@article{SchamelBauerSchlachteretal.2025, author = {Schamel, Elisabeth and Bauer, Florian and Schlachter, Herbert and Wehnert, Gerd and S{\"o}thje, Dominik}, title = {Bio-Based Epoxy Resins Derived from Eugenol with High Glass Transition Temperatures as Substitutes for DGEBA}, series = {Macromolecular Materials and Engineering}, journal = {Macromolecular Materials and Engineering}, publisher = {Wiley}, address = {Weinheim}, issn = {1439-2054}, doi = {10.1002/mame.202400394}, pages = {12}, year = {2025}, abstract = {Epoxy resins (EPs) are crucial for high-performance applications like lightweight materials, due to their excellent properties. However, the commonly used diglycidyl ether of bisphenol A (DGEBA) has two major disadvantages: it is synthesized mainly from petrochemicals and includes the health concerning bisphenol A. Eugenol is a bio-based aromatic compound that can be modified into di- or triglycidyl ether. Through investigations four monomers are obtained based on eugenol and crosslinked with two curing agents isophorone diamine and 4,4′-diaminodiphenyl sulfone to compare the properties of the resulting EPs with references containing DGEBA. Using new synthesis routes, the bio-content of the monomers can be increased up to 94 wt\%. Intramolecular cyclization occurs if a hydroxy group is in ortho-position to the glycidyl ether group. The crosslinking conditions of the bio-based monomers are comparable to or lower than those of DGEBA. The eugenol-based triglycidyl monomers exhibit very high glass transition temperatures of up to 271 °C, almost 50 °C above the reference value, which can enable their use for lightweight construction such as matrices for fiber-reinforced plastics. The char content of all bio-based EPs after pyrolysis is significantly higher in comparison to the references, which may have a favorable effect on fire resistance.}, language = {en} } @article{BauerSoethjeSchlachteretal.2024, author = {Bauer, Florian and S{\"o}thje, Dominik and Schlachter, Herbert and Wehnert, Gerd}, title = {Mechanical properties of carbon nanotube (CNT) reinforced polymers using electron-deficient aromatics as additives}, series = {Polymer Composites}, volume = {2024}, journal = {Polymer Composites}, publisher = {Wiley}, issn = {0272-8397}, doi = {https://doi.org/10.1002/pc.28695}, pages = {1 -- 16}, year = {2024}, abstract = {Abstract In initial experiments the effects of aromatic model substances on carbon nanotube (CNT) dispersions in dimethylformamide (DMF) were investigated. Electron-deficient aromatics interact strongly with CNTs, causing increased agglomeration and sedimentation. Conversely, electron-donating aromatics stabilize CNT dispersions in DMF. Polymers with electron-deficient aromatics, such as polyd initrostyrene (PDNS), exhibit a concentration-dependent effect: low concentrations lead to stabilization of dispersions, while higher concentrations lead to sedimentation. This suggests that such polymers can enhance attraction between the matrix of CNT-reinforced polymers as well as stabilize the dispersed CNTs. Polycarbonate, modified with polydinitrocarbonate (PDNC) and reinforced with CNTs showed improved mechanical properties. The addition of 6 wt.\% CNTs and 6 wt.