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典型湿式建材中VOC的散发特性研究
Study on the Characteristic of VOC Emission from Typical Wet Building Materials
【作者】 陈静;
【导师】 朱能;
【作者基本信息】 天津大学 , 供热、供燃气、通风及空调工程, 2012, 博士
【摘要】 随着人们生活水平的提高,对室内的装饰要求也越来越高。因此,各种湿式建材在室内得到广泛的应用。但是,很多湿式建材会向室内空气中释放醛类、芳香烃、酮类、酯类等挥发性有机物,严重的污染了室内空气。商场、超市、现代化教学楼等公共场所内通常具有高级的内部装修、密集的人群、各式各样的商品,这类场所空气中的有机污染更加复杂。因此,本文展开如下研究。采用指触法和刀片法研究了23℃、33℃、43℃时,聚氨酯清漆、水泥地面漆漆膜的干燥时间。同时,还测量这3组温度下,这2类湿漆膜干燥过程中的光泽度变化情况。利用溶剂稀释、针筒滤膜过滤等前处理方法,以及气相色谱–质谱联用技术对3种溶剂型漆和5种粘贴性胶粘剂中的挥发物进行定性。同时,还利用傅立叶变换红外光谱技术对这几类湿建材中的基料和助剂进行鉴定。以美国材料试验协会、欧洲标准化委员会制定的D5116–97、EN ISO16000-9为主要依据,设计了小型环境舱测试系统。对系统的组成、测试舱的内部结构、实验前的准备、实验过程都进行了详细介绍。在小型环境舱内,进行33℃、43℃条件下,以饰面三合板、混凝土板为载体时,聚氨酯清漆和水泥地面漆漆膜中VOC的短期散发实验。对环境舱内苯系物、烷烃、乙酸丁酯、TVOC的气相浓度随时间的变化规律进行说明。同时,还分析了温度对这2类溶剂型漆中VOC散发的影响。利用小型环境舱测试系统,研究无地毯、粘贴4种地毯的条件下,以混凝土板为载体时,绿叶王万能胶和新凯力万能胶散发的VOC浓度随时间的变化情况。定量检测的污染物为:1,2-二氯乙烷、2-甲基己烷、3-甲基己烷、乙酸甲酯、甲苯、TVOC。重点分析整个实验过程中(24小时),地毯对这几类VOC气相浓度的衰减作用,以及对峰值出现时间的影响。以胶粘剂在实际中的应用为基础,建立由空气层、表面装饰层、胶粘剂层和载体层组成的VOC散发模型。采用欧拉法和4点差分格式对模型进行离散,利用迭代法求解。分析了模型各层中的乙酸乙酯浓度随时间的变化情况。同时,还讨论了表面装饰层内的扩散系数D3a,对各层内乙酸乙酯浓度的影响。最后,利用分光光度法、溶剂解吸-气相色谱法对天津地区某大型超市和某教学楼内空气中的甲醛、苯、甲苯浓度进行检测。重点对超市内不同销售区空气中的污染物浓度进行比较。
【Abstract】 With the development of the living standard, the requirement of indoor decorationhas become higher and higher. Therefore, many kinds of wet building materials arewidely applied indoors. However, some wet building materials release aldehydes,aromatic hydrocarbons, ketones, esters and other volatile organic compounds toindoor air, and cause serious indoor organic pollution. High-grade interior decoration,a thick crowd and various goods are common in the shopping malls, supermarkets,modern classroom buildings and other public places, so the organic pollution inindoor air of these places are more complex. Therefore, this paper carries on thefollowing research.The drying time of the coating film of polyurethane varnish and cement floorpaint were measured at three groups of temperature (23°C,33°C and43°C) throughthe finger contact method and the blade method. At the same time, the changes ingloss of these two wet coating film during the drying process were investigated underthese three temperatures.The volatile organic compounds (VOC) from three kinds of solvent-based paintand five types of adhesive had been identified by the pretreatment including solventdilution, ultrasonic extraction and filtration, and gas chromatography-massspectrometry analysis. The film-forming materials and auxiliary agents in these paintand adhesive were also determined by Fourier-transform infrared spectroscopy.A small environmental chamber testing system were designed on the basis of D5116–97and EN ISO16000-9formulated by the American Society for Testing andMaterials and European Committee for Standardization, respectively. The components,interior structure of the test chamber, preparation before experiments andexperimental process were described in detail.The short-term emission of organic compounds from the polyurethane varnishfilm and cement floor paint film were carried out in the small environmental chamberat two temperatures (33°C,43°C). These two paints were applied to beech plywoodsand concrete slabs, respectively. The gaseous concentration versus time for thebenzene series, alkanes, butyl acetate, TVOC were described during24-h experiment. The effect of temperature on VOC emission from these two coatings were alsoanalysed.In the small chamber, VOC emission from two kinds of solvent-based adhesivespread on concrete slabs were investigated under the conditions of no carpt and4kinds of carpet on the surface of adhesive film.1,2-dichloroethane,2-methylhexane,3-methylhexane, methyl acetate, toluene and TVOC were selected as targetcompounds for quantitative analysis in the experiment. The influence of carpets on theattenuation of gaseous concentrations and the time of reaching peak concentrationwere specified during24h exposure.According to the application of adhesive in practice,a VOC emission model wasdeveloped. This model consisted of the air layer, covering layer, adhesive layer andsubstrate layer. The Euler method and four points difference scheme was adopted todiscretize the model, and then the iteration method was used to solve the discreteequations. The concentration change of ethyl acetate with time in each layer of themodel were analyzed. The influences of diffusion coefficient in covering layer onthe ethyl acetate concentrations of different layers were also discussed.Finally, concentrations of formaldehyde, benzene and toluene in the air in a largesupermarket and a classroom building in Tianjin were measured with the methods ofspectrophotometric method and solvent desorption-gas chromatography.Concentrations in different sales areas of the supermarket were compared at length.
【Key words】 wet building materials; drying time; VOC; concentration; emissionmodel;