| The large-scale use of architectural paints in the decoration process is one of the major causes of indoor VOCs pollution.Among them,the adverse health effects of formaldehyde on the human body have drawn wide attention.At present,there is a lack of research on the relationship between temperature and the key emission parameters(initial emitable concentration C0,diffusion coefficient Dm and partition coefficient K)of VOCs emission from architectural coatings.In addition,few studies have been conducted on the impact of pressure on the emission of VOCs in architectural coatings,and the combined effect of two or more environmental factors on emission and human exposure is seldom touched upon.Therefore,in view of the above research deficiencies,this paper mainly has the following research contributions:Firstly,the emission of formaldehyde in building paint between 5 ? and 35 ? was studied through environmental chamber experiment,and the value of key emission parameters was calculated.Based on the experimental data,former models were modified to present the relationship between temperature and the key emission parameters suitable for solvent-borne coatings.Different variation law of the key emission parameters was found when the temperature changes around 25 ? or above.From the perspective of molecular kinetic energy and coating film formation,the mechanism of temperature affecting the formaldehyde emission of solvent-borne coatings was explained.Secondly,for the first time,the influence of pressure on the emission of formaldehyde in architectural paints was investigated experimentally.The key emission parameters of formaldehyde in solvent-borne paints were measured under four pressure which ranges of 70.5-101.5 kPa.Based on the relationship between temperature and the key emission parameters,the values of pressure and key emission parameters were fitted and the corresponding relationships were obtained.With the help of the explanation of the molecular dynamics mechanism of gas diffusion in the related research,the mechanism of the influence of pressure on the emission of formaldehyde in solvent-borne coatings was analyzed.Finally,based on the study of the correlation between the key emission parameters of formaldehyde in solvent-based coatings and temperature and pressure,respectively,the combined effect of temperature and pressure on the key emission parameters was investigated.This relationship can be used to predict the emission of formaldehyde in architectural paints and the resulting exposure to pollutants under other temperature and pressure conditions.This would provide theoretical basis to the improvement and control of pollutant content limitations in architectural coatings. |
PDF Full Text Request