Novel Star-shaped and Hyperbranched Phosphorus-containing Flame Retardants in Epoxy Resins

Lin Zang (1) , Sebastian Wagner (1) , Michael Ciesielski (1) , Patrick Mueller (1) , M Doering (1)

1 Institute of Catalysis Research and Technology

This report presents the synthesis and use of novel derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, 1) and 5,5-dimethyl-1,3,2-dioxaphosphorinan-2-one (DDPO, 2) as flame retardant additives for epoxy resins. DOPO- and DDPO-based compounds were synthesized via nucleophilic substitution with 1,3,5-tris-(2-hydroxyethyl) isocyanurate (THIC, 3) and subsequent oxidation (Scheme 1 and 2). Another trivalent DOPO derivative recently reported by our group was obtained by transamination followed by a Michaelis-Arbuzov rearrangement (Scheme 1). , These products were blended into two epoxy resin systems (DEN 438 and DGEBA, both cured with DICY and Fenuron) to obtain flame retardant thermosets. The flame retardancy and thermal properties of these epoxy resin systems were examined by UL 94-V, TGA and DSC analysis. Furthermore all reactions with phosphorus-containing compounds were iterated employing the THIC oligomer, which prepared via polycondensation of THIC (Scheme 3) using catalytic amounts of p-toluenesulfonic acid. In addition, Atherton-Todd reaction with the THIC oligomer was studied as a novel synthetic method for phosphorus-containing flame retardants (Scheme 4). , , The resulting products were utilized as flame retardants in epoxy resins and compared with the analogous monomeric compounds.

Mots clés: Physical Sciences

Lin Zang, Sebastian Wagner, Michael Ciesielski, Patrick Mueller, M Doering. Novel Star-shaped and Hyperbranched Phosphorus-containing Flame Retardants in Epoxy Resins. Polymers for Advanced Technologies, 2011, 22 (7), pp.1182. ⟨10.1002/pat.1990⟩. ⟨hal-00645109⟩