聚氨酯保温材料人工加速湿热老化性能研究  

Aging properties of polyurethane insulation materials at the accelerated hydro-thermal aging environment

作　　者：邓蕾[1] 杨晖[1] 程旭东[1] 

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,合肥230027

出　　处：《安全与环境学报》2014年第3期49-53,共5页Journal of Safety and Environment

基　　金：国家重点基础研究发展计划(973计划)项目(2012CB719701)

摘　　要：采用恒温恒湿箱，在60℃、90% RH条件下对聚氨酯保温材料进行人工加速湿热老化，并通过扫描电子显微镜、傅里叶变换红外光谱、热重分析试验对其老化性能进行研究。结果表明，随着老化时间的增加，泡孔结构逐渐受到破坏，样品尺寸呈增大趋势，质量逐渐减小，老化至96 d时，较老化前的样品面积增加了1.48%，质量减小了4.79%。随着人工加速湿热老化试验的进行，氨基甲酸酯指数逐渐下降，由最初的3.284下降为2.619，表明湿热老化会引起聚氨酯保温材料氨基甲酸酯基水解，导致材料老化。聚氨酯保温材料湿热老化前后主要有4个失重阶段，通过Inflection Point方法计算得到第2和第3失重阶段的热解活化能差异百分比分别为1.49%-2.0%与2.43%-6.33%，表明湿热老化对聚氨酯保温材料的热降解机理没有显著影响。The paper intends to present our experimental investigation results over the stability of the polyurethane insulation materials when stored or used in the hot and humid environment. Our experiments with the polyurethane insulation materials were conducted at 60℃, 90% RH in a condition of Humidity Chamber, in hoping to test the effects of aging on the properties of polyurethane foam by means of scanning electron microscopy （SEM）, Fourier Transform Infrared Spectroscopy （FTIR） and the thermo-gravimetric （TG） analyzer. The results of our research have shown that： with the increase of the aging time, gradual change, loss or damage prove to have happened with the foam structure. For example, the sample size would be increased, but its weight tends to get lowered. Statistically speaking, when aging to 96 days, rupture and collapse were found taking place with the cellular structure in a large area. In comparison with the unaged samples, the size of the area was found increased by an average of 1.48%, whereas the mass would be decreased by 4.79%, though IR spectra of different aging stages didn＇t change noticeably. Thus, this paper intends to define the absorption peak area ratio of carbamate to benzene ring as the carbamate index, which can be used to indicate the change of the carbamate relative concentration. With the aging experiment going on to the above said period of time, the carbamate index turned to drop from^3.284 to 2.619, which demonstrates that it is the hygrothermal aging process that has caused the hydrolysis of carbamate group, and thus bringing polyurethane insulation material to the aging state in-situ. The thermo-gravimetric rate curve proves that the degradation of unaged and aged polyurethane insulation materials can be identified in four stages. At the first stage, the degraded loss of the material in the aging process would cause the maximum mass losing rate to decrease with the aging time, whereas in the second and third stages, it would be possible to use the Inflection Point

关 键 词：安全工程 聚氨酯 保温材料 湿热老化 老化行为 

分 类 号：TU532.4[建筑科学—建筑技术科学]