Self-Restructuring of Polyhydromethylsiloxanes by the Hydride Transfer Process: A New Approach to the Cross-Linking of Polysiloxanes and to the Fabrication of Thin Polysiloxane Coatings
Autor: | Urszula Mizerska, Slawomir Rubinsztajn, Julian Chojnowski, Marek Cypryk, Pawel Uznanski, Agnieszka Walkiewicz-Pietrzykowska, Witold Fortuniak |
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Jazyk: | angličtina |
Rok vydání: | 2022 |
Předmět: |
tris(pentafluorophenyl)borane
polyhydromethylsiloxane hydride transfer polymerization thin films of silicone hyperbranched polysiloxanes cross-linking of polysiloxanes Technology Electrical engineering. Electronics. Nuclear engineering TK1-9971 Engineering (General). Civil engineering (General) TA1-2040 Microscopy QH201-278.5 Descriptive and experimental mechanics QC120-168.85 |
Zdroj: | Materials, Vol 15, Iss 19, p 6981 (2022) |
Druh dokumentu: | article |
ISSN: | 1996-1944 |
DOI: | 10.3390/ma15196981 |
Popis: | The branching and cross-linking of siloxane polymers are important processes in silicone technology. A new type of such a process has been developed, which is a self-restructuring of linear polyhydromethylsiloxane (PHMS). This process involves the reorganization of the PHMS to form a highly branched siloxane polymer or finally a cross-linked siloxane network. It occurs through the transfer of a hydride ion between silicon atoms catalyzed by tris(pentafluoromethyl)borane. Its advantage over existing branching and cross-linking reactions is that it runs at room temperature without a low-molecular-weight cross-linker in the absence of water, silanol groups, or other protic compounds and it does not use metal catalysts. The study of this process was carried out in toluene solution. Its course was followed by 1H NMR, 29Si NMR and FTIR, SEC, and gas chromatography. A general mechanism of this new self-restructuring process supported by quantum calculations is proposed. It has been shown that a linear PHMS self-restructured to a highly branched polymer can serve as a pure methylsiloxane film precursor. |
Databáze: | Directory of Open Access Journals |
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