碱性钙基膨润土协同卤锑阻燃HDPE的研究

【目的】解决卤锑阻燃高密度聚乙烯(HDPE)复合材料燃烧时发烟量大、熔融滴落严重等问题。【方法】采用自制的碱性钙基膨润土(Ca-MMT)与卤锑阻燃剂复配阻燃HDPE,通过极限氧指数(LOI)、水平燃烧等级、力学性能和热稳定性等测试,研究Ca-MMT和卤锑阻燃剂对HDPE的协同阻燃效应。【结果】HDPE/DBDPE/Sb2O3/Ca-MMT复合材料的LOI由纯HDPE的19.60%提高至32.77%,水平燃烧等级由HB75级提高至HB级,且燃烧时不产生熔滴,具有良好的成炭效应;拉伸强度由13.35MPa提高至23.33MPa,力学性能良好;失重率由纯HDPE的96.17%降至86.50%,热稳定性明显提高。碱性钙基膨润土的最佳添加量为4%。【结论】自制的Ca-MMT与卤锑阻燃剂有较好的协同阻燃作用。

The Flame Retarding Synergism of Alkaline Ca-Bentonite with Halogen-antimony Flame Retardants on HDPE

Objective] The halogen-antimony flame-retardant high-density polyethylene (HDPE) composites produced heavy smoke and serious combustion dripping during burning. Flame retarding synergism was explored to solve these problems.Methods] The modified alkaline Ca-bentonite (Ca-MMT) combining with halogen-antimony flame retardant was used to prepare HDPE compound flame retardant.The flame-retardant synergism of Ca-MMT and halogen-antimony flame retardant in HDPE composites were studied by means of limiting oxygen index (LOI), horizontal burning grade, the mechanical property and thermal stability tests.Results] The LOI of flame-retardant HDPE/DBDPE/Sb₂O₃/Ca-MMT composites increased from 19.60% of pure HDPE to 32.77%, horizontal flammability level was gradually improved from level HB75 to level HB, and the smoke and combustion droplet were not produced with a good char formation effect.Tensile strength increased from 13.24 MPa to 23.33 MPa, which testified that the material had good mechanical properties.Weight loss rate decreased from 96.17% of pure HDPE to 86.50%, which indicated that the thermal stability was improved in comparison with pure HDPE.The optimum adding amount of Ca-bentonite was 4%.Conclusion] The results showed that the synergistic flame retardant effect of Ca-MMT and halogen-antimony flame retardant was satisfactory.