerisation, radical polymerisation or emulsion polymerisation are used. The common aspects for all investigation are polymer based materials and the influence of specific molecular properties on the resulting macroscopic material properties.
An important aspect of this strand are self-organizing polymer structures based on block copolymers. One actual example here is the influence of the topology and/or morphology on the foaming properties of polymers and copolymers. Another part is the fatigue behaviour of polymers and the influence of tri- and diblock copolymers.
Another aspect of this research strand is the correlation of topology with the final melt properties. Here the effect of molecular weight, topology and monomer type on the resulting properties have been studied, an actual project is the synthesis of comb polymers where either backbone or side chains consist of deuterated material offering the possibility to see the effect of the mobility of one selectable part in 1H-NMR relaxation spectroscopy.
Another important topic is the study of rubber materials where the influence of the filler material and the interface and the interaction between the matrix and the filler plays an important role. In addition, also composite materials (polymer + CNT or inorganic fillers) and emulsion are subjects of ongoing research.
|Please see also the full list of publications|
|Fatigue life prediction via the time-dependent evolution of linear and nonlinear mechanical parameters determined via Fourier transform of the stress||V. Hirschberg; M. Wilhelm; D. Rodrigue; Journal of Applied Polymer Science 135, 46634 (2018); DOI 10.1002/app.46634|
|Diblock Copolymers with Similar Glass Transition Temperatures in Both Blocks for Comparing Shear Orientation Processes with DPD Computer Simulations||M. Heck; L. Schneider; M. Müller; M. Wilhelm; Macromolecular Chemistry and Physics 219, 1700559 (2018); DOI 10.1002/macp.201700559|
|Polystyrene comb architectures as model systems for the optimized solution electrospinning of branched polymers||K. Riazi, J. Kübel, M. Abbasi, K. Bachtin, S. Indris, H. Ehrenberg, R. Kádár, M. Wilhelm; Polymer 104, 240-250 (2016); DOI 10.1016/j.polymer.2016.05.032|
|Synthesis and Linear and Nonlinear Melt Rheology of Well-Defined Comb Architectures of PS and PpMS with a Low and Controlled Degree of Long-Chain Branching||M. Kempf, D. Ahirwal, M. Cziep, M. Wilhelm; Macromolecules 46, 4978-4994 (2013); DOI 10.1021/ma302033g|
Example 1: Synthesis of Comb model systems
(see [Kempf et al., 2013])
Comb structures can be achieved in different ways, we selected a synthesis path via a grafting to approach that offers the advantage of Advantage: Independent synthesis and characterization of the branches and of the backbone.
Grafting to approach for the synthesis of comb polymers
Fig.2: Anionic synthesis of comb polymers and grafting onto of the side chains
With these models systems, it was possible to study the influence of a low amount of side chains on the melt behavior of the polymer offering, for the first time, the chance to correlate the melt behaviour quantitatively to the number and the length of the branches.