Synthesis And Flame Resistance Study Of Phosphorus-Nitrogen Type Intumescent Flame Retardant Containing 1,3,2-Dioxaphosphorinane Unit

Fire disasters make great number of deaths and heavy property loss every year all over the world. Treating inflammable materials with flame retardants is one of the strategic measures to prevent and decrease fire disasters. The study, produce and use of flame retardants and fireproofing materials are significant behaves that concerning " ENVIRONMENT AND HUMAN " problem.Organic flame retardant includes halogenated and phosphated flame retardant. Halogenated flame retardant set off attention because of dioxin (toxicity of splitting decomposition and combustion products) problem. People attach importance to phosphated flame retardant especially intumescent flame retardant which containing no halogen and antimony. Being an effective way to produce nonhalogen flame retardant and with merits of low smoking and low toxicity, Intumescent flame retardant has a positive prospect. Intumescent flame retardant which containing carbon source,acid source and gas source as a whole has received increasing interest in the investigate and develop fields of phosphorus-containing flame retardant. To get further information, we introduced the structure of 1,3, 2-dioxaphosphorinane through Pudovik addition and salt forming reaction and have synthesized 26 novel compounds : (1) N, N ' -phenylenediamino-Dibenzyl-a-amino-5, 5-dimethyl-4-heteroaryl-2-oxy-1,3, 2-dioxaphosphorinane phosphonate; (2)5, 5-dimethyl-4-heteroaryl-2-amide-ethyl-2-oxy-l, 3, 2-dioxaphosphorinane phosphonate (and it's N-hydroxymethyl product); (3) 5, 5-dimethyl-4-heteroaryl-2-oxy-l, 3, 2-dioxaphosphorinane phosphate melamine salt. The reaction conditions and aftertreatment process were studied and improved. The structures of the title compounds were confirmed by IR^HNMR, 13 CNMR, 31 PNMR, MS and elementary analysis. The spectroscopy properties were investigatedsystemetically. Result shows that the structures of the synthesized compounds are identical with the expected ones.TG and DTA analysis of some of the compounds were discussed. Most of the compounds begin to decompose at 220 and have certain thermal stability. They decompose rapidly during 220~400癈 and overlapping many high polymer materials' decomposition temperature range and show good fireproofing compatibility with materials. The high carbon residue of about 30% at 600癈 shows that the compounds have good carbonization function.We applied the Compounds to alkyd resin varnish, epoxy resin (E ?44) and cotton cloth to test their flame resistance. Among the methods,the Level combustion method (GB2408-80) used in epoxy resin (E-44) and perpendicular combustion method (GB5455-97) used in cotten cloth are standard methods. Result indicates that the title compounds have good flame resistance. The compounds I ,~i give effect of self-extinguish in Is with 1% addition in alkyd resin varnish. Compounds with-OH have good dissolvability and give transparent and bright varnish coat with high addition. Compounds with-Cl give effect of self-extinguish in Is with 0. 5% addition, phosphorus and halogen in these compounds show cooperate fireproofing effect. Compounds I e~h can be used in cotton cloth as reactive flame retardant. The treated cloth gives good feel and can give self-extinguish effect after deviate from fire and has certain washing fastness. Compound I a~f have better flame resistance than others in epoxy resin (E-44). In the level combustion test, combustion length is less than 2 cm with a 10% addition. The samples foamed and expand during combustion process. They carbonize and extinguish after deviate from fire,without melting and dropping and with low smoking.Thermal analysis and initial fireproofing test show that the title compounds are promising intumescent flame retardants.