Measurement of 2-ethyl-1-hexanol emitted from flooring materials and adhesives

It has been reported that 2-ethyl-1-hexanol (2E1H) was emitted through hydrolysis between di-2-ethylhexyl phthalate used as plasticizer in flooring material and moisture generated from a strongly alkaline material such as concrete slab. The purpose of this study was to clarify the relationship between diffusion of 2E1H in flooring material and 2E1H emission rate from floor surface. In this study, we measured 2E1H emitted from floor paper, poly(vinyl chloride) (PVC) tile, cushion floor and carpet for 200,?days and effective diffusion coefficients for 2E1H in various flooring materials were measured. Effective diffusion coefficients of 2E1H for cushion floor and PVC tile were 115?×?10^?9 and 7.8?×?10^?9 m²/s, respectively. Emission rate of 2E1H emitted from flooring material significantly depends on the kind and shape of flooring materials and was influenced by the effective diffusion coefficient for 2E1H of flooring material. Emission rates of 2E1H from floor surface varied with the amount of 2E1H and resin present in the adhesive. When carpet was attached to the flooring material with high water content using adhesive, emission of 2E1H significantly increased. The results show that primary and secondary emissions of 2E1H from the adhesive influence the emission rate of 2E1H for flooring material.     

Control of emission rates of chemical compounds emitted by controlling their mass transfer coefficients on the surface of the tested building material

The air change rate in the chamber, the loading factor of the materials, and the mass transfer coefficient are very important factors in the measurement of chemical compounds, because they have a decisive effect on emission rates of chemical compounds emitted from materials. Small 20-liter chambers, such as the advanced pollution and air quality chamber, are generally used in Korea and Japan for measuring the amount of released chemicals. In this study, chemical compounds released from building materials and adhesives were measured using a chamber proposed by the authors to control the mass transfer coefficient on the surface of the tested building material and we examined the distribution of chemical compounds concentrations in the chamber by means of computational fluid dynamics to confirm test reliability. The chamber was controlled and maintained at 28?°C, a relative humidity of 50%, a mass transfer coefficient of 14?m/h with an air change rate of 0.50?h^?1, and formaldehyde and total volatile organic compounds were emitted from the flooring material and adhesive. As the mass transfer coefficient on the surface of the tested building material increased, the emission rates of chemical compounds measured using the proposed chamber increased. The mass transfer coefficient on the surface of the tested building material significantly influenced the emission rates of the chemical compounds released from the building material and adhesive.     

Drying and Hydration of Cement Based Self-Leveling Flooring Compounds

Water in building materials not only influences important physical properties and chemical processes but is also related to the well-being of the occupants of a building. The drying of cementitious materials is complex, involving several different drying processes. The conditions for each drying process change as the material changes its properties as it goes from a particle suspension in the fresh state to a fine porous material in the hardened state. The present article describes and quantifies the drying processes of cement-based self-leveling flooring compounds (SLCs) and relates them to the extent of reaction, which here is quantified by isothermal calorimetry. The relative importance of the different drying processes is discussed and a model for the drying of the SLCs is proposed.     

Drying and Hydration of Cement Based Self-Leveling Flooring Compounds

Water in building materials not only influences important physical properties and chemical processes but is also related to the well-being of the occupants of a building. The drying of cementitious materials is complex, involving several different drying processes. The conditions for each drying process change as the material changes its properties as it goes from a particle suspension in the fresh state to a fine porous material in the hardened state. The present article describes and quantifies the drying processes of cement-based self-leveling flooring compounds (SLCs) and relates them to the extent of reaction, which here is quantified by isothermal calorimetry. The relative importance of the different drying processes is discussed and a model for the drying of the SLCs is proposed.     

