@article{WiegandOsburg,
  author    = {Wiegand, Torben and Osburg, Andrea},
  title     = {Synthesis, Curing and Thermal Behavior of Amine Hardeners from Potentially Renewable Sources},
  series = {Polymers},
  volume    = {2023},
  journal   = {Polymers},
  number    = {volume 15, issue 4, article 990},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/polym15040990},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230524-63745},
  pages     = {1 -- 12},
  abstract  = {Research into bio-based epoxy resins has intensified in recent decades. Here, it is of great importance to use raw materials whose use does not compete with food production. In addition, the performance of the newly developed materials should be comparable to that of conventional products. Possible starting materials are lignin degradation products, such as vanillin and syringaldehyde, for which new synthesis routes to the desired products must be found and their properties determined. In this article, the first synthesis of two amine hardeners, starting with vanillin and syringaldehyde, using the Smiles rearrangement reaction is reported. The amine hardeners were mixed with bisphenol A diglycidyl ether, and the curing was compared to isophorone diamine, 4-4′-diaminodiphenyl sulfone, and 4-Aminonbenzylamine by means of differential scanning calorimetry. It was found that the two amines prepared are cold-curing. As TG-MS studies showed, the thermal stability of at least one of the polymers prepared with the potentially bio-based amines is comparable to that of the polymer prepared with isophorone diamine, and similar degradation products are formed during pyrolysis.},
  subject      = {Epoxide},
  language  = {en}
}
@inproceedings{SchirmerKleinerOsburg,
  author    = {Schirmer, Ulrike and Kleiner, Florian and Osburg, Andrea},
  title     = {Objektive Oberfl{\"a}chenbewertung von (P)SCC-Sichtbeton mittels automatisierter Analyse von Bilddaten},
  series = {Tagung Bauchemie der GDCH-Fachgruppe Bauchemie, 30. September - 2. Oktober 2019 in Aachen},
  booktitle = {Tagung Bauchemie der GDCH-Fachgruppe Bauchemie, 30. September - 2. Oktober 2019 in Aachen},
  publisher = {Gesellschaft Deutscher Chemiker},
  isbn      = {978-3-947197-13-2},
  doi       = {10.25643/bauhaus-universitaet.4510},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20211004-45104},
  pages     = {8},
  abstract  = {Sichtbeton ist aufgrund seiner Vielf{\"a}ltigkeit in der Formgebung eines der am meisten verbreiteten Gestaltungsmittel der modernen Architektur und optimal f{\"u}r neue Bauweisen sowie steigende Anforderungen an das Erscheinungsbild {\"o}ffentlicher Bauwerke geeignet. Die Herstellung qualitativ hochwertiger Sichtbetonoberfl{\"a}chen h{\"a}ngt im hohen Maße von den Wechselwirkungen zwischen Beton und Trennmittel, zwischen Trennmittel und Schalmaterial, sowie von der Applikationsart und -menge des Trennmittels ab. In Laborversuchen wurden diese Einfl{\"u}sse auf die Sichtbetonoberfl{\"a}chen eines polymermodifizierten selbstverdichtenden Betons (PSCC) im Vergleich zu einem herk{\"o}mmlichen selbstverdichtenden Beton (SCC) untersucht. Im Rahmen dieser Arbeiten wurde eine Methode zur Beurteilung der Sichtbetonqualit{\"a}t entwickelt, mit welcher Ausschlusskriterien, wie maximale Porosit{\"a}t und Gleichm{\"a}ßigkeit, objektiv und automatisiert bestimmt werden k{\"o}nnen. Ver{\"a}nderungen dieser Werte durch Witterungseinfl{\"u}sse ließen zudem erste R{\"u}ckschl{\"u}sse auf die Dauerhaftigkeit der Sichtbetonoberfl{\"a}chen zu.},
  subject      = {Sichtbeton},
  language  = {de}
}
@article{CappachionePartschefeldOsburgetal.,
  author    = {Cappachione, Clotilde and Partschefeld, Stephan and Osburg, Andrea and Gliubizzi, Rocco and Gaeta, Carmine},
  title     = {Modified Carboxymethylcellulose-Based Scaffolds as New Potential Ecofriendly Superplasticizers with a Retardant Effect for Mortar: From the Synthesis to the Application},
  series = {Materials},
  volume    = {2021},
  journal   = {Materials},
  number    = {volume 14, issue 13, article 3569},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/ma14133569},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210804-44689},
  pages     = {1 -- 17},
  abstract  = {This article is focused on the research and development of new cellulose ether derivatives as innovative superplasticizers for mortar systems. Several synthetic strategies have been pursued to obtain new compounds to study their properties on cementitious systems as new bio-based additives. The new water-soluble admixtures were synthesized using a complex carboxymethylcellulose-based backbone that was first hydrolyzed and then sulfo-ethylated in the presence of sodium vinyl sulphonate. Starting with a complex biopolymer that is widely known as a thickening agent was very challenging. Only by varying the hydrolysis times and temperatures of the reactions was achieved the aimed goal. The obtained derivatives showed different molecular weight (Mw) and anionic charges on their backbones. An improvement in shear stress and dynamic viscosity values of CEM II 42.5R cement was observed with the samples obtained with a longer time of higher temperature hydrolysis and sulfo-ethylation. Investigations into the chemical nature of the pore solution, calorimetric studies and adsorption experiments clearly showed the ability of carboxymethyl cellulose superplasticizer (CMC SP) to interact with cement grains and influence hydration processes within a 48-h time window, causing a delay in hydration reactions in the samples. The fluidity of the cementitious matrices was ascertained through slump test and preliminary studies of mechanical and flexural strength of the hardened mortar formulated with the new ecological additives yielded values in terms of mechanical properties. Finally, the computed tomography (CT) images completed the investigation of the pore network structure of hardened specimens, highlighting their promising structure porosity.},
  subject      = {M{\"o}rtel},
  language  = {en}
}