Preparation And Characterization Of Biodiesel-based Flame Retardant Materials

With the acceleration of urbanization,more and more sky-scrapers are being built.But the fire rescue of sky-scrapers is very difficult,once they catch fires,and people's lives and property are seriously threatened.On the other hand,the increasing population generates a large amount of edible waste oil?commonly known as“gutter oil”?everyday,and it is often directly poured into the urban sewage system,which pollutes our environment and wastes resources.If gutter oil is properly treated and further developed into other useful products,it not only reduces environmental pollution,save resources,but also reduces the risk of gutter oil flowing into our dining table.Therefore,in this study,gutter oil was used as feedstock and successfully prepared into a flame retardant rigid polyurethane foam with excellent performance.The main research work and results are summarized below.1.The compositions of GOB were tested by GC-MS,it mainly comprised methyl oleate and methyl linoleate.The content of unsaturated fatty acid methyl ester was about88.78%of the total fatty acid methyl ester.The calculated average molecular weight of GOB was 294.22.According to GB/T5530-2005,the acid value of GOB was determined to be 0.56 mg KOH/g.By GB/T12008.3-2009,the hydroxyl value of GOB was measured to be 4.29 mg KOH/g.Following GB/T 5532-2008,the iodine value of GOB was detected to be 124 g I₂/100g.It could be seen that the acid value was low and the iodine value was very high.GOB met the requirements of the experimental materials.2.By single factor and orthogonal experimental analyses,the results showed that the obtained epoxy gutter oil-based biodiesel?EGOB?had an epoxy value of 5.56%and an epoxy conversion rate of 80.03%under the optimized conditions:with no solvent,the rotation speed at 500r/min,the reaction temperature at 50?,the mass ratio of GOB,30%hydrogen peroxide,88%formic acid and concentrated sulfuric acid at15:13.5:2.9:0.075,and the reaction time at 3.5 h.Meanwhile,GOB and EGOB was characterized via FT-IR and ¹H-NRM,it could be known that C=C bonds in GOB had been broken and epoxy bonds formed.3.The conditions for the synthesis of flame retardant gutter oil-based biodiesel polyol?FRGOBP?were further optimized through single factor and orthogonal experimental analyses.The obtained optimized conditions were:the molar ratio of epoxy groups of EGOB to hydroxyls of three alcohols at 1:7.5,and the hydroxyl molar ratio of ethylene glycol,glycerin and flame retardant FRC-6 at 1:1:1,catalyst loading at 1.5%of mass EGOB,dichloromethane as solvent,the rotation speed at 1000 rpm/min,water as coolant,the reaction temperature at 65?,and the reaction at 50 min,and under which the hydroxyl value of FRGOBP was 143.7 mgKOH/g.By using infrared characterization,FRC-6 had been confirmed to insert into the epoxy groups of EGOB to form FRGOBP,but some epoxy groups remained in EGOB.4.Using FRGOBP,N,N-bis?2-hydroxyethyl?aminomethylenephosphonic acid diethyl ester?FRC-6?as reactive flame retardant,aluminum hydroxide?ATH?as additive flame retardant,the effect of ATH addition on the properties of flame retardant rigid polyurethane foam?FRRPUF?was explored.With the increase of ATH,the color of FRRPUF gradually changed from yellow to white,and its flame retardant performance became better and better.However,if too much ATH was added,the flame retardant performance of FRRPUF was not improved any more and inversely caused waste of raw material.The effect of FRC-6 addition?could also be seen as the amount of FRGOBP added?on the performance of FRRPUF was also investigated.It was found that the color of FRRPUF changed from white to yellow with the increase of FRC-6 addition,and the flame retardant performance was first enhanced and then reduced,and the foam became more brittle.Whether adding ATH or FRC-6,the thermal decomposition of FRRPUF basically showed three stages.With the increment of addition of ATH or FRC-6,the unresolved residue of FRRPUF increased,and the undecomposed residue was a residual carbon layer.When FRRPUF burned,the residual carbon layer would cover the surface of FRRPUF,preventing oxygen and heat from invading into the inner of FRRPUF,thus leading to a flame retardant effect.Through the burning test of FRRPUF,the temperature difference between the burning surface and the opposite surface was preliminarily tested.It was found that the temperature of the opposite surface was at less 700?lower than that of the burning surface,indicating that RRPUF had a very low thermal conductivity and showed a prosperous prospect in the application in fire insulation materials.