Polymer materials

Bild der Arbeitsgruppe Polymerkomposite

In the research field Polymeric Materials, new fundamental knowledge and skills are developed through scientific materials research, and the know-how and technical prerequisites are created to be able to work on the questions of application-oriented materials development at the ibac.

The working group Polymer materials also oversees chemical and instrumental analytics. More→

Current job offers and information on theses, research internships and student research projects. More→

Bio-based building materials

Nature produces a variety of substances in large quantities. Each of them has a unique combination of useful properties, which means that the potential for the development of new materials cannot even be foreseen today. Nevertheless, a large proportion is only thermally recycled or has to be disposed of in costly landfills.

In this focus, we develop methods for raw material and material recycling of biogenic residues, i. H. Substances that are produced by nature in large quantities, but have hardly been used as resources and, above all, do not compete with food production. Our main sources are poultry feathers, crab shells, insect shells and grasses. These are broken down, modified and/or processed using chemical processes in such a way that they can be integrated into the economic value chain. There, their use offers the possibility of using material-specific advantages, improving the CO2 balance and thus paving the way to a society based on renewable raw materials.

Contact person: Fabian Weitenhagen, Nils Münstermann, Paul Marten

Current projects: Bio-based glazes and adhesives for wood ❖ Biosuperabsorbers ❖ Recycling foams ❖ Biocomposite material ❖ KeraSan ❖ bio-based compounds ❖ Chitin-based bioplastics

Completed projectsBuilding material from feathers ❖ Fire protection wood

Publications:

Gels

Environmentally conscious building requires not only innovations in new construction, but also new ways of repair. Today's measures often require highly invasive intervention in the structure of the buildings. Hydrogels, i.e. water-swellable or swollen polymer networks, are an excellent alternative for sustainable, cost-effective and minimally invasive rehabilitation.

Liquid water or the periodic change of the degree of saturation plays an essential role in porous building materials in our latitudes and is not least responsible for many damages. Due to their adjustable swelling behaviour, gels can make a significant contribution to regulating the moisture balance in building materials.

      

In addition to moisture, substances introduced from the environment, such as carbon dioxide, de-icing salts, etc., can cause damage to reinforcing steels but also to the cement paste. In the current projects, we are primarily tackling the problem of corroding steel in cement-bound building materials with the help of alkaline hydrogels. Here, the principle of an ion exchanger is used to remove carbonate ions from the pore structure and replace them with hydroxide. In addition to the dynamics of the ion exchange process, methods for controlling the rheological properties of the gels in order to optimally adjust them for their respective applications, e.g. on walls, ceilings or in cracks, are essential objects of investigation. At the end of the process, our gels can be removed from the surfaces without leaving any residue.

Contact person: Tim Mrohs

Current projects: Development of a 2-component rehabilitation system for the treatment of crack flanks in reinforced concrete ❖ Development of a cationic hydrogel for concrete restoration

Completed projects: Chloride extraction with hydrogels

Publications:

  • A 3-in-1 alkaline gel for the crack injection in cement-based materials with simultaneous corrosion protection and re-passivation of crack-crossing steel rebars
    Jung, O. Weichold
    Construction and Building Materials 2022, 344, 128092. https://doi.org/10.1016/j.conbuildmat.2022.128092
  • Multivalent Allylammonium-Based Cross-Linkers for the Synthesis of Homogeneous, Highly Swelling Diallyldimethylammonium Chloride Hydrogels
    B. Mrohs, O. Weichold
    Gels 2022, 8, 100. https://doi.org/10.3390/gels8020100
  • Alkaline hydrogels as ion-conducting coupling material for electrochemical chloride extraction
    A. Jung, A. Faulhaber, O. Weichold
    Mater. Corr. 2021, 72, 1448–1455. https://doi.org/10.1002/maco.202112373 (open access).
  • Influence of Environmental Factors on the Swelling Capacities of Superabsorbent Polymers Used in Concrete
    A. Jung, M. B. Endres, O. Weichold
    Polymers 2020, 12, 2185. https://doi.org/10.3390/polym12102185  (open access).
  • Realkalisation with highly alkaline gels
    A. Jung, O. Weichold
    Concrete 201811, 422–423.
  • Preparation and characterisation of highly alkaline hydrogels for the re-alkalisation of carbonated cementitious materials
    A. Jung, O. Weichold
    Soft Matter. 201814, 8105–8111. https://doi.org/10.1039/C8SM01158C

Ion conductive polymers

Electrically and ionically conductive polymer materials based on polyethylene glycol and lithium salts not only play a central role in the energy industry, but also have great potential in the construction industry. The electrical properties form the basis of our application-oriented material development with the current focus on electrochromic detectors and polymer sensors in their applications for the detection of reinforcing steel corrosion.