\% PDNC resulted in a notable improvement with a 22\% increase in tensile strength, a 29\% increase in flexural strength, a 39\% increase in Young's modulus and a 47\% increase in flexural modulus. This enhancement resulted in an overall mechanical performance comparable to the high-performance polymer polyetherimide. However, there must be noted, that the addition of PDNC increases the CNT particle size, which can negatively affect mechanical properties. The results highlight the additive's dual role in enhancing adhesive interactions while potentially increasing CNT agglomerate sizes.Highlights Interactions of CNTs dispersed in DMF and various aromatics were investigated. Polydinitrocarbonate (PDNC) was synthesized as a new additive for CNT-composites. Polycarbonate/CNT-composites were obtained using extrusion. Test specimens with CNT contents up to 6 wt.\% were obtained. Mechanical properties of polycarbonate reached the level of polyetherimide.}, language = {en} } @article{SoethjeWehnertSchameletal.2022, author = {S{\"o}thje, Dominik and Wehnert, Gerd and Schamel, Elisabeth and Bauer, Florian and Schlachter, Herbert}, title = {Nachhaltig und sicher fliegen - nur eine Zukunftsfantasie?}, series = {OHM Journal}, volume = {2022}, journal = {OHM Journal}, number = {2}, publisher = {Technische Hochschule N{\"u}rnberg}, address = {N{\"u}rnberg}, pages = {66 -- 69}, year = {2022}, abstract = {Flugreisen und Luftverkehr sind brennende Themen, wenn es um den {\"o}kologischen Fußabdruck geht. Damit besch{\"a}ftigt sich das Forschungsteam um Prof. Dr. Gerd Wehnert und Prof. Dr.-Ing. Dominik S{\"o}thje von der Fakult{\"a}t Angewandte Chemie. In ihrem Projekt bio-Lufa entwickelt es Faserverbundwerkstoffe auf Grundlage von nachwachsenden Rohstoffen f{\"u}r die Luftfahrt.}, language = {de} } @article{WehnertSoethjeSchlachteretal.2023, author = {Wehnert, Gerd and S{\"o}thje, Dominik and Schlachter, Herbert and Bauer, Florian}, title = {C-Mat - Cabon-nanoverst{\"a}rkte Kunststoffmaterialien}, series = {Vorlaufforschung 2022}, volume = {2022}, journal = {Vorlaufforschung 2022}, publisher = {TH N{\"u}rnberg}, address = {N{\"u}rnberg}, issn = {1867-4585}, pages = {125 -- 142}, year = {2023}, abstract = {In diesem Vorlaufforschungsprojekt sollen kommerzielle Carbon Nanotubes (CNTs), die als Agglomeratpulver anfallen, durch geeignete Additive funktionalisiert und vereinzelt werden, um sie in eine Epoxidharzmatrix einzubetten. Die CNTs wurden in L{\"o}sungen verschiedener aromatischer Molek{\"u}le mittels Ultraschallbad dispergiert und die Partikelgr{\"o}ßenverteilung durch Lichtstreuung bestimmt. Es ließ sich eine partielle Verschiebung der Partikelgr{\"o}ßen durch die Einwirkung der Additive zu kleineren Durchmessern beobachten. Aufbauend auf den Ergebnissen wurden die CNTs in L{\"o}sung mit aromatischen Molek{\"u}len funktionalisiert und anschließend durch ein Dreiwalzwerk in ein Epoxidharz eingearbeitet. Die hergestellten Komposite wurden mechanisch gepr{\"u}ft, eine Steigerung der Festigkeit war aber bislang nicht zu beobachten. Wir vermuten, dass die Aufl{\"o}sung der CNT-Kn{\"a}uel und die Verhinderung der CNT-Re-Agglomeration entscheidend f{\"u}r die Wirksamkeit der Verst{\"a}rkung ist.}, language = {de} } @article{SoethjeKuehlBaueretal.2023, author = {S{\"o}thje, Dominik and K{\"u}hl, Hannes and Bauer, Florian and Beier, Julian and Hendrawidjaja, Handoyo}, title = {REnuka - Reduktion von Emmisionen durch nachhaltige Binder f{\"u}r Hochleistungskeramiken}, series = {Vorlaufforschung / Schriftenreihe der Georg-Simon-Ohm-Hochschule, N{\"u}rnberg (2023)}, journal = {Vorlaufforschung / Schriftenreihe der Georg-Simon-Ohm-Hochschule, N{\"u}rnberg (2023)}, issn = {1867-4585}, pages = {99 - 113}, year = {2023}, abstract = {In diesem Vorhaben