Design,Construction Of Functional Carbonmicrosphere And Itsapplication In Flame Retardant TPU

In this paper,carbon microspheres(CMSs)and functionalized carbon microspheres(CMSs-Fe,CMSs-Cu,CMSs-Zn,CMSs-Y)were synthesized using glucose as raw material by hydrothermal method,and they were mixed with TPU by solution blending method into TPU/carbon microspheres,TPU/functionalized carbon microspheres masterbatch.TPU/carbon microspheres,TPU/functionalized carbon microspheres masterbatch and ammonium polyphosphate(APP)were used as flame retardant to mix with TPU by melt blending method to obtain flame retardant TPU composites.The flame retardant and smoke suppression performance and thermal stability of TPU composites were measured by Cone Calorimeter(CCT),Thermogravimetric Analysis(TGA),Thermogravimetric-Infrared(TG-IR),and the carbon residues were characterized by SEM,EDS,Raman spectroscopy.CCT results showed that compared with pure TPU,the peak heat release rate(pHRR)of CMSs0.25 decreased by 71.3 %,and the peak smoke release rate(pSPR)decreased by 63.4 %.While in TPU/APP/CMSs-Fe,TPU/APP/CMSs-Cu,TPU/APP/CMSs-Zn,TPU/APP/CMSs-Y systems,the functionalized carbon microspheres all exhibit excellent flame retardant and smoke suppression effects.Compared with pure TPU,pHRR of CMSs-Fe0.25 decreased by 70.4 %,total heat release rate(THR)decreased by 52.3 %,total smoke release rate(TSR)decreased by45.5 %;pHRR of CMSs-Cu0.5 decreased by 72.8 %,pSPR decreased by 66.3 %,TSR decreased by 45.4 %,and the peak CO release decreased from 0.034 % to0.018 %;pHRR of CMSs-Zn0.25 decreased by 69.1 %,THR decreased by 51.1 %,and pSPR decreased 66.4 %,TSR decreased by 63.8 %;pHRR of CMSs-Y1 decreased by 68.7 %,THR decreased by 73.2 %,pSPR decreased by 61.4 %,TSR decreased by 64.7 %,carbon residue quality increased from 12.3 % to 67.1 %.TG results showed that carbon microspheres and functionalized carbon microspheres canimprove the thermal stability of TPU/APP system and the ability of crosslinking to form carbon,which effectively increases the remaining carbon residue quality of TPU system;TG-IR results showed that TPU composites containing carbon microspheres or functionalized carbon microspheres releaseed less smoke precursors during thermal decomposition.The observation results of carbon residue showed that carbon microspheres and functionalized carbon microspheres can improve the density of the carbon layer,improve the structure of the carbon layer,and increase the strength of the carbon layer.