纳米铁酸锌在软PVC中的阻燃性能研究

Study of flame retardant property of flexible PVC added with nano zinc ferrite

文章采用共沉淀法合成纳米铁酸锌，用X-Ray衍射仪、TEM对其进行表征。通过氧指数检测、热重分析及拉伸强度检测，考察了铁酸锌添加量对软PVC性能的影响。结果表明：采用共沉淀法合成的铁酸锌具有尖晶石结构，粒径为5～10nm铁酸锌添加量为2．5份时，软PVC试样氧指数由25．4％提高到29．7％，达到一般阻燃要求，明显地改善了软PVC试样的热分解性能，试样的最终残炭量由11．22％提高到20．69％；适宜的铁酸锌添加量，可以提高软PVC试样的拉伸强度和韧性。

Nano-sized zinc ferrite powder was prepared by the method of co-precipitation and its structure was characterized through X-ray diffractometer and TEM. The flame retardant property of flexible PVC treated with zinc ferrite was studied by oxygen index（OI）, differential thermal analysis, and tensile strength detection. The results show that the zinc ferrite prepared by the method of co-precipitation has the spinel structure, and the crystallite diameter is about 5-10 nm. The OI of flexible PVC added with 2.5 portions of zinc ferrite advances from 25.4% to 29.7%, which indicates that the flame retardant conforms to the general requirement for flexible PVC. The thermal degradation performance of flexible PVC added with zinc ferrite improves remarkably, and the final amount of residual carbon increases from 11.22% to 20. 69%. Besides, the appropriate added amount of zinc ferrite can improve the tensile strength and toughness of flexible PVC.