Hochverzweigte, phosphorhaltige Silicapräkursoren und deren Potential als synergistisch wirksame Flammschutzmittel
- Highly branched, phosphoric silicaprecursors and their potential as synergistic flame retardants
Mäkiniemi, Roi Oskari; Möller, Martin (Thesis advisor); Pich, Andrij (Thesis advisor); Simon, Ulrich (Thesis advisor)
Aachen : RWTH Aachen University (2021)
Dissertation / PhD Thesis
Dissertation, RWTH Aachen University, 2021
Flame retardants, i.e. additives that decrease polymer flammability, are of immense importance due to the abundance of hydrocarbon plastics and textiles in everyday life. Different classes of substances are available for this, each however coming with their own limitations. While very effective halogenated flame retardants are being phased out due to environmental and health concerns, the environmentally benign mineral flame retardants exhibit rather low flame retardancy. Through synergistic interaction of different substances, however, hybrid flame retardants that are both effective as well as environmentally friendly can be produced. Therefore, this thesis covers the combination of phosphorus-containing building blocks with highly branched polyalkoxysiloxanes and polyalkoxysilsesquioxanes. To achieve this, in the first part, the commercially available silane (diethylphosphatoethyl)triethoxysilane is converted to a phosphorus-modified, highly branched polyalkoxysiloxane through a one-pot synthesis with tetraethylorthosilicate. The focus here is the synthesis and characterization of polyalkoxysiloxanes with varying contents of phosphorus-containing groups. In the second part, methods are investigated to incorporate 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, a molecule already being used as a flame retardant, into the structure of a highly branched polyalkoxysiloxane. The third part covers cyclophosphazenes, a much-investigated class of substances with high potential for flame retardancy. By crosslinking of chlorocyclophosphazenes with aminopolysilsesquioxanes, hybrid colloids are produced and characterized. Finally, these three systems are applied as textile coatings and evaluated based on their flame retardant properties.