2-Butoxyethanol system

This paper considers systems of lesser dimensionality than the previous study, namely, systems of two compounds, which (ignoring the vapor) can form only one or two phases. Specifically, excess enthalpies and phase compositions have been measured (at ambient pressure) by isoperibol calorimetry for n-butanol/water at 30.0 and 55.0 °C and for n-butoxyethanol/water at 55.0 and 65.0 °C. (Butanol, or C4E0, is C HgOH butoxyethanol, or C4E1, is C HgCX OH.) The miscibility... 

Although heat capacities have been reported for the butoxyethanol/ water system, excess enthalpies that could be compared directly with our results apparently have not been measured (12). 

Isoperibolic calorimetry measurements on the n-butanol/water and n-butoxyethanol/water systems have demonstrated the accuracy and convenience of this technique for measuring consolute phase compositions in amphiphile/water systems. Additional advantages of calorimetry over conventional phase diagram methods are that (1) calorimetry yields other useful thermodynamic parameters, such as excess enthalpies (2) calorimetry can be used for dark and opaque samples and (3) calorimetry does not depend on the bulk separation of conjugate fluids. Together, the present study and studies in the literature encompass all of the classes of compounds of the amphiphile/CO ydrocarbon/water systems that are encountered in... 

The specific rates of hydrolysis of five organic halides in three water-based liquid mixtures near their respective equilibrium consolute points have been observed to be suppressed. The systems studied included t-amyl chloride in isobutyric acid water (upper consolute temperature), and 3-chloro-3-methylpentane in 2-butoxyethanol water (lower consolute temperature). The slowing effect occurred within a few tenths of a degree on either side of the consolute temperature. 

Additional experiments with high concentrations of 2,4-D butoxyethanol ester with and without buffers showed no difference in degradation rates which confirmed the observations made in field experiments. Based on interpretation of results of these laboratory studies, combinations of buffers, anaerobic sludge, aerobic slime, light and constant mixing were not considered to be necessary for small and intermediate sized disposal systems. 

Thermodynamics of the Mixed Micellar System Sodium Decanoate-2-Butoxyethanol in Water at 25 ° C... 

Medium-chain alcohols such as 2-butoxyethanol (BE) exist as microaggregates in water which in many respects resemble micellar systems. Mixed micelles can be formed between such alcohols and surfactants. The thermodynamics of the system BE-sodlum decanoate (Na-Dec)-water was studied through direct measurements of volumes (flow denslmetry), enthalpies and heat capacities (flow microcalorimetry). Data are reported as transfer functions. The observed trends are analyzed with a recently published chemical equilibrium model (J. Solution Chem. 13,1,1984). By adjusting the distribution constant and the thermodynamic property of the solute In the mixed micelle. It Is possible to fit nearly quantitatively the transfer of BE from water to aqueous NaDec. The model Is not as successful for the transfert of NaDec from water to aqueous BE at low BE concentrations Indicating self-association of NaDec Induced by BE. The model can be used to evaluate the thermodynamic properties of both components of the mixed micelle. 

Thus the enthalpy of mixing is a key quantity for a system to show a UCST. For the other excess functions, e.g. VE and Cp, there are no restrictions, but generally at a UCST, Cf< 0 and VE > 0, while at a LCST, Cp > 0 and VE < 0 (Rowlinson, 1969). If Cf is negative at an LCST and remains so as the temperature increases, then HE and SE may change in such a way that the conditions for a UCST are met. Such systems show a closed solubility loop. The mixture water + nicotine is a classic example of such a system. The behaviour of another example, the mixture water + 2-butoxyethanol, is shown in Fig. 29 (Ellis, 1967). 

Fig. 5. Intensity of the scattered light (I90) as a function of temperature. System 2 Butoxyethanol/water at 172 bar, x(H20) = 0.975 Line represents intensity averages every 10 sec.

The analysis of the relaxation data according to the Aniansson model to obtain estimates of k is not straightforward in all cases. Whereas the third term within the brackets of eq 4 can be shown to be < 1 for systems contaiiung propanol, and therefore can be ignored, this is not the case for systems containing butanol, pentanol and 1-butoxyethanol. For most of the conditions examined in the latter cases, a Cm/C 1 and eq 4 simplifies to yield... 

The hydrocarbons (all of the above except 2-butoxyethanol) are all neurotoxicJ2°l 2-Butoxyethanol targets the respiratory system, liver, kidneys, lymphoid system, and bloodJ13 Some studies have reported that new carpet VOC emissions are sufficiently low to not adversely affect indoor air quality nor impact the human respiratory system or CNSJ20,24 Other studies, however, have reported that human exposures to new carpet emissions at very low concentrations of both the individual chemicals and total VOCs do induce serious respiratory and CNS effectsJ25,2 The diametrically opposite conclusions reached by the two sets of studies can be attributed to... 

