Health & Environmental Research Online (HERO)


Glycols (25265-71-8, 110-98-5, & 24800-44-0)


96 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Tuning the Ionomer Distribution in the Fuel Cell Catalyst Layer with Scaling the Ionomer Aggregate Size in Dispersion

Authors: Doo, G; Lee, JH; Yuk, S; Choi, S; Lee, DH; Lee, DW; Kim, HG; Kwon, SH; Lee, SG; Kim, HT (2018) ACS Applied Materials and Interfaces 10:17835-17841. HERO ID: 4947115

[Less] With the demands for better performance of polymer electrolyte membrane fuel cells, studies on controlling . . . [More] With the demands for better performance of polymer electrolyte membrane fuel cells, studies on controlling the distribution of ionomers have recently gained interest. Here, we present a tunable ionomer distribution in the catalyst layer (CL) with dipropylene glycol (DPG) and water mixtures as the ionomer dispersion medium. Dynamic light scattering and molecular dynamics simulation demonstrate that, by increasing the DPG content in the dispersion, the size of the ionomer aggregates in the dispersion is exponentially reduced because of the higher affinity of DPG for Nafion ionomers. The ionomer distribution of the resulting CLs dictates the dimensional feature of the ionomer dispersion. Although the ionomer distribution becomes more uniform with increasing the DPG content, an optimal power performance is obtained at a DPG content of 50 wt % regardless of feed humidity because of balanced proton and mass transports. As a guide for tuning the ionomer distribution, we suggest that the ionomer aggregates in the dispersion with a size close to that of the Pt/C aggregates form a highly connected ionomer network and maintain a porosity in the catalyst/ionomer aggregate, resulting in high power performance.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Dispersion-Solvent Control of Ionomer Aggregation in a Polymer Electrolyte Membrane Fuel Cell

Authors: Lee, JH; Doo, G; Kwon, SH; Choi, S; Kim, HT; Lee, SG (2018) Scientific Reports 8:10739. HERO ID: 4947111

[Less] In this study, we examined the influence of the dispersion solvent in three dipropylene-glycol/water . . . [More] In this study, we examined the influence of the dispersion solvent in three dipropylene-glycol/water (DPG/water) mixtures, with DPG contents of 0, 50, and 100 wt%, on ionomer morphology and distribution, using dynamic light scattering (DLS) and molecular-dynamics (MD) simulation techniques. The DLS results reveal that Nafion-ionomer aggregation increases with decreasing DPG content of the solvent. Increasing the proportion of water in the solvent also led to a gradual decrease in the radius of gyration (Rg) of the Nafion ionomer due to its strong backbone hydrophobicity. Correspondingly, MD simulations predict Nafion-ionomer solvation energies of -147 ± 9 kcal/mol in water, -216 ± 21 kcal/mol in the DPG/water mixture, and -444 ± 9 kcal/mol in DPG. These results suggest that higher water contents in mixed DPG/water solvents result in increased Nafion-ionomer aggregation and the subsequent deterioration of its uniform dispersion in the solvent. Moreover, radial distribution functions (RDFs) reveal that the (-CF2CF2-) backbones of the Nafion ionomer are primarily enclosed by DPG molecules, whereas the sulfonate groups (SO3-) of its side chains mostly interact with water molecules.

Book/Book Chapter
Book/ Chapter

Propanediols

Authors: Sullivan, CJ; Kuenz, A; Vorlop, KD (2018) In Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co.. HERO ID: 4940399

[Less] 1,2‐Propanediol, [57‐55‐6], propylene glycol, HOCH2CH(CH3)OH, is very similar to ethylene glycol in . . . [More] 1,2‐Propanediol, [57‐55‐6], propylene glycol, HOCH2CH(CH3)OH, is very similar to ethylene glycol in its physical and chemical properties (→ Ethylene Glycol). The first reported description of 1,2‐propanediol was by Wurtz in 1859 1.

Industrial‐scale synthesis of 1,2‐propanediol from propylene oxide (→ Propylene Oxide) and water began in the 1930s. Current production uses this same process, which leads simultaneously to di‐ and tripropylene glycols. The worldwide capacity for 1,2‐propanediol was predicted at 2.56 × 106 t in 2017 2.