Within the focus "Ion-conductive polymers", the main work for us chemists is in the area of preparative and applied polymer chemistry and we use the methods of "classical" chemical structure elucidation, such as NMR, IR or DSC. In addition, we use typical electronic measuring methods, impedance spectroscopy (EIS) and cyclic voltammetry. In the sense of interdisciplinary technology transfer, we transfer chemical facts to problems from the engineering field and thus make a significant contribution to the further development of the solution-oriented strategy pool.

Contact person: Prof. Oliver Weichold

Current projects: Development of an in situ manufactured multi-ring electrode for depth-graded monitoring of moisture behaviour in concrete components ❖ Electrochromic components for use in a corrosion or CCP monitoring system

Completed projects: Development of a system for permanent monitoring of corrosion in reinforced concrete components based on novel injectable polymer sensors

Publications:

  • Synergistic effects in cross-linked blends of ion-conducting PEO-/PPO-based unsaturated polyesters
    P. B. Sassmann, O. Weichold
    Ionics 2021, 273857–3867. https://doi.org/10.1007/s11581-021-04149-z (open access)
  • Electrochromy for the visualisation of small amounts of electricity
    T. Juraschek, O. Weichold
    Concrete 2019, 5, 168–171.
  • Preparation and characterisation of ion-conductive unsaturated polyester resins for the on-site production of resistivity sensors
    P. B. Sassmann, O. Weichold
    Ionics 201925, 3971–3978. https://doi.org/10.1007/s11581-019-02958-x
  • Development of an electrochromic device triggered by the macrocell current in chloride-induced corrosion of steel-reinforced concrete
    T. Juraschek, O. Weichold
    J. Phys. Org. Chem.
     2017;e3739. https://doi.org/10.1002/poc.3739

Analytics and process technology

To carry out research and development projects, we are constantly expanding our equipment in the area of analytics and process technology. In the field of polymer processing, we have a complete line with rolling mill, kneader, extruder and heating press for the production of composites on a laboratory scale. The contact person for polymer processing is Thomas Lohmeier.

 

Job offers

Theses (Chemistry, Civil Engineering, UIW)

Are you looking for a Bachelor or Master thesis? If one of our topics interests you, please contact Tim Mrohs or one of the above-mentioned contact persons for a non-binding discussion.

Research practicals (Chemistry M. Sc.)

Students in the degree programme Chemistry (M. Sc.) can carry out the freely selectable research internship with us. If you are interested in one of the above-mentioned research foci, please contact the responsible contact person directly, Tim Mrohs or come by for a non-binding discussion by appointment.

Student research projects (UIW)

We offer students in the environmental engineering programme the opportunity to carry out student research projects on the environmental and technological aspects of our main research areas. If you have any questions about the topics or want to narrow them down more precisely, please contact Tim Mrohs directly.

Poly News

Are you interested in innovative chemical research with direct application? Why not join us as a student assistant or researcher? More→

New publication

T. B. Mrohs, O. Weichold Hydrolytic Stability of Crosslinked, Highly Alkaline Diallyldimethylammonium Hydroxide HydrogelsGels 2022, 8, 669. https://doi.org/10.3390/gels8100669

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New publication

A. Jung, O. Weichold A 3-in-1 alkaline gel for the crack injection in cement-based materials with simultaneous corrosion protection and

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New publication

T. B. Mrohs, O. Weichold Multivalent Allylammonium-Based Cross-Linkers for the Synthesis of Homogeneous, Highly Swelling Diallyldimethylammonium Chloride Hydrogels Gels 2022,

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New doctoral student

Since January, Nils Münstermann has been supporting the research group in the area of bio-based building materials and is developing swellable chitosan derivatives for concrete and agricultural applications.

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Lecture announcement

O. Weichold Alkaline hydrogels – multifunctional materials for concrete rehabilitation – International Congress on Polymers in Concrete (IPCIC 2022) POSTPONED

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Lecture announcement

O. Weichold Highly Alkaline Hydrogels - the Swiss Army Knives of Repair NuBau - 5th Conference User-Oriented Building Rehabilitation, Weimar. POSTPONED UNTIL 2023

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New publication

M. Brenner, O. Weichold Poultry Feather Waste as Bio-Based Cross-Linking Additive for Ethylene Propylene Diene Rubber Polymers 2021, 13(22), 3908

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Master thesis completed

Congratulations to Nils Münstermann on the successful completion of his Master's thesis entitled "Synthesis and properties of superabsorbers based on

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Front page

The publication "Alkaline hydrogels as ion-conducting coupling material for electrochemical chloride extraction" by Andre Jung in Mater. Corr. has it

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New publication

P. B. Sassmann, O. Weichold Synergistic effects in cross-linked blends of ion-conducting PEO-/PPO-based unsaturated polyesters Ionics 2021, 27, 3857–3867 (open access)

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