Influence of water content in sub-flooring materials using adhesive on chemical compounds emission

Indoor air pollution is caused predominantly by emission of primary pollutants from building materials or finishing materials. Recently, there has been increasing interest in the new secondary pollutants caused by chemical reaction of the primary pollutants. In this study, the pollutants emitted from poly(vinyl chloride) (PVC) flooring material were measured, and 2-ethyl-1-hexanol (2E1H) and volatile organic compounds (VOCs) emitted from composite building materials made of PVC flooring material used as a self-leveling flooring were measured to identify the mechanism of emission of 2E1H. The moisture sorption isotherm was measured with a Magnetic Suspension Balance to examine the moisture content of the self-leveling flooring material and its effect on emission of 2E1H. 2E1H was emitted from the PVC flooring material through hydrolysis or oxidation of di-2-ethylhexyl phthalate (DEHP). The composite building material including the self-leveling flooring material emitted more 2E1H through hydrolysis over time. It was determined that liquid prevails in the self-leveling flooring material when the water content is higher than 4% and vapor prevails when the water content is lower than 4%. The prevailing liquid in the flooring material contributes to the increased emission of 2E1H and the prevailing vapor in the material did not cause increase in emission of 2E1H. It is considered that control of water in the self-leveling flooring material or concrete slab is very important in order to inhibit emission of 2E1H through hydrolysis of DEHP on the floor.     

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.     

Resuspension of Dust Particles in a Chamber and Associated Environmental Factors

Experiments investigating particle resuspension from human activities were conducted in a full-scale experimental chamber. The experiments tested three types of flooring (vinyl tiles, new and old level-loop carpets) and two ventilation configurations (ceiling and side wall supply systems). The floorings were seeded with 0.1–10 μ m test particles. The airborne particle concentration was measured by an array of optical particle counters (OPCs) in the chamber. Resuspension rates were estimated in size ranges of 0.8–1, 1.0–2.0, 2.0–5.0, and 5.0–10 μm ranging from 10^?5–10^?2 hr^?1, with higher resuspension rates associated with larger particles. Resuspension via walking activity varied from experiment to experiment. “Heavy and fast” walking was associated with higher resuspension rates than less active walking, most likely due to a combination of increased pace, increased air swirl velocity, and electrostatic field effects established by the walking. The type of floorings also influenced the particle resuspension. Given the same size and mass distribution of test particles per unit floor area, resuspension rates for the seeded new level-loop carpet were significantly higher than those for the vinyl tile flooring for larger particles (1.0–10 μ m) under the ceiling air supply system.     

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.     

Cold weather installation of wood flooring by adhesive bonding and its impact on indoor air quality

This study discusses the effect of installation of wood flooring by adhesive bonding under cold weather conditions on indoor air quality (IAQ) and analyzes an onsite strategy that can ensure the adhesion strength of the wood flooring and improve IAQ. To examine the temperature effects of adhesive bonding on volatile organic compound (VOC) emissions from wood flooring, the emission rates from flooring composites were compared with those from adhesive and plywood flooring as individual materials under temperature variations in a small-scale chamber. In addition, the effect of strategies, including room heating to enhance adhesion performance, and the ventilation on material emissions and indoor concentrations, were examined in onsite apartment units equipped with a radiant floor heating system. The results of the small-scale chamber test showed that VOC emissions increased notably when the temperature was elevated, particularly in the adhesive-bonded plywood flooring compared to plywood flooring alone. The results of the onsite field test showed that the flooring bonded onto the radiant floor heating system, which supplied direct heat to the flooring, caused emission of a large amount of VOCs due to the combined effects of the bonding installation and temperature-dependent characteristics. Overall, the results indicate that heating the room in conjunction with ventilation is an effective strategy to ensure adhesion strength and to improve IAQ under cold weather adhesive bonding conditions when the material temperatures can be properly maintained.     