1,2‐Propanediol finds use in diverse applications, such as unsaturated polyesters (→ Polyester Resins, Unsaturated) for thermoset composites, food chemistry, food processing equipment, cosmetics, pharmaceuticals, as well as deicers and automotive antifreeze components (→ Antifreezes).

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Analysis of glycols, glycol ethers, and other volatile organic compounds present in household water-based hand pump sprays

Authors: Kawakami, T; Isama, K; Tanaka-Kagawa, T; Jinnno, H (2017) Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental Engineering 52:1204-1210. HERO ID: 4168926

[Less] The aim of this investigation is to clarify the types and concentrations of VOCs present in various . . . [More] The aim of this investigation is to clarify the types and concentrations of VOCs present in various commercial household water-based hand pump spray products used in Japan, and to estimate their average concentrations in indoor air when the spray product is used. We selected glycol and glycol ethers as the main target compounds, as these chemicals were detected at high frequencies and concentrations in a national survey of Japanese indoor air pollution. The extraction of these chemicals using graphite carbon cartridges was examined, with good recoveries and reproducibilities being obtained. Eighteen chemicals were analyzed in 54 commercial products and 8 chemicals were detected. More specifically, dipropylene glycol (DPG) was present in 44 samples (1.1 × 101-1.8 × 104 μg/mL); propylene glycol (PG) was present in 22 samples (1.5 × 101-2.9 × 104 μg/mL); diethylene glycol monoethyl ether (DGMEE) was found in 15 samples (trace amount-1.9 × 103 μg/mL); diethylene glycol (DEG) was present in 9 samples (1.0 × 101-2.4 × 103 μg/mL); 1,3-butandiol (13BG) was found in 5 samples (trace amount-7.4 × 103 μg/mL); 2-ethyl-1-hexanol (2E1H) was detected in 5 samples (3.2 × 10-1-4.4 × 101 μg/mL); diethylene glycol monobutyl ether (DGMBE) was present in 4 samples (2.1 × 101-7.1 × 101 μg/mL); and 3-methoxy-3-methylbutanol (MMB) was found in 2 samples (2.4 × 101-4.7 × 102 μg/mL). In addition, the average concentrations of these chemicals in indoor air were estimated using their maximum concentrations observed in the spray product. The estimated average concentrations of the chemicals in indoor air were determined to range between 1.0 × 10-2 and 1.0 mg/m3, with the exception of 2E1H and DGMBE. Furthermore, the estimated average concentrations of PG, 13BG, and DGMEE in indoor air were comparable to or higher than those reported in a national survey of Japanese indoor air pollution. It therefore appeared that household water-based hand pump sprays may contribute to the presence of these chemicals in indoor air. In contrast, estimated average concentrations of 2E1H in indoor air were low, its concentrations observed in a national survey of Japanese indoor air pollution are likely due to the use of plasticizers and paints.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Forward osmosis using draw solutions manifesting liquid-liquid phase separation

Authors: Darvishmanesh, S; Pethica, BA; Sundaresan, S (2017) Desalination 421:23-31. HERO ID: 4742957

[Less] Desalination via forward osmosis using draw agents whose regeneration is aided via liquid-liquid phase . . . [More] Desalination via forward osmosis using draw agents whose regeneration is aided via liquid-liquid phase separation has gained much attention in recent years. In the present study, mixtures of two different glycol ethers, tripropylene glycol methyl ether and tripropylene glycol n-butyl ether, have been studied as potential draw agents. Water activity, viscosity and diffusion coefficient of draw solutions have been measured at different mixture compositions, concentrations and temperatures. Osmotic pressures of these draw solutions decreases strongly with increasing temperature. Forward osmosis experiments performed with these draw solutions reveal appreciable initial loss of trans-membrane water flux, reverse solute flux and severe concentration polarization.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Topical delivery of anthramycin I. Influence of neat solvents

Authors: Haque, T; Rahman, KM; Thurston, DE; Hadgraft, J; Lane, ME (2017) European Journal of Pharmaceutical Sciences 104:188-195. HERO ID: 4947114

