To prepare expandable graphite (EG) with high anti-flame property to Linear low density polyethylene (LLDPE), dosages of oxidant KMnO4, intercalation reagent H2SO4 and ancillary intercalation reagent (NH4)3PO4 were optimized during oxidation intercalation reaction of natural graphite. With the lower initial expansion temperature (To) and higher expanded volume (EV) as the selected standard in L9(34) orthogonal test, suitable preparation condition of EG was confirmed as C : KMnO4 : 96%H2SO4 : (NH4)3PO4 = 1 : 0.2 : 3.0 : 0.45. The reaction lasts In at 40℃ with H2SO4 is dulited to a mass fraction of 75%, then EG with a low To of 165 ℃ and high EV of 400 Ml/g is obtained; the addition of 30% EG sample can make LLDPE's oxygen index increase to 25.7% compared with the oxygen index 21% of 30% APP for LLDPE. While, the addition of 20% EG sample and 10% APP can make LLDPE's oxygen index increase to 27.8%. Oxygen index test indicated that the prepared EG has higher anti-flame capability to LLDPE.%以制备对线性低密度聚乙烯( LLDPE)具有高阻燃特性的可膨胀石墨(EG)阻燃剂为目的,以其较低的起始膨胀温度和高膨胀性能为优化目标,筛选出天然鳞片石墨氧化插层反应中氧化剂高锰酸钾、插层剂硫酸、辅助插层剂磷酸铵的适宜配比为C:KMnO4:96％H2SO4:(NH4)3PO4 =1:0.2:3.0:0.45,质量分数为96％硫酸需稀释至75％,在温度40℃下反应1h,可以制得起始膨胀温度165℃、膨胀容积为400 mL/g的EG；添加30％的该可膨胀石墨可以使LLDPE的氧指数提高到25.7％(添加30％聚磷酸铵(APP)的氧指数为21％),而20％ EG协同10％ APP阻燃LLDPE氧指数可提高至27,8％,说明制得的可膨胀石墨具有较好的阻燃性能.
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