以废PVC农膜为原料生产PVC地砖基片

研究了采用活性重质碳酸钙（ＣａＣＯ３）填充的废聚氯乙烯农膜（ＷＰＶＣ）为原料，生产ＰＶＣ地砖基片，并研究了该原料对体系加工性能和物理机械性能的影响。介绍了ＰＶＣ地砖的工艺技术、ＰＶＣ地砖基片配方的选择及最佳工艺条件的确定。结果表明：热压贴合成型ＰＶＣ高填充地砖的加工技术可行，利用废ＰＶＣ农膜生产ＰＶＣ地砖基片，降低了产品成本，具有可推广性。     

The sorption of sulphur dioxide by indoor surfaces. IV. Flooring materials

The sorption of sulphur dioxide by a number of carpet and solid flooring material samples has been investigated at a concentration of 50 to 60 μg/m³ using ³⁵S-labelled sulphur dioxide. The amount of sulphur dioxide sorbed by the samples varied little with their chemical composition and was of such a magnitude as to suggest a low affinity of the surfaces for sulphur dioxide. The sorption of sulphur dioxide by artificial fibre carpet pile was shown to be significantly reduced by the application of dyes.     

Effect of Soil Type and Momentum on Unpaved Road Particulate Matter Emissions from Wheeled and Tracked Vehicles

Excluding windblown dust, unpaved road dust PM ₁₀ emissions in the US EPA's 2002 National Emission Inventory account for more than half of all PM ₁₀ emissions in the arid states of the western U.S. (i.e., CA, AZ, NV, NM, and TX). Despite the large size of the source, substantial uncertainty is associated with both the vehicle activity (i.e., number of kilometers traveled at a particular speed) and the emission factors (i.e., grams of PM ₁₀ per kilometer traveled). In this study, emission factors were measured using the flux tower method for both tracked and wheeled military vehicles at three military bases in the Western U.S. Test vehicle weights ranged from 2400 kg to 60,000 kg. Results from both previously published and unpublished field studies are combined to link emission factors to three related variables: soil type, vehicle momentum, and tred type (i.e., tire or track). Current emission factor models in US EPA's AP-42 Emission Factor Compendium do not factor both speed and weight into unpaved road emission factor calculations. Tracked vehicle emission factors from Ft. Carson, CO, and Ft. Bliss, TX were related to vehicle momentum (speed ? mass) with ratios ranging from 0.004–0.006 (g-PM vkt^{? 1})/(kg m s^{? 1}). For similar vehicle momentum, wheeled vehicles emitted approximately 2 to 4 times more PM ₁₀ than tracked vehicles. At Yakima, WA, tracked vehicle PM ₁₀ emission factors were substantially higher (0.38 (g-PM vkt^{? 1})/(kg m s^{? 1})) due to the unique volcanic ash soil characteristics (48% silt). Results from PI-SWERL, a portable wind tunnel surrogate, are presented to assess its utility to predict unpaved road dust emissions without the deployment of flux tower systems. PI-SWERL showed only a factor of 6 variation between sites in comparison with the 60-fold variation as measured by the flux towers.     

Flexible Poly(Vinyl Chloride)-Zeolite Composites for Dye Adsorption from Aqueous Solutions

Abstract

Flexible poly(vinyl chloride) (PVC) composites having natural zeolite clinoptillolite were prepared by plastisol-plastigel technology. Adsoption of methylene blue on each raw material and on composites was studied both from an equilibrium and a rate approach. It was observed that the adsorption capacity of zeolite decreased when it was embedded in composites. The equilibrium uptake of methylene blue increased with an increasing zeolite fraction in composites. Methylene blue was adsorbed from a 0.02 g·cm^?3 aqueous solution slowly, but was nearly adsorbed completely with a composite having a 0.3 volume fraction of zeolite. The effective diffusion coefficient of methylene blue in composites was of the order of 10^?13 m²·s^?1 and decreased with increasing filler fraction.     

Dynamics of ion beam modification of polymer films

Thin polymer films were irradiated in a high vacuum environment with energetic (～2 MeV) ions. The emitted molecular species were studied with a quadrupole mass spectrometer during bombardment. The emitted species are predominantly small molecules. The efficiency of emission depends strongly upon the electronic energy loss of the incident ions in the film and, hence, upon the velocity and atomic number of the incident ion. The emission efficiency of all species decreases with increasing damage in the film. By pulsing the ion beam, the time dependence of irradiation induced emission of molecular species from the films has been studied. Emission delays of hundreds of milliseconds are observed in some cases. These delays are found to depend upon the emitted species as well as the host film and seem to be associated with diffusion of the species in the films.     

