Új, olefin metatézis polimerizációban alkalmazható foszforamid égésgátló adalékanyagok fejlesztése
Flame retardant materials are important substances in our life. They can delay the ignition time or limit the spread of the fire. However, although halogen-containing flame retardants are very effective, they have negative impact on the environment . In contrast, phosphorus-containing polymers are less harmful. Therefore, the aim of our work is related to the synthesis of various monomers for obtaining flame retardant polymers with phosphorus moiety using ring-opening metathesis polymerization (ROMP).
Our first aim was to synthesize a monomer which contains phosphoramide moieties. Norbornene containing both primary amine and secondary amine were transformed to the desired flame retardant monomers which also act as crosslinkers in ROMP. The secondary amine was prepared by the formation of an imine from 5-norbornene-2-methylamine and 5-norbornene-2-carboxaldehyde followed by a reduction using NaBH4. The resulting crude product was purified by column chromatography. The pure product was reacted with phosphorus oxychloride to achieve the desired triamide.
Since norbornene is easily polymerized by ROMP, our aim was to prepare P-containing norbornene with phosphorus-carbon bond. The starting compound was maleic anhydride, an excellent substrate for Diels-Alder reactions. Norbornene-yl-anhydride was formed by the Diels-Alder reaction of maleic anhydride with in-situ generated cyclopentadiene from its dimer (DCPD) . The formed adduct was reduced to diol by LiAlH4 at 0 °C in THF . Diol was converted to the dibromide by mesylation followed by bromination. The crude product was purified by column chromatography. The next step was the Arbuzov reaction to prepare the desired diphosphonate. This monomer was effectively homopolymerized and copolymerized with norbornene to polynorbornene derivatives in the presence of ruthenium containing Grubb’s catalysts. Further advantage of this compound is its phosphor-carbon bonds which increases the resistance against fire.
All the monomers prepared were characterized by NMR and LC-MS measurements.
The copolymerization of the triamide and norbornene was carried out with different comonomer ratios, and the polymers were characterized by TG measurements.
 S. Moon, S, B. Ku, T. Emrick, E. B. Coughlin, R. J. Farris, Journal of Applied Polymer Science, 2009, 111, 301-307.
J. Appl. Polym. Sci. 2009, 111, 301
 D. Huertas, M. Florscher, V. Dragojlovic, Green Chemistry, 2009, 11, 91–95
Vegyészmérnöki alapképzési szak, levelező BSc
Dr. Kovács Ervin
tudományos munkatárs, Természettudományi Kutatóközpont (külső)
Dr. Iván Béla
kutatóprofesszor, Természettudományi Kutatóközpont (külső)
Dr. Szolnoki Beáta
adjunktus, Szerves Kémia és Technológia Tanszék