LDPE/滑石粉燃烧残余物的结构与隔热性及其对燃烧行为的影响

王勇1， 尚甜1,2， 程广森1， 高祯瑞1

（1.青岛科技大学 环境与安全工程学院，山东 青岛 266042；2.青岛市公安消防支队，山东 青岛 266071）

摘要： 燃烧残余物的隔热隔质作用是重要的阻燃机理，但其隔热隔质性能不易表征。以低密度聚乙烯（LDPE）/滑石粉为研究对象，以显微镜观察其燃烧残余物的微观形态，并以残余物受热后的上下表面温升来探讨其隔热性。研究发现，随着滑石粉填充量的增加，LDPE的燃烧热释放速率峰值不断下降，燃烧残余物厚度不断增加且隔热性不断提高。滑石粉质量分数低于10%时，残余物为表面含有大量微观孔穴的分散小薄片，薄片间的空隙和微观孔穴不利于其阻隔热量和质量传递。滑石粉含量达到20%时，小薄片相互连接形成整体并导致热释放速率峰值明显下降，但残余物较疏松。滑石粉含量达到40%后，残余物为较致密的多孔结构，表面微观孔穴也基本消失。

关键词： 低密度聚乙烯； 隔热性； 隔质； 燃烧残余物

 中图分类号： X 932；TQ 322                             文献标志码： A

 Influences of Structure and Heat Barrier Effect of Fire Residue on Burning Behaviors of Low Density Polyethylene/Talc Composite

 WANG Yong1, SHANG Tian1,2, CHENG Guangsen1, GAO Zhenrui1

(1.College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, China; 2.Qingdao Municipal Public Security Bureau Fire Department,Qingdao 266071, China)

Abstract: The fire residue which acts as the heat and mass insulators is very important to the flame retardancy. However, the heat and mass transfer properties of the fire residue are difficult to characterize. In this paper, the burning behaviors of the low density polyethylene (LDPE)/talc were studied. The fire residue was observed by the microscope and the heat barrier effects of the residue were analyzed by the temperature rise of its top and bottom surfaces under a given external heat flux. It was found that as the mass fraction of talc increased， the peak heat release rate decreased, the thickness and the heat barrier effect of the residue increased. If the mass fraction of talc was less than 10%， the residue were separated tablets with multiple microscale pores on surface. The gaps among tablets and the pores served as the routes of heat and mass transfer. If the content of talc reaches 20%， the tablets integrated into a whole block which would lead to decrease of the peak heat release rate significantly, but the residue was fragile. If the mass fraction of talc exceeded 40%， the pores started to disappear and the residue was cellular and compact.

Key words: low density polyethylene; heat insulation; mass insulators; residue of combustion

收稿日期： 20130803

基金项目： 国家重点基础研究计划（973）项目（2012CB724609）；国家自然科学基金项目（51306097）；山东省自然科学基金项目（ZR2012EMQ008）;青岛市科技计划基础研究项目（12143（26）jch）.

作者简介： 王勇（1979—），男，副教授.