Study On Synthesis And Application Of Organic Phosphorous Flame Retardant

Dithiopyrophosphorate is a kind of effective and classic blending flame retardant used inviscose fibre. It is synthesized in two steps of reaction. First intermediate is prepared frompentaerythritol and thiophosphoryl chloride, which is reacted with water, then the targetproduct is prepared. The route makes manufacture technics complex and increases cost ofproduction. The paper improve on synthesis technics by selection of solvent,acid bindingagent, used toluene as solvent, triethylamine as acid blending agent. The route is one-potreaction without isolation of intermediate. The yield is 82%, the recovery of solvent and is85% and the recovery 80% respectively. The one-pot reaction route reduces production costand achieves domestic industrialization. The flame retardancy is good.Desides, based on hotspot of organic phosphorous flame retardant, the paper designs andsynthesizes three polyphosphate esters flame retardant and two caged bicyclic phosphateflame retardant.Intermediate pentaerylthritol diphosphonate dichloride (PDD) is synthesized frompentaerylthritol and phosphorus oxychloride. Quinol, resorcin, bisphenolA are reacted withPDD respectively, three polyphosphate esters are prepared in total yield of 60%, 53%, 67% inturn. The structure is characterized by NMR and IR. Polymerization degree is calculated byintegral in ³¹p NMR, 6.5, 12, 14.5 in turn. The thermal behaviors are studied by TGA andDSC, three polyphosphate esters all have excellent thermal stability and char formingcharacteristics.Tri(1-oxo-2,6,7-trioxa-1-phosphabicyclo[2,2,2]octane-methyl)phosphate is synthesizedfrom pentaerylthritol and phosphorus oxychloride, tri(1-thio-2,6,7-trioxa-1-phosphabicyclo[2,2,2]octane-methyl)phosphate is synthesized from pentaerylthritol and thiophosphorylchloride. The yield of two caged bicylic phosphate is 70%, 55% respectively. The structureand thermal behaviors are characterized and studied by NMR, IR, TGA and DSC respectively.Two caged bicyclic phosphates both have excellent thermal stability and char formingcharacteristics.