Study On The Synthesis And Flame Resistance Of Novel Flame Retardants Containing Phosphorus And Nitrogen Moiety

In recent years, fire disasers were on the increase and made great property losses. In our country, in 1997, there were 140 thousand fire and 2722 fire deaths. Direct losses caused by fire added up to 1.54 billions. Fire disasers make great number of deaths and heavy property losses every year all over the world. Now people increasely realize that, treating inflammable materials with fire retardant is one of the strategic measures to prevent and decrease fire. Flame retardant material, especially flame retardant polymeric material, and flame retardant technology became research hotspot all over the world.Nitrogen-phosphorus compounds are a family of promising flame retardants, which have many advantages: they themselves and their gases or vapors evolved during combustion have low toxicity. Nitrogen-phosphorus compounds as flame retaedant has a positive prospect.1. Eight amide derivatives I a-h were synthesized by the substitute reaction of 1-oxo-l-phospha-2,6,7-trioxabicyclo[2.2.2]octane-4-acyl chloride withvarious amines.2. Compound 5,5-dimethyl-2-hydrazino-2-oxo-l,3,2-dioxaphosphorinane was synthesized by 5,5-dimethyl-2-chloro-2-oxo-1,3,2-dioxaphosphorinane and hydrazine hydrate for the first time. Then 8 novel title compounds,II a-h,were synthesized by 5,5-dimethyl-2-hydrazino-2-oxo-1,3,2-dioxaphos phorinane and substituted benzaldehydes.3. Ten novel title compounds, III-j, were synthesized by 5.5-dimethyl-2-chloro -2-oxo-1,3,2-dioxaphosphorinane and various amines.4. All the title compounds were confirmed by DR., 'H NMRx MS and elementary analysis.5. Applied the compounds to alkyd resin varnish to test their Flameresistance.All of the compounds give effect of self-extinguish in 1s with 1% addition in alkyd resin varnish.6. Applied the compounds to expoxy resin (E-44) to test their Flame resistance. Compounds IIIi and IIIj have better flame resistance than others in epoxy resin (E-44). Because they are more phosphorus-containing than that of the others. The amount of charred residue increases with increasing phosphorus content in a material. The formation of more compact charred crust surface with increasing phosphorus content in material.The samples foamed and expanded during combustion process. They carbonize and extinguish after deviate from fire, without melting and dropping and with low smoking.7. TG and DTA analysis of some of the compounds were discussed. Most of the compounds begin to decompose at 220 C and have certain thermal stability. They decompose rapidly during 220-400 C and overlapping many polymeric material' decomposition temperature ranger and show good fireproofing compatibility with materials.