不同目数水菱镁石在PVC薄片中的应用

Discussion on Application of Different Mesh Hydromagnesite in PVC Sheet

通过多次机械研磨法制备的高目数水菱镁石粉(HM),添加到聚氯乙烯(PVC)的复合薄片中替代部分三氧化二锑(ATO),利用热失重仪、极限氧指数、烟密度测试箱等对该复合薄片的热稳定性、燃烧性能、抑烟性能等一些物理性能进行了研究。结果表明,此举不仅可以提高其热稳定性,对于最终残炭的质量也有一定程度的提升,更关键的是能够有效提升复合薄片燃烧进程中的抑烟性能,同时能够有效降低成本。高目数HM在粒径、比表面积和白度等方面均有明显的优势,添加进PVC复合薄片中,可以发现随着HM目数的增加,复合薄片的氧指数和抑烟效果均伴随着提升。通过扫描电子显微镜和拉曼光谱发现高目数HM能够有效提升残炭的致密和连续性,对于残炭的晶化程度也有一定的促进作用,此类结果表明高目数HM对于最终残炭的质量提升效果明显,能够有效改善炭层的物理阻隔效果,表明该高目数HM具备可替代部分ATO的潜力。与高目数氢氧化镁对比,HM在改善残炭质量方面效果更佳。

High mesh hydromagnesite powder(HM)was prepared via multiple physical grinding,which was utilized to replace part component of antimony trioxide(ATO)in the composite sheet of polyvinyl chloride(PVC).Several physical properties such as the thermal stabilities,combustion properties and smoke suppression performance of the composite sheet were studied by thermogravimetry,limiting oxygen index and smoke density test box.The results show that the thermal stability of PVC can be enhanced,the quality of final carbon residue can be improved to a certain extent.The smoke suppression performance can be improved significantly in the combustion process of composite sheet,and the cost can be also reduced.In particular,scanning slectron microscopy and Raman spectroscopy show that high mesh HM can effectively improve the density and continuity of carbon residue,the crystallization of carbon residue can be promoted to some extent.Such results indicate that high mesh HM can significantly improve the quality of final carbon residue,and the physical barrier effect of carbon layer can be improved as well.The high mesh HM has the potential to replace part of ATO.Finally,compared with the high mesh magnesium hydroxide,the quality of carbon residue can be improved by the HM more effectively.