[Less] Anthramycin (ANT) was the first pyrrolobenzodiazepine (PBD) molecule to be isolated, and is a potent . . . [More] Anthramycin (ANT) was the first pyrrolobenzodiazepine (PBD) molecule to be isolated, and is a potent cytotoxic agent. Although the PBD family has been investigated for use in systemic chemotherapy, their application in the management of actinic keratoses (AK) or skin cancer has not been investigated to date. In the present work, anthramycin (ANT) was selected as a model PBD compound, and the skin penetration of the molecule was investigated using conventional Franz diffusion cells. Finite dose permeation studies of ANT were performed using propylene glycol (PG), 1,3-butanediol (BD), dipropylene glycol (DiPG), Transcutol P® (TC), propylene glycol monocaprylate (PGMC), propylene glycol monolaurate (PGML) and isopropyl myristate (IPM). The skin penetration of BD, DiPG, PG and TC was also measured. Penetration of ANT through human skin was evident for TC, PG and PGML with the active appearing to "track" the permeation of the vehicle in the case of TC and PG. Deposition of ANT in skin could be correlated with skin retention of the vehicle in the case of IPM, PGMC and PGML. These preliminary findings confirm the ability of ANT to penetrate human skin and, given the potency of the molecule, suggest that further investigation is justified. Additionally, the findings emphasise the critical importance of understanding the fate of the excipient for the rational design of topical formulations.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Ring opening polymerization of styrene oxide initiated with potassium alkoxides and hydroxyalkoxides activated by 18-crown-6: determination of mechanism and preparation of new polyether-polyols

Authors: Grobelny, Z; Matlengiewicz, M; Jurek-Suliga, J; Golba, S; Skrzeczyna, K; Kwapulinska, D (2017) HERO ID: 4583202

[Less] It was stated that initiation in ring opening polymerization of styrene oxide depends on the kind of . . . [More] It was stated that initiation in ring opening polymerization of styrene oxide depends on the kind of potassium alkoxide activated by 18-crown-6 used. In the presence of potassium methoxide the oxirane ring opening occurs exclusively in the beta-position and not in the beta or alpha position, i.e., contrary to the previous data. A similar result was obtained in the systems initiated with potassium t-butoxide, 2-methylpropoxide and 1-phenylethoxide. Unexpectedly, potassium i-propoxide and 1-methylpropoxide open the oxirane ring in the beta or alpha position. In all polymerizations, deprotonation of methine group in the monomer takes place under the influence of the initiator and in chain transfer reaction to the monomer. It leads to the formation of macromolecules with unsaturated starting group. However, deprotonation of methylene group in the monomer does not occur. Applying of potassium hydroxyalkoxides, i.e., monopotassium salt of dipropylene glycol or tripotassium salt of 2,2,6,6-tetrakis(hydroxymethyl) cyclohexanol it was possible to synthesize PSO-diols and PSO-pentols without unsaturation. Molar masses of polymers (M-n = 1700-4800 Da) are much higher than reported in literature for other anionic systems. Dispersity of polymers is rather low (M-w/M-n = 1.07-1.15) indicating relatively high rate of initiation and cation exchange reaction.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The effect of oxygenated fuel properties on diesel spray combustion and soot formation

Authors: Park, W; Park, S; Reitz, RD; Kurtz, E (2017) HERO ID: 3847436

[Less] Diesel engines have advantages due to their potential for high fuel conversion efficiency. However, . . . [More] Diesel engines have advantages due to their potential for high fuel conversion efficiency. However, it is necessary to reduce pollutant emissions, particularly NOx and soot to meet emission mandates. Many studies have shown that oxygenated fuel additives can effectively reduce soot emissions. In this research, to investigate the effect of oxygenated fuel properties on combustion and soot emission, CFD simulations were carried out using newly developed chemical mechanisms for various oxygenated fuels such as tripropylene glycol methyl ether, methyl decanoate, and dimethyl ether. The results show that the formation of soot precursors decreases with increased oxygen content and decreased number of C-C bonds in the fuel. The fuel molecular structure strongly affects soot formation in addition to fuel-air mixing. Comparisons of fuel blends (oxygenated fuels with n-hexadecane) including methyl decanoate, which have the same fuel oxygen ratio, show that the effects of the ignition delay and lift-off length control soot formation for fuels with similar fuel oxygen ratio and number of C-C bonds. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Worksite Chemical Air Emissions and Worker Exposure during Sanitary Sewer and Stormwater Pipe Rehabilitation Using Cured-in-Place-Pipe (CIPP)

