Silva Gabriela V, Vasconcelos M Teresa S D, Santos Armando M, Fernandes Eduardo O
LAQUIPAI, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
Environ Sci Pollut Res Int. 2003;10(4):209-16. doi: 10.1065/espr2002.12.144.
BACKGROUND, AIMS AND SCOPE: The building materials are recognised to be major contributors to indoor air contamination by volatile organic compounds (VOCs). The improvement of the quality of the environment within buildings is a topic of increasing research and public interest. Legislation in preparation by the European Commission may induce, in the near future, European Union Member States to solicit the industries of paints, varnishes and flooring materials for taking measures, in order to reduce the VOC emissions resulting from the use of their products. Therefore, product characterisation and information about the influence of environmental parameters on the VOC emissions are fundamental for providing the basic scientific information required to allow architects, engineers, builders, and building owners to provide a healthy environment for building occupants. On the other hand, the producers of coating building materials require this information to introduce technological alterations, when necessary, in order to improve the ecological quality of their products, and to make them more competitive. Studies of VOC emissions from wet materials, like paints and varnishes, have usually been conducted after applying the material on inert substrates, due to its non-adsorption and non-porosity properties. However, in real indoor environments, these materials are applied on substrates of a different nature. One aim of this work was to study, for the first time, the VOC emissions from a latex paint applied on concrete. The influence of the substrate (uncoated cork parquet, eucalyptus parquet without finishing and pine parquet with finishing) on the emissions of VOC from a water-based varnish was also studied. For comparison purposes, polyester film (an inert substrate) was used for both wet materials.
The specific emission rates of the major VOCs were monitored for the first 72 h of material exposure in the atmosphere of a standardized test chamber. The air samples were collected on Tenax TA and analysed using thermal desorption online with gas chromatography provided with both mass selective detection and flame ionisation detection. A double exponential model was applied to the VOC concentrations as a function of time to facilitate the interpretation of the results.
The varnish, which was introduced in the test chamber 23 h after the application of the last layer of material, emitted mainly glycolethers. Only primary VOCs were emitted, but their concentrations varied markedly with the nature of the substrate. The higher VOC concentrations were observed for the parquets of cork and eucalyptus, which indicated that they have a much higher porosity and, therefore, a higher power of VOC adsorption than the finished pine parquet (and polyester film). The paint was introduced in the chamber just after its application. Only primary VOCs were emitted (esters, phthalates, glycolethers and white spirit) but some compounds, like 2-(2-butoxyethoxy)ethanol and diethylphthalate, were only observed for paint/polyester, which suggested that they were irreversibly adsorbed by the paint/concrete. Compared with the inert substrate, the rate of VOC emissions was lower for concrete in the wet-stage (first hours after the paint application) but slightly higher later (dry-stage) as a consequence of desorption.
As to varnish, the substrates without finishing, like cork and eucalyptus parquets, displayed a higher power of adsorption of VOCs than the pine parquet with finishing, probably because they have a higher porosity. As concerns paint, the total masses of VOCs emitted were lower for concrete than for polyester, indicating that concrete reduces the global VOC emissions from the latex paint. Concrete is seen to have a strong power of adsorption of VOCs. Some compounds, namely 2-(2-butoxyethoxy)ethanol, diethylphthalate and TEXANOL (this partially), were either irreversibly adsorbed by the concrete or desorbed very slowly (at undetected levels). A similar behaviour had not been reported for gypsum board, a paint substrate studied before.
The present data suggest that concrete may be a recommendable substrate for paint in an indoor environment. As the nature of the substrate conditions the rate and nature of VOC emissions from wet materials, it must be explicit when emissions from composite materials are reported, in order to allow comparisons and labelling of the product in terms of indoor air quality.
背景、目的和范围：建筑材料被认为是挥发性有机化合物（VOCs）造成室内空气污染的主要来源。改善建筑物内的环境质量是一个研究和公众关注度日益提高的话题。欧盟委员会正在制定的法规可能会在不久的将来促使欧盟成员国要求油漆、清漆和地板材料行业采取措施，以减少其产品使用过程中产生的VOC排放。因此，产品特性以及环境参数对VOC排放影响的信息对于提供基础科学信息至关重要，这些信息能让建筑师、工程师、建筑商和建筑业主为建筑居住者提供健康的环境。另一方面，建筑涂料生产商需要这些信息，以便在必要时进行技术改造，从而提高其产品的生态质量，并使其更具竞争力。对于像油漆和清漆这样的湿材料，由于其非吸附性和非多孔性，通常在将材料涂覆在惰性基材上之后进行VOC排放研究。然而，在实际室内环境中，这些材料是涂覆在不同性质的基材上的。这项工作的一个目的是首次研究涂覆在混凝土上的乳胶漆的VOC排放。还研究了基材（未涂覆的软木地板、未上漆的桉木地板和上过漆的松木地板）对水性清漆VOC排放的影响。为了进行比较，两种湿材料都使用了聚酯薄膜（一种惰性基材）。
在标准化测试舱的大气中，对材料暴露的前72小时监测主要VOC的特定排放率。空气样品采集在Tenax TA上，并使用配备质量选择性检测和火焰离子化检测的气相色谱在线热脱附进行分析。将双指数模型应用于VOC浓度随时间的变化，以便于结果的解释。
在最后一层材料涂覆23小时后引入测试舱的清漆，主要排放乙二醇醚。只排放了主要VOC，但它们的浓度因基材性质而有显著差异。软木和桉木地板的VOC浓度较高，这表明它们具有更高的孔隙率，因此比上过漆的松木地板（和聚酯薄膜）具有更高的VOC吸附能力。油漆在涂覆后立即引入测试舱。只排放了主要VOC（酯类、邻苯二甲酸盐、乙二醇醚和白节油），但某些化合物，如2-（2-丁氧基乙氧基）乙醇和邻苯二甲酸二乙酯，仅在油漆/聚酯薄膜中被检测到，这表明它们被油漆/混凝土不可逆地吸附。与惰性基材相比，混凝土在湿阶段（油漆涂覆后的最初几小时）的VOC排放率较低，但由于解吸作用，后期（干燥阶段）略高。
对于清漆，未涂覆的基材，如软木和桉木地板，比上过漆的松木地板表现出更高的VOC吸附能力，可能是因为它们具有更高的孔隙率。对于油漆，混凝土排放的VOC总量低于聚酯薄膜，这表明混凝土减少了乳胶漆的全球VOC排放。混凝土被认为具有很强的VOC吸附能力。某些化合物，即2-（2-丁氧基乙氧基）乙醇、邻苯二甲酸二乙酯和TEXANOL（部分），要么被混凝土不可逆地吸附，要么解吸非常缓慢（在未检测到的水平）。之前研究的油漆基材石膏板没有报道过类似的行为。
目前的数据表明，在室内环境中，混凝土可能是一种推荐的油漆基材。由于基材的性质决定了湿材料VOC排放的速率和性质，在报告复合材料的排放时必须明确，以便在室内空气质量方面对产品进行比较和标注。