含氯废弃物燃烧过程中HCl排放特性

引　言生活垃圾中含有的有机氯主要以PVC塑料的形式存在 ,我国塑料制品中PVC占 30 %以上 ;无机氯通常以NaCl的形式存在于厨余中 ,单独焚烧厨余物 (主要含无机氯化物 )会导致大部分氯化物转化为HCl[1] .郭小汾等[2 ] 研究了PVC的燃烧特性和HCl的析出机理 ,认为PVC的燃烧过程分为     

脱硫石膏基无砂自流平砂浆的制备与性能研究

采用脱硫建筑石膏、P·O 42.5水泥、粉煤灰、石灰石超细粉以及外加剂为原料制备脱硫石膏基无砂自流平砂浆。采用正交试验确定石膏基胶凝材料的最优配合比,研究缓凝剂和纤维素醚对石膏基无砂自流平砂浆的性能影响,并利用XRD和SEM分别分析胶凝体系的水化产物和微观形貌,通过分析结果进一步研究外加剂的作用机理。结果表明:当脱硫石膏、水泥、粉煤灰和石灰石超细粉的质量比为16:1:2:1时,石膏基胶凝材料的强度最优;缓凝剂明显延长砂浆的凝结时间,但会导致砂浆产生泌水现象;纤维素醚可以提高砂浆的保水性,纤维素醚的引气作用造成砂浆强度下降。脱硫石膏基无砂自流平砂浆的性能指标满足《石膏基自流平砂浆》(JC/T 1023—2007)的要求。     

Influence of VOC and formaldehyde emission from tile adhesives on their indoor concentrations in buildings

Volatile organic compounds (VOC) and formaldehyde emitted from building materials are considered to be one of the main causes of indoor air pollution in buildings. To reduce indoor pollutant concentrations, new installation methods for wall papers and flooring materials have been widely introduced to the construction field, including a nonadhesive floating method. However, adhesives are still widely used to install wall tiles or floor tiles on areas such as kitchens, bathrooms, and showers. The objective of this study was to investigate the influence of tile adhesive emissions on indoor air quality. The VOC and formaldehyde emission rates from two different types of tile adhesives, a conventional adhesive and a low-VOC emission adhesive, were measured using small emission test chambers. Full scale experiments were also carried out in three identical test rooms in a building. One wall of each room was finished with wallpaper in Test Room 1 and with tiles in Test Rooms 2 and 3. The other walls and ceilings were finished with wall papers in all test rooms. Wall tiles of Test Room 2 were installed with the conventional adhesive, while those of Test Room 3 were installed with the low-VOC emission adhesive. The indoor VOC concentrations in Test Room 2 were significantly higher than those in Test Room 3 due to a significantly higher VOC emission from the conventional tile adhesive. Even though the adhesives were applied under the finishing materials, investigation revealed that the adhesives were the most dominant contributor of indoor VOC concentration.     

PVC地板行业研究现状及发展趋势

概述了国内外PVC地板行业的生产及应用现状,比较了几种地板材料的优缺点,介绍了PVC地板生产技术的研究进展情况,分析了国内PVC地板行业的发展趋势。     

碳足迹评价方法学在PVC产品中的应用

河北盛华化工有限公司率先在氯碱行业引入PAS2050碳足迹评价方法学,对产品或服务在生命周期内的碳排放进行评价,为碳减排提供重要依据.详细计算PVC产品中碳足迹(排放CO2当量),结果表明:生产1 t PVC排放CO2当量为1 765.317 kg,其中原材料消耗占排放CO2当量总量的72.4%,能源消耗占排放CO2当...     

A Method to Measure Emissions from Dryers with Diffuse Leakages, Using Evaporated Water as a Tracer

This paper describes a novel method to measure emission from dryers. The method resolves the known difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapor to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted VOCs and to determine the moisture content of the drying medium.     