Adhesives formulated with chemically modified okara and phenol–resorcinol–formaldehyde for bonding fancy veneer onto high-density fiberboard

With an abrupt increase of petrochemical prices and the critical environmental issue related to the volatile organic compounds emitted from the adhesive resins, the development of environmentally friendly new adhesive systems is common issue. In our study, the okara, which is a residue from the production of tofu, was introduced to develop competitive bio-based adhesives for the production of fancy-veneered floor boards. Okara (AC and AK) was hydrolyzed with 1% sulfuric acid solution and 1% sodium hydroxide solution. Phenol–resorcinol–formaldehyde (PRF) prepolymer was prepared as a crosslinker of AC and AK. Adhesive resins were formulated with AC, AK and PRF prepolymer. The adhesive resins were used to fabricate floor boards composed of oak veneers onto high-density fiberboard. The experimental variables were three weight ratio of AC/AK to PRF (45/45/10, 40/40/20 and 35/35/30), three assembly time (0, 10 and 20 min), and two press time (90 and 120 s), respectively. The fancy-veneered high-density fiberboards were prepared and subject to testing of the dry tensile strength, glueline failure by wetting and formaldehyde emission. Dry tensile strengths of the boards exceeded the requirement of KS standard. The formaldehyde emissions were satisfied with the limitation specified in KS standard. Based on these results, okara has a potential to be used as a renewable raw material of environmentally friendly adhesive resin systems for production of floor boards, but further researches, such as biological hydrolysis of okara and various formulations of PRF prepolymer, are required to improve the adhesive strength and to reduce formaldehyde emission of okara-based adhesive resins.     

Migration of phthalate and non‐phthalate plasticizers out of plasticized PVC films into air

The aim of the present work is to provide information about the migration of phthalate and non‐phthalate plasticizers generally used in flexible polyvinyl chloride (PVC) applications. Plastisols (pastes) were prepared by mixing PVC, plasticizer, and thermal stabilizer. The plasticized PVC (p‐PVC) films are obtained by gelation at 160°C for 15 min. The p‐PVC films were heat treated at 50, 85, 100, 130, and 160°C up to 420 min to follow the mass loss to find out diffusivity of plasticizer out of films into air and to determine related activation energies. The films having di‐octyl terephthalate (DOTP) and di‐isononyl 1,2‐cyclohexanedicarboxylic acid (DINCH) exhibited the lowest mass loss in general, among the phthalate and non‐phthalate plasticizer having p‐PVC films, respectively, as confirmed by FTIR investigation. The same tendency was observed for diffusion coefficients and for the activation energies of migration. The diffusion coefficients were found to be around 3.5 × 10^?18–2.1 × 10^?17 m²/sec for the studied plasticizers in PVC at 50°C and around 4.0 × 10^?15–9.9 × 10^?14 m²/sec at 160°C. The activation energies for 85–160°C interval were determined to be between 70 and 153 kJ/mol (0.72–1.58 eV) for the plasticizers used herein those could be treated as a homologous series as deduced from the related compensation factors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PS型胶粘剂的制备

主要介绍了PS型胶粘剂的制备方法，讨论了胶粘剂中各组分对粘接强度及其性能的影响和作用。通过共混改性和溶剂优选，制备了耐水性优良、耐油性好的PS型胶粘剂，该胶在性能上优于903建筑多用胶，可用于瓷砖、地板、马赛克、大理石、水泥制品、陶瓷、塑料等多种材料的自粘互粘．     

Numerical and experimental study of ion exchange in porcelain tiles

Recently ion exchange, also known as chemical tempering, has been applied to strengthening of porcelain tiles based on the substitution of ions present in the material by larger ones. This paper investigates the chemical tempering in industrial porcelain tiles by the variation of process parameters such as temperature, immersion time, and chemical composition of the porcelain tile. Furthermore, a numerical simulation of the ionic diffusion process was applied. Using a design of experiments approach, the results show that the temperature and the chemical composition primarily affected the flexural strength of the tile. The largest increment obtained was 37% resulting in a porcelain tile with flexural strength of 73 MPa after chemical tempering. Through numerical simulation, it was possible to estimate a diffusion coefficient of potassium ions equal to 1.25 × 10⁻¹⁴ m²·s⁻¹ into the porcelain tile microstructure. This value is about 10 times higher than the diffusion coefficient in glasses.     

