Development of SEP based coeffective flame retardant and its smoke suppression for EPDM.

Graphene and tannic acid were modified by magnetic agitation and ultrasonic dispersion. Modified graphene compounding with ammonium polyphosphate (APP) is prepared an expanded flame retardant system (AGT), which AGT was selected as the main flame retardant and sepiolite (SEP) as co-flame retardant in this work. Five modifiers including tannic acid (TA), oleic acid (YS), oleic acid amide (YSXA), thaumatin (TW) and oleyl amine (YA) were introduced to make modified SEP (SEP@M and M represents respectively TA, YS,YSXA,TW and YA). FTIR spectroscopy was performed on SEP modified by different modifiers at 1: 8, 1: 10, and 1: 15 ratios. The effect of modifier on the dispersion of SEP in Ethylene propylene diene (EPDM) adhesive and the optimum ratio of SEP modification were studied. Finally, the effect of the combination system on the flame retardant performance of EPDM/AGT/SEP@M composites was analyzed, and the smoke retardant mechanism of SEP coflame retardant and expansion flame retardant system in matrix materials was investigated. Experimental results showed that EPDM/AGT/SEP₈@YS₁ achieved a V-0 grade with an oxygen index of 44.92% compared to the blank control group. The thermal release rate of EPDM/AGT/SEP₈@YS₁ decreased by 49.8% and the smoke release rate and total smoke release rate decreased by 75.3% and 41.9%, respectively, compared to pure EPDM. In addition, the tensile and tear strength of EPDM/AGT/SEP₈@YS₁ was increased by 26.14% and 9.91%, respectively, compared to EPDM/AGT/SEP in mechanical properties. [ABSTRACT FROM AUTHOR]