Reconstruction of an arson hospital fire

An arson fire in a Swedish psychiatric detention clinic led to the death of two patients and injuries to many more. Rescue personnel were quick to go into the building on fire but had difficulties finding their way due to a very heavy smoke. The reconstruction made, indicates that a too easily ignitable mattress provided heat and radiation enough to ignite a PVC flooring material that then became the main source for fire and smoke. Analysis of soot from the fire site and measurements during the reconstruction show that the fire smoke contained large amounts of irritants that might have had an impact on the tragic outcome. In fact, comparing the toxicity of smoke gases produced during the reconstruction, based on different ‘toxicity indicators’, suggests that irritants in the fire smoke were as dangerous as or even more dangerous than the common asphyxiate type of gases present, CO and HCN. Another suggestion from the reported work is that the importance of flooring material for enclosure fire development might be overlooked. The reconstruction clearly demonstrates that the tragic fire would not have happened if the requirements for the flooring material had been the same as for the walls and ceiling materials. Copyright © 2006 John Wiley & Sons, Ltd.     

Some Considerations in Modeling of Moisture Transport in Heating of Hygroscopic Materials

Hygroscopic materials are those in which the equilibrium pressure of water vapor changes with moisture content and temperature, such as food, soil or wood, etc. Heat and moisture transports are coupled in heating of hygroscopic materials. One of the major links between temperature and moisture changes is water evaporation. There have been different formulations on modeling of evaporation in the past. A typical approach (Model 1 in this article) is to equate the evaporation rate to the rate of local moisture loss. The first part of this paper illustrates that such an approach is physically incorrect based on fundamental conservation relationships. A conservation-based coupled heat and moisture transfer model (Model 2) is presented here based on previous multiphase transport models. It shows that total evaporation rate over the entire material is included in Model 1 while the local evaporation rate is not. The situations when Model 1 may or may not generate large errors are discussed. The second part of this article completes the modeling of evaporation using Model 2. Two types of formulations are given depending on the phase equilibrium of moisture in the hygroscopic materials. When phase equilibrium between water and vapor is assumed for any location at any time, vapor pressure is provided as known variables. In a nonequilibrium approach, evaporation rate needs to be provided. The latter poses numerical difficulties near the material surface, which arises from the possibility that equilibrium state may have a large change near the surface. Further discussions were made on the physical and numerical considerations in using both approaches.     

High temperature catalytic combustion of methane and propane over hexaaluminate catalysts: NOx emission characteristics

Several hexaaluminate-related materials were prepared via hydrolysis of alkoxide and powder mixing method for high temperature combustion of CH₄ and C₃H₈, in order to investigate the effect of the concentration of the fuels, O₂ and H₂O on NO_x emission and combustion characteristics. Among the hexaaluminate catalysts, Sr_0.8La_0.2MnAl₁₁O₁₉₋ prepared by the alkoxide method exhibited the highest activity for methane combustion and low NO_x emission capability. NO_x emission at 1500 °C was increased linearly with O₂ concentration, whereas water vapor addition decreased NO_x emission in CH₄ combustion over the Sr_0.8La_0.2MnAl₁₁O₁₉₋ catalyst. In the catalytic combustion of C₃H₈ over the Sr_0.8La_0.2MnAl₁₁O₁₉₋ catalyst, the amount of NO_x emitted was raised in the temperature range between 1000 and 1500 °C when the C₃H₈ concentration increased from 1 to 2 vol.%. It was found that NO_x emission in this temperature range was reduced effectively by adding water vapor.     

新型防静电聚氯乙烯塑料地板贴面材料的研制

叙述了新型防静电聚氯乙烯塑料地板贴面材料的研制工艺、防静电结构的设计、防静电性能，讨论了其增塑体系与稳定体系，试验表明，该材料具有优良的防静电性能。     

A Method to Measure Emissions from Dryers with Diffuse Leakages,Using Evaporated Water as a Tracer

Abstract

This paper describes a novel method to measure emission from dryers. The method resolves the known difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapor to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted VOCs and to determine the moisture content of the drying medium.     

