The effect of organopalygorskite (OPGS), molybdenum sulfide (MoS₂), and magnesium hydroxide (MH) combinations on fire retardant and flammability characteristics of low‐density polyethylene/ethylene vinyl acetate (LDPE/EVA) blends was investigated using the limited oxygen index (LOI), horizontal burning test (UL‐94), and cone calorimeter measurements. The combination of OPGS with exfoliated MoS₂ nanosheets is employed to reduce the conventional hydroxide content and enhance the PE/EVA blend flame‐retardant properties with a notable improvement in mechanical and processing characteristics. The flame‐retardant properties of the composites were compared with a reference PE/EVA sample with 55 wt% of MH, which is commonly used for wire coating. The effect of each additive and the use of a maleated polyethylene (PEgMA) as a compatibilizing agent on PE/EVA flame‐retardant properties were analyzed. The results of the LOI and UL‐94 tests confirmed that the addition of OPGS combined with MoS₂ substantially increases the LOI value (26%) and reduces the burning rate (66%) and the pHRR (83%) compared with neat polymer blend and passes V‐0 rating during UL‐94 vertical test, which were very similar to the values obtained for the reference sample with higher MH content. In addition, the results indicate that the addition of these additives simultaneously increases the tensile modulus with mechanical properties even higher than the reference sample. Most important, the results indicated that these additive combination allows to reduce the total MH filler content to achieve the flame‐retardant requirements and with enhanced mechanical properties and with higher melt flow rates and lower viscosities facilitating the processing of the polymer composites at lower pressure in the processing extruder. Therefore, this additives combination provides a favorable way to obtain efficient flame‐retardant materials with halogen‐free, low smoke, and easy processing characteristics. J. VINYL ADDIT. TECHNOL., 26:434–442, 2020. © 2020 Society of Plastics Engineers

中文翻译：

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有机硅藻土和硫化钼的组合，可生产出机械和加工强度低，氢氧化镁含量低的阻燃PE / EVA共混复合材料

使用有限氧指数研究了有机坡缕石（OPGS），硫化钼（MoS ₂）和氢氧化镁（MH）组合对低密度聚乙烯/乙烯乙酸乙烯酯（LDPE / EVA）共混物的阻燃性和可燃性的影响（LOI），水平燃烧测试（UL‐94）和锥形量热仪测量。OPGS与脱落的MoS ₂的组合纳米片用于降低常规氢氧化物含量并增强PE / EVA共混物的阻燃性能，同时在机械和加工特性方面有显着改善。将复合材料的阻燃性能与参比的PE / EVA样品（含55 wt％的MH）进行了比较，该样品通常用于金属丝涂层。分析了每种添加剂的影响以及使用马来化聚乙烯（PEgMA）作为增容剂对PE / EVA阻燃性能的影响。LOI和UL-94测试的结果证实，加入OPGS和MoS ₂与纯聚合物共混物相比，大大提高了LOI值（26％），降低了燃烧率（66％）和pHRR（83％），并且在UL-94垂直测试中通过了V-0评级，这与该值非常相似MH含量较高的参考样品获得的结果。另外，结果表明，这些添加剂的添加同时增加了拉伸模量，其机械性能甚至高于参考样品。最重要的是，结果表明这些添加剂的组合可降低MH填料的总含量，从而达到阻燃要求，并具有增强的机械性能，较高的熔体流动速率和较低的粘度，从而有助于在低压下加工聚合物复合材料。加工挤出机。因此，这种添加剂组合为获得具有无卤素，低烟尘和易于加工特性的高效阻燃材料提供了一种有利的途径。J.乙烯基添加物。TECHNOL。，26：434–442，2020.©2020塑料工程师协会