高填充PVC地砖的研制

主要研究了高速配混料和成型工艺对高填充地砖基片性能的影响,并相应地提出了配方和工艺控制参数.对用活化填料改善填充体系性能的机理作了初步探讨.实验结果表明,高填充PVC地砖的加工技术可行,经济合理,具有很好的推广价值.所用的活化填料对体系的成型加工性能和材料的机械性能都有所改善.     

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...     

Dialkyldithiophosphate substituted on poly(vinylchloride): Synthesis and performance

Preparation of sodium salt of di(2-ethylhexyl)dithiophosphoric acid (DTPANa) by reaction of the corresponding DTPA with sodium hydride has been described. Nucleophilic substitution of chlorine on poly(vinylchloride) (PVC) by a di(2-ethylhexyl)dithiophosphate group resulting in modified polymer (MP) was characterized by the second order rate constant equal to 6.6 × 10^?5 M^?1 s^?1. Formation of homogeneous stable gelled phases composed of MP and DTPA, as well as MP, PVC, and DTPA, was demonstrated. The gelled material is capable of selective separation of metal ions under the conditions of extraction chromatography. © 1993 John Wiley & Sons, Inc.     

Gross mineralization, nitrification and N2O emission under different tillage in the North China Plain

No-tillage cropping can increase soil carbon (C) stocks and aggregation, and subsequently impact the internal nitrogen (N) cycle and gas loss. The ¹⁵N pool dilution method was used to study gross N transformations, and relative proportions of nitrous oxide (N₂O) emissions derived from denitrification versus nitrification-related processes under long-term tillage systems (no-tillage, rotary tillage and conventional tillage) in the North China Plain. In-field incubation experiments were repeated in successive growing seasons during April?CNovember in 2007. Gross mineralization rates for rotary and mouldboard plough tillage (3.6?±?0.3?C10.6?±?1.5?mg?N?kg^?1?days^?1) were significantly higher than for no-tillage (1.7?±?0.8?C6.8?±?1.1?mg?N?kg^?1?days^?1). Gross mineralization was positively correlated with soil moisture and temperature, as well as with microbial biomass N and C. However, there was no consistent tillage effect on gross nitrification, and gross nitrification was positively correlated with soil moisture, but not with gross mineralization and microbial biomass. N₂O emissions were higher in no-tillage (NT) than for conventional tillage (CT) during May?CAugust. The ¹⁵N labelling indicated that 26?C92?% of the N₂O was directly derived from the soil ammonium (NH₄ ⁺) pool. Emission rates of N₂O from both nitrification and denitrification were positively correlated with NH₄ ⁺ supply as expressed by gross mineralization, but not correlated with supply of nitrate as expressed by gross nitrification. The fraction of nitrified N emitted as N₂O was positively correlated with changes in soil moisture and varied within 0.01?C2.51???. Our results showed that the tillage management impact on gross N transformation was not consistent with N₂O emission, and more detailed information on the controls over N₂O formation needs to be sought.     

Infrared study of combined effect of γ-radiation and elevated temperature on poly(vinyl chloride)

Infrared absorption spectroscopy has been used to investigate the combined effect of γ-radiation and heat on poly(vinyl chloride) (PVC). The recorded spectra showed that exposure of PVC samples to gamma doses from 0.5 to 15 Mrad results in remarkable changes in the absorbances of their absorption bands. Also, the exposure to doses from 3 to 15 Mrad results in an appearance of a C?O band at 1720 cm^?1 and O? H band at 3450 cm^?1. The nature of the formation of these bands was discussed in terms of peroxide-mediated oxidative degradation mechanism. Moreover, it was found that heat treatment of PVC samples over the temperature range 25–180°C causes no noticeable changes in their spectra apart from slight changes in the absorbances of the bands. On other hand, it was found that heat treatment of the irradiated samples causes considerable increase in the intensity of the C?O band. In addition to the well-defined and sharp band appearing at 1720 cm^?1, the spectra of the samples irradiated with 10 and 15 Mrad exhibited two bands at 1070 and 1120 cm^?1. The obtained data led also to the conclusion that the C? Cl bands cannot be used as a measure of crystallinity of PVC.     

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。