两类无卤阻燃体系对mPE树脂基体阻燃和力学性能的影响

Effect of Two Halogen-Free Flame Retardant System on the Flame Retardant and Mechanical Properties of mPE Resin Matrix

以乙烯-辛烯共聚物(POE)及乙烯-醋酸乙烯酯共聚物(EVA)为增韧剂、马来酸酐接枝线型低密度聚乙烯(LLDPE-g-MAH)为增容剂,分别采用磷氮阻燃剂(PN)和纳米蒙脱土(nano-OMMT)、氢氧化铝(ATH)和氢氧化镁(MH)阻燃体系,利用双螺杆挤出和注射成型制备无卤阻燃茂金属聚乙烯(mPE)复合材料。测试并分析了PN/nano-OMMT/mPE、ATH/MH/mPE和PN/ATH/MH/mPE复合材料的热稳定性、阻燃和力学性能。结果表明,与mPE树脂基体相比,ATH/MH的热分解温度范围较大。PN/nano-OMMT的阻燃效率高于ATH/MH。当PN/nano-OMMT含量为50%时,PN/nano-OMMT/mPE的LOI为30.8%,垂直燃烧等级达到UL 94 V-0级;当ATH/MH含量由40%增大至70%时,mPE复合材料拉伸强度从10.86 MPa增大至12.48 MPa,断裂伸长率从539%下降至109%。在满足阻燃性能相同的条件下,PN/nano-OMMT/mPE的断裂伸长率高于ATH/MH/mPE,但拉伸强度较低。10%PN部分替代ATH/MH后,60%PN/ATH/MH/mPE的断裂伸长率和LOI均提高。

Halogen-free flame retardant metallocene polyethylene(mPE)composite were prepared by twin-screw extruder and injection molding using ethylene-octene copolymer(POE)and ethylene-vinyl acetate copolymer(EVA)as tougheners,maleic anhydride grafted linear low density polyethylene(LLDPE-g-MAH)as compatibilizer,phosphorus nitrogen(PN)and nano-montmorillonite(nano-OMMT),or aluminum hydroxide(ATH)and magnesium hydroxide(MH)as compound flame retardant system,respectively.Tested and analyzed the thermal stability,flame retardant and mechanical properties of the PN/nano-OMMT/mPE、ATH/MH/mPE and PN/ATH/MH/mPE composite.The results indicated that the thermal decomposition temperature range of flame retardant(ATH/MH)(260~512℃)completely covered the thermal degradation range of mPE resin matrix(430~500℃).PN/nano-OMMT had higher flame retardant efficiency compared with ATH/MH.When the content of PN/OMMT was 50%,the LOI of PN/nano-OMMT/mPE reached 30.8%,and the combustion grade was UL 94 V-0.The tensile strength of mPE composite increased from 10.86 MPa to 12.48 MPa,and the elongation at break decreased from 539%to 109%with increasing the ATH/MH content from 40%to 70%.Under the condition of satisfying the same flame retardancy,PN/nano-OMMT/mPE had higher elongation at break and lower tensile strength compared with ATH/MH/mPE.When 10%PN partially replaced ATH/MH,the elongation at break and LOI of 60%PN/ATH/MH/mPE were improved simultaneously.