Study On Preparation Of Polyester Polyol With High Phosphorus And Flame Retardant Epoxy Resin

Epoxy resins are widely used in the industrial field,but epoxy resins are flammable and can cause fires in applications.So the flame retardant modification of epoxy resins is also important.Phosphorus-based flame retardants have the advantages of being halogen-free,high-efficiency,and non-toxic,and their use to improve the flame-retardant properties of epoxy resins is one of the hot spots in the field of flame-retardant research.In this dissertation,Linear polyphosphate bishydroxymethyl phosphine oxide polyols flame retardant(LPHPOP)and hyperbranched polyphosphate bishydroxymethyl phosphine ester flame retardant(HPHPOE)were synthesized and used in epoxy resin flame retardant.Linear polyphosphate bishydroxymethyl phosphine oxide polyols flame retardant(LPHPOP)was synthesized from phenylphosphonic dichloride(BPOD)and bis(hydroxymethyl)methyl phosphine oxide(BMPO)and the experimental conditions were investigated.The synthetic route and process conditions were studied.The structure of LPHPOP was characterized by fourier transform infrared spectrometer(FT-IR);the curing process of LPHPOP/epoxy resin system was studied by differential scanning calorimetry(DSC).The thermal degradation kinetics of LPHPOP/epoxy resin system was studied by thermogravimetric analyzer(TGA).The morphology of residual carbon in LPHPOP/epoxy resin system was studied by scanning electron microscopy(SEM);the mechanical properties,thermal stability,and flame retardancy of LPHPOP on epoxy resin were studied.The results showed that with pyridine as the acid agent,0.1 mol(19.5 g)BPOD,and 0.15 mol(18.6 g)BMPO,the prepolymerization temperature was 50 ?,the reaction time was 50 min,The maximum yield was 91%.The resin has good carbon-promoting properties.When the addition amount is 20 wt%,the residual amount can reach 14.35%,which is 242%higher than that of the pure epoxy resin.Through Flynn-Wall-Ottawa and Coats-Redfern methods,The mechanism of thermal degradation kinetics of EP system was determined as Phase-dependent controlled reaction type.The kinetic mechanism of thermal degradation of EP-10 wt%LPHPOP system was 3-dimensional phase boundary reaction type;LPHPOP has a certain improvement on the mechanical properties of epoxy resin;when LPHPOP is added at 10 wt%,the LOI value of LPHPOP/epoxy resin system is increased from 19.6 to 29.7.A hyperbranched polyphosphate bishydroxymethyl phosphine ester flame retardant(HPHPOE)was synthesized from phenyl phosphorus oxychloride and bishydroxymethyl methyl phosphine oxide(BMPO),the experimental conditions were investigated.The synthetic route and process conditions were studied.The structure of HPHPOE was studied by FT-IR;the curing process and curing kinetics of HPHPOE/epoxy resin system were studied by differential scanning calorimetry(DSC);Thermogravimetric analyzer(TGA)was used to study the thermal stability of HPHPOE/epoxy resin system.The morphology of residual carbon in HPHPOE/epoxy resin system was studied by scanning electron microscopy(SEM);The mechanical properties,the effect of flammability and thermal stability of HPHPOE to epoxy resin materials were studied.The results showed that with triethylamine as the acid agent,0.1 mol(15.3 g)phosphorus oxychloride,0.2 mol(24.8 g)BMPO,the prepolymerization temperature was 40 ?,reaction time was 70 min,and the product yield was up to 92%.The reaction order single-parameter autocatalytic model well describes the curing reaction process of HPHPOE/epoxy resin system.HPHPOE has good carbon-promoting property to epoxy resin.When the adding amount is 20 wt%,the residual amount can reach 26.21%,which is 524%higher than that of pure epoxy resin.HPHPOE has a certain improvement in the mechanical properties of the epoxy resin.when HPHPOE is added at 15 wt%,the LOI value of the epoxy resin has been raised from 19.6 to 28.1.