无卤阻燃EVA电缆专用料的配方优化

Optimizing Formula of Special Halogen-Free Flame Retardant EVA Cable Compound

通过基体树脂复配、自制相容剂(E-g-M)增容以及E-g-M与三元乙丙橡胶(EPDM)并用等途径对乙烯-醋酸乙烯酯共聚物(EVA)/氢氧化镁(MH)/微胶囊化红磷(RP)无卤阻燃电缆料(EMP)性能进行了优化。结果表明:EVA与高密度聚乙烯(HDPE)复配可有效提高EMP电缆料的拉伸强度,EVA与HDPE的质量比为3∶1时,EMP/HDPE电缆料的拉伸强度可由7.2 MPa提高到9.7 MPa;当在EMP/HDPE电缆料中添加12份E-g-M时,EMP/HDPE电缆料的拉伸强度由9.7 MPa增至12.8 MPa,冲击强度由26.5 kJ/m2升至29.4 k J/m2,断裂伸长率由63.7%增至97.8%,E-g-M对EMP/HDPE电缆料起到了同时增强、增韧的作用;当EMP/HDPE/E-g-M电缆料中加入5份EPDM时,EMP/HDPE/E-g-M电缆料的韧性得到了进一步提高,冲击强度和断裂伸长率分别增至35.8 kJ/m2和162.2%,并且两者的加入对EMP电缆料的拉伸性能、阻燃性能及加工性能影响较小。对照低烟无卤阻燃护套料的技术性能标准(YD/T1113—2001),EMP/HDPE/E-g-M/EPDM电缆料的力学性能和阻燃性能均高于该标准。

The properties of halogen-free flame retarding ethylene-vinyl acetate （EVA）/magnesium hydroxide （MH）/microencapsule red phosphorus （RP） cable compound （EMP） were optimized through mixing of matrix resins, self made compatibilizer （E-g-M） and cooperating E-g-M with ethylene propylene diene monomer （EPDM）. The result showed that mixing EVA with high density polyethylene （HDPE） could improve the tensile strength of EMP. When the mass ratio of EVA and HDPE was 3： 1, the tentile strength of EMP/HDPE cable compound could increase from 7.2 MPa to 9.7 MPa. Adding 12 phr E-g-M to EMP/HDPE cable compound, the tensile strength of EMP/HDPE cable increased from 9.7 MPa to 12. 8 MPa, the impact strength increased from 26.5 kJ/m^2 to 29.4 kJ/m^2, the elongation at break raised from 63.7% to 97.8%, which demonstrated E-g-M had a role of enhancing the strength and toughness of cable at the same time. When adding 5 phr EPDM to EMP/HDPE/E-g-M, the toughness of the cable compound had further improvment, its impact strength and the enlongation at break increased to 35.8 kJ/m^2 and 162. 2%, respectively. Cooperating E-g-M with EPDM had slightly influence on the tensile strength, flame retardant performance and processability of EPM cable compound. Compared with the standard of low smoke halogen-free flame retardant cable compound, the mechanical properties and flame retardant performance of EMP/HDPE/E-g-M /EPDM cable compound were all higher than those of the standard of YD/T 1113-2001.