Study On The Preparation And Flame Retardant Properties Of Ionic Liquid Modified Mining Polymers

The effects of four ionic liquids on the flame retardancy of flexible polyurethane?FPUF?composites were studied,and the best ionic liquid was 1-butyl-3-methylimidazole hexafluorophosphate?IL?.By using IL and silane coupling agent to modify graphene oxide?GO?,ionic liquid modified graphene oxide?ILGO?containing phosphorus,fluorine and silicon was successfully prepared,which was used in flexible polyurethane?FPUF?,unsaturated polyester resin?UPR?and epoxy resin?EP?,and the thermal stability,flame retardancy and flame retardance mechanism of composite materials were analyzed by limiting oxygen index?LOI?,vertical combustion test?UL-94?,thermogravimetric test?TG?and cone calorimetry test?CCT?methods.The main content conclusions are as follows:1?Screening study on the flame retardance of FPUF by four different ionic liquids.The ionic liquid?1-butyl-3-methylimidazole hexafluorophosphate,1-ethyl-3-methylimidazole tetrafluoroborate,1-ethyl-3-methylimidazole phosphate diethyl ester,and tetrapropylamine tetrafluoroborate?were added to the flame retardant FPUF system.By the LOI and flame retardant efficiency?EFF?,1-butyl-3-methylimidazole hexafluorophosphate was optimizated to be the best one,whose LOI is 27.5%,the EFF is 0.54.TG and CCT results showed that ionic liquid containing fluorine and phosphorus could enhance thermal stability,reduce mass loss,and have effective flame retardancy.2?The results of FTIR,XRD,TEM,and SEM-EDS showed that ionic liquid containing fluorophosphate was successfully loaded on the GO surface by the silane coupling method,and the interlayer spacing of the ILGO nanomaterials was further increased.TG results showed that the residual carbon content of GO at high temperature is 4.0%,while the residual carbon content of ILGO is 48.2%,which proved that the thermal stability of ILGO is significantly higher than that of GO.3?The synergistic flame retardant effect between ILGO?GO?and APP/EG was studied in FPUF composites.The LOI results showed that when the mass ratio of the flame retardant is 7.5:7.5:0.05,LOI increases to 29.0%?FPUF-4?.The water resistance results showed that the FPUF with GO increased by 59.89%compared with the pure sample,and the water absorption with FPUF-4 decreased by 7.76%compared with FPUF-3.TG showed that compared with pure samples,T_iof the FPUF with GO and ILGO decreased by 6.4%and 8.7%,T_maxdecreased by 6.3%and 5.9%,and the residual carbon content increased by 50.5%and 58.1%,respectively.CCT tests showed that compared to pure samples,the PHRR of FPUF-4 decreased by70.9%,THR decreased by 56.4%,TSP decreased by 82.7%,residual carbon increased by 418.7%,and CO₂production rate decreased by 71.9%.It indicated that ILGO enhanced the denseness of the"worm-like"carbon layer and better blocked the gas and heat,reduced the heat release rate,suppressed the release of toxic gases,improved the flame retardancy and thermal properties of FPUF,and reduced fire risk.4?The synergistic flame retardant effect between ILGO?GO?and APP/EG was studied in UPR composites.When the total amount of flame retardant is 9%,the optimal ratio of APP:EG:GO?ILGO?is 7.5:2.5:0.1,the LOI of UPR-4 with ILGO reached 28.2%and UL-94 reached V-0,SE is 1.68.The TG analysis showed that the amount of carbon remaining in UPR-4 with ILGO increased significantly,and UPR-4increased by 26%and 22%compared with UPR-2 and UPR-3,respectively.CCT tests showed that compared to pure UPR,the PHRR of UPR-4 reduced by 47.3%,THR reduced by 22.2%,SPR reduced,CO₂generation rate reduced by 53.9%,the amount of remaining carbon increased by 44.6%,and the fire performance index is 0.633,the fire spread index is 1.102,the smoke parameter is 155.048.The above results showed that the synergistic effect of ILGO,APP and EG on flame retardant and smoke suppression of flame retardant UPR composites is significant.5?The synergistic flame retardant effect between ILGO?GO?and MPP was studied in EP composites.According to the results of LOI,MPP has the best flame retardant effect,and the optimal addition amount was 15%.The LOI of EP with ILGO increased by 4.3%compared to EP-MPP-GO,and UL-94 reached V-0.Compared with EP-MPP,the tensile strength of EP-MPP-GO and EP-MPP-ILGO increased by15.6%and 28.3%,and the tensile strain at break increased by 9.8%and 5.0%,respectively.TG showed that EP-MPP-ILGO had better carbon formation effect,and the residual carbon ratio increased by 14.4%compared with EP-MPP-GO.CCT results showed that compared to pure EP,the PHRR of EP-MPP-ILGO decreased by95.4%,THR reduced by 89.7%,TSP decreased by 95.8%,the peak of CO and CO₂production rates were reduced,but the average production increased by 200%and57%,the average effective heat combustion reduced by 23.2%,and the fire performance index is 17.31,the fire spread index is 0.06,the smoke parameter is164.36.It showed that the addition of ILGO to EP has the effect of reducing heat and smoke and increasing fire safety.According to SEM analysis,the adhesion between IL and GO can be formed,which can better synergize with MPP to obtain good flame retardant EP composites.After combustion,a good protective carbon layer can be formed,which can effectively improve fire safety of EP composites.In summary,when IL is used as a synergistic flame retardant alone,it has a good flame retardant and smoke suppression effect on FPUF composites;The ILGO is prepared by IL and GO,as a synergist in a small amount complexed with different traditional flame retardants,is applied to thermosetting polymer materials to achieve better flame retardant and smoke suppression effects.