Butoxyethanol and 2-butoxyethanol acetate do not seem to have effects on the immune system of animals. Like many solvents, 2-butoxyethanol causes nervous system effects in animals. 

No studies were located regarding musculoskeletal, endocrine, dermal, or body weight effects in humans after inhalation exposure to 2-butoxyethanol. No studies were located regarding any systemic effects in humans, or regarding gastrointestinal, musculoskeletal, dermal, or ocular effects in animals after inhalation exposure to 2-butoxyethanol acetate. Available data pertaining to systemic effects of each compound are presented below. 

Other Systemic Effects. Decreased water consumption was seen in Fischer 344 rats ingesting 2-butoxyethanol at 152 mg/kg/day (females) and 242 mg/kg/day (males) in drinking water for 2 weeks (NTP 1993). In B6C3Fi mice treated similarly, decreased water consumption was seen in female mice at... 

Information on immunological effects of 2-butoxyethanol in animals exposed orally to 2-butoxyethanol is limited to one acute and one intermediate study. Male Fischer 344 rats were immunized with trinitrophenyl-lipopolysaccharide (TNP-LPS) and then dosed by gavage (4 and 28 hours after immunization) to 0, 50, 100, 200, or 400 mg/kg/day 2-butoxyethanol in distilled water for 2 consecutive days (Smialowicz et al. 1992). Three days later, the primary plaque-forming cell (PFC) response to TNP-LPS was determined. The PFC response to TNP-LPS was used to evaluate B-l miphocyte antibody production. No toxic effect of 2-butoxyethanol in the immune system was detected. In Sprague-Dawley rats, in which males received doses of 180 or 506 mg/kg/day 2-butoxyethanol and females received doses of 204 or 444 mg/kg/day 2-butoxyethanol in the drinking water for 21 days, serum samples were... 

Other notable systemic effects observed in humans exposed to high doses include respiratory depression, metabolic acidosis, alteration of cardiac rhylhin, and hematuria. In animals, hepatic and renal toxicity have been observed, including hepatic necrosis and hemoglobin casts in the renal tubules and hematuria. Increased spleen weight and splenic congestion have been observed after 2-butoxyethanol exposure in animals. Many of the effects observed may be due to the hemolytic effects of 2-butoxyethanol. 

The information on immunological effects of 2-butoxyethanol in animals consists of the following findings no effect on the immune system was found in rats at gavage doses of 400 mg/kg/day for 2 days following immunization with trinitrophenyl-lipopolysaccharide (TNP-LPS) (Smialowicz et al. 1992) and no IgG change compared with controls in antibody production or delayed-type hypersensitivity response... 

For 2-butoxyethanol acetate, data describing health effects in humans are limited to a dennal irritancy study (Figure 2-13). Animal studies with 2-butoxyethanol acetate are extremely hmited but provide some information on death acute-duration systemic effects and immunological and lymphoreticular, neurological, reproductive, and developmental effects after inhalation and oral exposure. In addition, information exists on intennediate-duration systemic effects after inhalation exposure. Dennal studies in animals provide information on death acute-duration systemic effects and immunological and lymphoreticular, neurologic, and reproductive effects. It should be noted that the information for 2-butoxyethanol acetate is contained in only two studies. 

Olin 1976 Union Carbide 1980a, 1980b) to 2-butoxyethanol. Studies have shown that rats are particularly sensitive to the hematotoxic effects of 2-butoxyethanol, compared to humans (Bartnik et al. 1987 Ghanayem and Sullivan 1993 Udden 1994). However, since numerous data are available regarding systemic effects in animals, more studies on species-specific systemic effects, particularly hematotoxicity, after acute-duration exposure by inhalation, oral, and dermal routes in animals would not be particularly useful. Doses or concentrations that would result in hematological effects in humans are not known, and it would be unethical to find out by direct experiments on humans however, there may be a place for more in vitro experiments on fresh human blood. 

The hematological system is the primary target for 2-butoxyethanol toxicity. Therefore, further animal studies designed to confirm and extend the data of Dodd et al. (1983) for inhalation exposure, and animal... 

No studies were located regarding health effects in humans or animals after chronic inhalation, oral, or dermal exposure or in animals after chronic inhalation exposure to 2-butoxyethanol or 2-butoxyethanol acetate. The primary targets for adverse systemic effects of 2-butoxyethanol following acute- and intermediate-duration exposure are the hematological and renal systems. Since chronic low-level... 

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