Study On The Preparation And Properties Of Flame Retardant Semi-rigid Polyurethane Foams

Semi-rigid polyurethane foam(SPUF) plastic is commonly used as interiormaterials of automobile, industrial cushioning material and packaging material for itsexcellent performances. As a porous polymer, it’s easy to ignite and burn with smokeand toxic gases. It’s necessary to develop more efficient flame retardant and study themechanism. In this work, the flame retardant, thermal ability, mechanical propertiesand morphology of APP/SPUF, EG/SPUF,791/EG/SPUF and EG/APP/SPUF havebeen systematically studied. The main conclusions are as follows:One-component flame retardant research:1) According to the LOI and horizontalburning tests, APP is less effective than EG on interdicting the burning of SPUF.2)DSC and TG analysis indicates that the flame retardant does not affect the heatingeffect tendency of SPUF, but changes the position and intensity of exothermic peakand endothermic peak; The thermal decomposition product of APP, polyphosphoricacid, will catalyse the depolycondensation reaction of ammonia ester bond, andfinally decrease the thermal stability of SPUF, moreover, APP has certain effect on thegeneration of char. EG has no significant effect on the degradation process of SPUF,but it decreases the maximal rate of weight loss, increases the thermal stability and theresidues.3) According to the burned fire-retardants filled SPUF, compared with pureSPUF, APP/SPUF decreased the dropping phenomenon, but increased smoke, andfinally formed a porous carbonaceous char. EG/SPUF decreased smoke and droppingeffectively, and finally developed into a loose and lacunaris worm-like structurecarbonaceous char.4) Compared with APP/SPUF, the mechanical performance andmorphology of EG/SPUF have been damaged more obviously, but the properties asSPUF have not been changed. The research results of791/EG/SPUF shows: compared with EG/SPUF, thecompress strength and morphology of791/EG/SPUF have been improved, but theLOI value, thermal stability and residues have been decreased.The research results of EG/APP/SPUF shows:1) The combustion test and△LOI curve indicate that APP and EG used together in SPUF has good synergisticeffects on flame retardancy, when the ratio of EG: APP is5:1, the EG/APP/SPUFhas the largest LOI value28.6vol%.2) TG analysis shows, compared with APP/SPUF,the temperature of initial degradation, maximum mass loss rate and carbon residue at800℃of EG/APP/SPUF have increased; compared with EG/SPUF, the maximal rateof weight loss of EG/APP/SPUF significantly has decreased. The curve of△Mshowed that the addition of EG and APP to SPUF led to an increase in the amount ofhigh-temperature residue, and slowed down the process of polymer thermaldegradation.3) Compared with the burned residues of EG/SPUF and APP/SPUF,EG/APP/SPUF took the advantages of both, decreased smoke and droppingeffectively, and finally formed a compact worm-like structure and net carbonaceouschar.4) The mixture of EG and APP decreased the damage of EG only on themorphology of SPUF, such as uneven size, deformation and incomplete of bubblehole.