材料中SVOC散发关键参数的测定方法及影响因素研究

Measurement and influencing factors of key parameters of SVOC emission from materials

半挥发性有机化合物(SVOC)广泛存在于室内和车内材料中,材料中SVOC的源散发特性由材料/空气界面处气相SVOC质量浓度(y0)和材料表面对流传质系数(hm)2个关键参数表征,准确测定y0和hm是研究SVOC散发规律并进行人体健康风险评估的基础。提出了快速测定y0和hm的变通风量(VVR)法,该方法建立了舱内SVOC准稳态质量浓度值(y)与通风量(Q)之间的理论关系式,通过对Q和y进行线性拟合进而获得y0和hm。实验测定了2种典型车内材料中邻苯二甲酸二异辛酯(DEHP)的散发关键参数值,结果表明,VVR法具有较高的精度。研究了温度(T)对散发关键参数的影响,结果显示y0和hm都随着温度的升高而增加,其中y0的增幅尤为显著。推导了y0和T之间的理论关系式,该式表明y0T的对数与T的倒数呈线性关系。

Semi-volatile organic compounds (SVOC) are widely used in indoor and in-vehicle materials, the emission characteristics of SVOC from materials can be featured by two key parameters: the gas phase SVOC concentration adjacent to the material surface (y0), and the convective mass transfer coefficient across the material surface (hm). Accurate measurement of y0 and hm is a basis for exploring SVOC emission law and assessing human health risks. Proposes a varied ventilation rate (VVR) method to determine y0 and hm quickly. Establishes a theoretical relationship between the steady state SVOC concentration (y) and ventilation rate (Q), and then the y0 and hm could be measured by performing linear fitting to the experimental data with the derived correlation. Measures the key parameters of di(2-ethylhexyl) phthalate (DEHP) from two typical in-vehicle materials with experiment, and the results demonstrate the relatively high precision of VVR method. Studies the influence of temperature (T) on the key parameters, and the results show that both y0 and hm increase with the increase of temperature, especially y0 with significant growth rate. In addition, deduces a theoretical correlation between y0 and T, which indicates that the logarithm of y0T is in a linear relationship with the reciprocal of T.