Polyamino acid and Polyamide-Nanocomposites by coupled Reactions
Final Report Abstract
The objective of the project was the synthesis of polyamino acid/ or polyamide/SiO2 nanocomposites by means of twin polymerization. The main goal of combining polyamide synthesis with new deficient twin monomers for the preparation of polyamide 6/silica (PA6/SiO2) nanocomposites has been fully achieved, leading to a series of publications and a patent with the industry. Inclusion of natural amino acids in polymerizable silicon-containing twin monomers could not be achieved, because of the competing thermodynamically favored diketopiperazine formation. To achieve apparent twin polymerization starting from defined, amino acid-containing monomers, the coupled reaction of lactam-containing Si monomers and amino acids have been optimized in numerous experiments. For this purpose, new silicon containing Epsilon-caprolactam (Epsilon-CL) deficient twin monomers Si(Epsilon-CL)4, Me2Si(Epsilon-CL)2 and Me3Si(Epsilon-CL) have been developed where the Si-atom is covalently bond at the amide nitrogen of Epsilon-CL. The multiple reactant system of Si (Epsilon-CL)4, Omega-aminocaproic acid and Epsilon-caprolactam (Epsilon-CL) for the synthesis of homogeneous composite materials has proven particularly suitable. The thermodynamic coupling of three simultaneous reactions was the key to achieving novel nanostructured polyamide 6 /SiO2 hybrid materials. Although the process could be used for the large-scale production of films, but the high processing temperature of about 260 °C in the extruder induced agglomeration of the fine, initially obtained, SiO2 nanoparticles and so the nanostructuring was coarsened again. In the course of the project, the anionic polymerization of the Si-containing lactam monomers could also be developed as new and very elegant synthesis for polyamide 6/silica as well as polyamide 6/polysiloxane hybrid materials. The process takes place as activated anionic polymerization of Epsilon-CL promoted by the lactam-substituted silane monomers Si(Epsilon CL)4, Me2Si(Epsilon-CL)2 and Me3Si(Epsilon-CL). All silane monomers are excellent activators for the anionic Epsilon-caprolactam polymerization initiated by EtMgBr, resulting in short reaction times of a view minutes and high polymer yield. Studies on the thermal decomposition behavior of the lactam containing silanes indicate the formation of N-iminolactams, which do influence the activation process, as well as the pathway of the inorganic filler formation. Altogether, the chemical structure and morphology of the hybrid materials have been proven solid-state NMR and FTIR spectroscopies as well as electron microscopy. As consequence, lactam-substituted silanes monomers serve both as activator and reactant in the synthesis of Polyamide/silica and related hybrid materials.
Publications
- Method for producing polyamide composite materials containing silicon, Patent number: 9580550
Rolf-Egbert Grützner, Arno Lange, Lysann Kaßner, Andreas Seifert, Stefan Spange
- Polyamide 6/silica hybrid materials by a coupled polymerization reaction, Polym. Chem 2015, 6, 6297–6304
L. Kaßner, K. Nagel, R.-E. Grützner, M. Korb, T. Rüffer, H. Lang, S. Spange
(See online at https://doi.org/10.1039/c5py00815h) - Nanostructured Aniline Formaldehyde Resin/Polysilazane Hybrid Materials by Twin Polymerization. Macromol. Chem. Phys. 2016, 217(22), 2462–2472
L. Kaßner, A. Knoblauch, A. Seifert, R.-E. Grützner, G. Cox, A. Lange, S. Csihony, F. Simon, S. Anders, L. Kroll, M. Rahaman, D. Zahn, L. Mertens, M. Weber, M. Mehring, S. Spange
(See online at https://doi.org/10.1002/macp.201600152) - Silicon-containing Hybrid Materials, in: Twin Polymerization: New Strategy for Hybrid Materials Synthesis, 1. Auflage (Hrsg. S. Spange, M. Mehring), De Gruyter, Berlin, 2018. ISBN 978-3110500677
S. Spange, M. Göring, L. Kaßner, K. Nagel, A. Seifert
(See online at https://doi.org/10.1515/9783110499360-004) - Ternary composites by an in situ hydrolytic polymerization process, RSC Advances 2018, 8, 14713–14721
K. Nagel, L. Kaßner, A. Seifert, R.-E. Grützner, G. Cox, S. Spange
(See online at https://doi.org/10.1039/c8ra02402b) - Molecular Aspects on the Amino Acidmediated Sol-Gel Process of Tetramethoxysilane in Water, J. Sol. Gel. Sci. 2019
L. Kaßner, J. Kronawitt, D. Klimm, A. Seifert, S. Spange
(See online at https://doi.org/10.1007/s10971-019-04930-7) - Polyamide/silica hybrid materials by anionic melt polymerization of lactam-substituted silane monomers with ε-caprolactam, Eur. Polym. J. 2019
K. Nagel, S. Spange
(See online at https://doi.org/10.1016/j.eurpolymj.2019.01.072)