wurden verschiedene Bindemittel f{\"u}r die Herstellung von Hochleistungskeramiken analysiert. Ziel war es, biobasierte Binder zu identifizieren, die konventionelle auf fossilen Ressourcen basierende Systeme in Zukunft ersetzen k{\"o}nnen. Es wurden drei erd{\"o}lbasierte Referenz-Bindersysteme und sieben biobasierte Alternativen bez{\"u}glich ihrer thermischen Stabilit{\"a}t unter Sauerstoffatmosph{\"a}re, der Viskosit{\"a}t ihrer w{\"a}ssrigen L{\"o}sungen oder Dispersionen sowie daraus hergestellter Schlicker und ihrer Haftung auf Aluminiumoxid-basierter Keramik untersucht. Im Rahmen des Vorhabens konnte ein biobasiertes Bindersystem mit Eigenschaften, vergleichbar zum besten Referenzmaterial gefunden werden. Unter Einsatz des biobasierten Binders sowie zweier ausgew{\"a}hlter Referenz-Bindersysteme wurden Gr{\"u}nk{\"o}rper hergestellt und deren Festigkeit ermittelt. Die Gr{\"u}nk{\"o}rperfestigkeit ist in der keramischen Industrie ein entscheidender Faktor und stark vom gew{\"a}hlten Bindersystem abh{\"a}ngig. Die erhaltenen Resultate deuten darauf hin, dass der Bio-Binder auch hinsichtlich der Festigkeitswerte den konventionellen Referenz-Bindersystemen als gleichwertig anzusehen ist. Die in diesem Vorlauf- forschungsprojekt gewonnenen Erkenntnisse k{\"o}nnen als Ausgangslage f{\"u}r die Beantragung weiterer F{\"o}rdermittel und die Akquise direkter Drittmittel aus der Industrie dienen.}, language = {de} } @article{BauerElisabethHerbertetal.2025, author = {Bauer, Florian and Elisabeth, Schamel and Herbert, Schlachter and Wehnert, Gerd and S{\"o}thje, Dominik}, title = {Bio-Based Epoxy Resins from Estragole: Achieving High Glass Transition Temperatures Comparable to DGEBA and Simultaneously Low Viscosities}, series = {Macromolecular Materials and Engineering}, volume = {311}, journal = {Macromolecular Materials and Engineering}, number = {3}, publisher = {Wiley}, address = {Weinheim}, issn = {1439-2054}, doi = {10.1002/mame.202500418}, pages = {1 -- 18}, year = {2025}, abstract = {This study covers the synthesis and characterization of two new bio-based epoxy monomers, diglycidyl-4-allylphenol (DG-4A) and triglycidyl-diallylphenol (TG-DA). Both are derived from estragole, a naturally occurring allylbenzene and a major component of the essential oils in basil. The resulting epoxy monomers, with high bio-contents of 92\% (DG-4A), respectively 72\% (TG-DA), were cured using two different amine hardeners: isophorone diamine (IPDA) and 4,4´-diaminodiphenyl sulfone (DDS). The curing agents were selected for their distinct properties: IPDA for its bio-based availability, and DDS for its ability to impart high thermal stability and rigidity. Dynamic mechanical analysis (DMA) showed that DG-4A/DDS had a high glass transition temperature (Tg) of 236°C, which can compete with the petrochemical-based reference system DGEBA/DDS (Tg = 238°C). For the TG-DA networks, the resulting Tgs were 235°C (IPDA) and 300°C (DDS), both were higher than those of the DGEBA reference systems, due to higher crosslinking density. The dynamic viscosities of DG-4A and TG-DA were 80 and 15 times lower than those of the reference DGEBA at room temperature. These results suggest that DG-4A and TG-DA are sustainable alternatives to DGEBA, as they offer comparable or higher glass transition temperatures while maintaining lower viscosities, making them promising candidates for applications requiring high thermal performance, such as in the aerospace and automotive sectors.}, language = {en} }