Analytical Sciences

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## Central Report Index (CRI) Report

The Dow Chemical Company

**Title**

Extrapolation of Vapor Pressure Data Using the Antoine Equation

**Author(s) and Userid(s)** 

Crosthwaite, Jacob (JM) (U393454); