溶剂型木器涂料中挥发性有机化合物释放规律

Study on VOC Emission Rule in Solventborne Wood Coatings

小型气候箱模拟典型室内空气条件,不同时间用椰子壳活性炭吸附管收集一定体积硝基、多组分聚氨酯清漆涂膜释放出的VOC与空气的混合气体,气相色谱法测定二硫化碳提取液中VOC组分浓度的实验方法,研究了溶剂型木器涂料成膜后VOC的气相浓度由迅速衰减、过渡和缓慢衰减三个过程构成并受液-气界面压力差和解吸的控制,基于数据分析建立定量描述涂料涂装后气相浓度与涂膜中VOC组分量、空气交换率、实验仓容积相互关系的数学模型。气相浓度的衰减率Rr可表征VOC释放特性,温度、湿度、空气交换率条件对气相浓度衰减率影响研究表明其与温度、组分的色谱保留时间存在函数关系。

The small- scale environmental chamber was used to simulate the typical indoor conditions. The adsorption tube filled with coconut -shell absorbent charcoal was also used to collect the certain volume of the gas mixture of air and the VOC emitted from the film of nitrocellulose coatings and polyurethane coatings when the film was dried at different time. Extracted by CS2, the components were analyzed by GC. The gas - phase VOC concentration at different time, when the films of solvent - based wood coatings was used indoor, had been discussed. The results showed that gas -phase VOC concentration decay process with the time was in three steps - fast decay, transition and slow decay and controled by pressure difference in the liquid - air interface and desoption. Based on the analysis of the experiment data, the corresponding mathematical model was established to quantitatively describe the correlations of gas - phase concentration of VOC and VOC content in paints, air exchange rate and volume of the chamber. The decaying factor R, indicated the influence of VOC emission feature, temperature, humidity and air exchange rate on gas - phase concentration decay, which is related to temperature and retention time in GC.