钢结构防火涂料烟气毒性定量分析研究

Quantitative Analysis of Smoke Toxicity of Fire Resistive Coating for Steel Structure

为研究钢结构防火涂料在火灾时的烟气毒性规律,通过NBS烟密度箱对四种钢结构防火涂料进行充分产烟,联用FTIR分析系统对烟气中CO、CO_(2)、HF、HCl、HBr、HCN、NOx和SO_(2)8种气体进行分析,采用常规毒性指数CITG定量评价烟气毒性。结果表明,一些溶剂性钢结构防火涂料在火灾中自身存在起燃风险;膨胀型钢结构防火涂料产生的烟气中主要有害气体为CO_(2)、CO、NOx和HCN;环氧树脂基膨胀型钢结构防火涂料的烟气毒性较其他树脂基的涂料要大,4 min时的CITG值达到0.369,8 min时的CITG值达到0.468;水基性钢结构防火涂料的烟气毒性明显小于溶剂性钢结构防火涂料。因此,在设计钢结构防火涂料配方时,除了要考虑钢结构防火涂料的耐火性能、耐候性和理化性能等,同时要考虑受火后的烟气毒性,合理选用成膜剂、发泡剂、成炭剂和阻燃剂等。

In order to investigate the smoke toxicity of fire resistive coating for steel structure in the event of fire,the smoke production was completely conducted on four types of steel structure fire resistive coatings using NBS smoke density boxes,and eight gases including CO,CO_(2),HF,HCl,HBr,HCN,NOx,and SO_(2)in smoke were analyzed using FTIR analysis system.The conventional toxicity index CITG was used to quantitatively evaluate the smoke toxicity.The results show that some solvent based fire resistive coating for steel structure pose a risk of ignition in fire.The main harmful gases in the smoke components of the intumescent fire resistive coating for steel structure are CO_(2),CO,NOx and HCN.The smoke toxicity of the epoxy resin-based intumescent fire resistive coating for steel structure is greater than that of other resin-based coatings,and the CITG value reaches 0.369 after 4 minutes and 0.468 after 8 minutes.The smoke toxicity of water-based fire resistive coating for steel structure is significantly lower than that of solvent based fire resistive coating for steel structure.Therefore,when designing the formula of fire resistive coating for steel structure,in addition to considering the fire resistance,weather resistance,and physicochemical properties,the smoke toxicity after being exposed to fire should also be considered,and film-forming agents,foaming agents,carbonizing agents,and flame retardants should be reasonably selected.