Moisture absorption in foam‐cored composite sandwich structures

The hygroscopic behavior of sandwich structures composed of E‐glass/polyester face sheets bonded to a PVC foam core exposed to 95% relative humidity and immersed in sea‐water is examined herein. Moisture uptake was monitored for 11 months yielding absorption curves for samples of polyester resin, laminated composites, PVC foam core, and a sandwich structure. The coefficients of diffusion and moisture saturation values extracted from the curves are significantly greater for the water immersed condition than for the exposed to elevated moisture one, and point to the foam core as the most absorbing material in the sandwich structure. The measured absorption curves are compared to a diffusion model which employs the calculated coefficient of diffusion, showing good agreement. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

TiO2光催化氧化气相甲醛暾研究进展

室内多种建筑材料释放出的甲醛，对人类的生存危害极大。因此，用TiO2光催化剂降解气相甲醛成为一个研究热点。文章回顾了近年来用TiO2光催化剂降解气相甲醛取得的成果。     

Hydrogen chloride evolution from the heating of poly(vinyl chloride) compounds

The dehydrochlorination and the thermal decomposition of five PVC materials was studied using two techniques: a batch analytical method, combining ion chromatography and atomic absorption and continuous thermogravimetry. The temperatures studied ranged from 60°C to 120°C, over a period of almost one year (50 weeks). It was found that a very large proportion of the soluble chloride emitted early on by the PVC materials into the liquid phase is not hydrogen chloride. None of the five materials tested emitted significant amounts of HCl at temperatures lower than 105°C. The emissions at 90°C after 50 weeks ranged from <0.01 Φg/g to 23.62 Φg/g. Furthermore, one of the materials tested emitted virtually no HCl, even at 105°C, as the amount of HCl measured was almost indistinguishable from the normal background of the analytical instruments (37.30 Φg/g after 50 weeks). Numerical calculations of kinetic reaction rates and extrapolation of the results to use temperatures (40°C) indicate that properly stabilized PVC compounds will be unlikely to lose 1% of the mass of PVC as HCl until 2 billion years have passed. This number has no physical meaning as such and may be incorrect by a vast margin, but it clearly indicates that a 1% loss of HCl is unlikely to occur during the useful lifetime of a commercial product into which the PVC material has been fabricated. This is a conservative estimate, which ignores the much higher activation energy for dehydrochlorination at temperatures below the glass transition temperature (ca. 85°C). Copyright © 2005 John Wiley & Sons, Ltd.     

PCDD/PCDF emissions from co-combustion of coal and PVC in a bubbling fluidised bed boiler

This paper reports on the results obtained in the study of the co-combustion of PVC with hard coal from South Africa in a 0,5 MW_th Bubbling Fluidised Bed Boiler. The research has included the study of the effect of combustion temperature, fluidisation velocity and PVC content. The addition of urea to the raw fuel, as a dioxin-preventing compound has also been evaluated. Results have been analysed in terms of combustion efficiency, major pollutants emission (NO_x, CO), and PCDD/Fs formation in the flue gas and in the fly ash. Under the experimental conditions tested, co-combustion of coal and PVC has proved to be feasible from the combustion efficiency and emission of PCDD/Fs points of view, whose levels remained below limits set by existing legislation on persistent organic pollutants. The addition of solid urea to the fuel blend reduces the amount of chlorinated compounds emitted. However, it has a negative impact on nitrogen pollutants formation     

Effect of partial replacement of di(2‐ethyl hexyl)phthalate,by a polymeric plasticizer,on the permeability and leaching properties of poly(vinyl chloride)

Acrylonitrile butadiene rubber (NBR) was used as a polymeric plasticizer in poly(vinyl chloride) (PVC) for the partial replacement of di(2‐ethyl hexyl)phthalate (DEHP). The effect of this partial replacement on DEHP leaching from the PVC was evaluated at 10, 25, and 40°C. The study shows that the incorporation of NBR reduces the rate of DEHP leaching, the reduction being prominent at lower temperatures. Gas permeability of the NBR‐modified samples was also evaluated at the above temperatures using oxygen and carbon dioxide. A reduction in gas permeability is observed in NBR‐modified samples compared to the PVC plasticized with DEHP alone particularly in the case of carbon dioxide. Water vapor transmission rates of the NBR‐modified samples are higher than that of the control sample. The NBR‐modified PVC sample was found to be noncytotoxic in the in vitro cytotoxic evaluation both by direct contact and test on extract methods. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4720–4727, 2006