Authors: Sendesi, SMT; Ra, K; Conkling, EN; Boor, BE; Nuruddin, Md; Howarter, JA; Youngblood, JP; Kobos, LM; Shannahan, JH; Jafvert, CT; Whelton, AJ (2017) HERO ID: 4173202

[Less] Chemical emissions were characterized for steam-cured cured-in-place-pipe (CIPP) installations in Indiana . . . [More] Chemical emissions were characterized for steam-cured cured-in-place-pipe (CIPP) installations in Indiana (sanitary sewer) and California (stormwater). One pipe in California involved a low-volatile organic compound (VOC) non-styrene resin, while all other CIPP sites used styrene resins. In Indiana, the uncured resin contained styrene, benzaldehyde, butylated hydroxytoluene (BHT), and unidentified compounds. Materials emitted from the CIPP work sites were condensed and characterized. An emitted chemical plume in Indiana was a complex multiphase mixture of organic vapor, water vapor, particulate (condensable vapor and partially cured resin), and liquid droplets (water and organics). The condensed material contained styrene, acetone, and unidentified compounds. In California, both styrene and low-VOC resin condensates contained styrene, benzaldehyde, benzoic acid, BHT, dibutyl phthalate, and 1-tetradecanol. Phenol was detected only in the styrene resin condensate. Acetophenone, 4-tert-butylcyclohexanol, 4-tert-butylcyclohexanone, and tripropylene glycol diacrylate were detected only in the low-VOC condensate. Styrene in the low-VOC condensate was likely due to contamination of contractor equipment. Some, but not all, condensate compounds were detected in uncured resins. Two of four California styrene resin condensates were cytotoxic to mouse alveolar type II epithelial cells and macrophages. Real-time photoionization detector monitoring showed emissions varied significantly and were a function of location, wind direction, and worksite activity.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Preliminary study on the biodegradation of adipate/phthalate polyester polyurethanes of commercial-type by Alicycliphilus sp BQ8

Authors: Fernando Perez-Lara, L; Vargas-Suarez, M; Noe Lopez-Castillo, N; Javier Cruz-Gomez, M; Loza-Tavera, H (2016) HERO ID: 4738993

[Less] Accumulation of polyurethane (PU) waste has increased considerably due to its extensive use. Even though . . . [More] Accumulation of polyurethane (PU) waste has increased considerably due to its extensive use. Even though many efforts are being carried out to develop more biodegradable PU, the use of these new materials is far from being commercially available. Here, we analyzed the susceptibility of solid polyester polyurethanes (PS-PU) of commercial-type, to biodegradation by Alicycliphilus sp. BQ8, a polyurethanolytic bacterial strain. Four polyester polyols were synthesized from dipropylene glycol (DPG) or diethylene glycol (DEG), and adipic acid (ADA) or phthalic anhydride (PHA), and were combined with either 4,4- and 4,2-methylene diphenyldiisocyanate (MDI) or 2,4- and 2,6-toluene diisocyanate (TDI). Synthesized polyols and PUs were characterized. PU biodegradation was assessed by the capacity of the polymers to support bacterial growth, and by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) spectroscopy, and gas chromatography/mass spectrometry (GC-MS) analyses. Although all the synthesized PUs supported BQ8 growth, SEM analysis showed that PHA-based PU foams were the most affected by bacterial growth. FTIR spectroscopy and GC-MS analyses of bacterial treated PS-PUs showed that they were attacked at ester and urethane groups, suggesting that esterase and amidase activities are involved. Extra-cellular and membrane bound esterase activities were detected during the five days of analysis. Our results suggest that solid PHA-based PUs might be more susceptible than ADA-based PUs to microbial biodegradation in the environment. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42992.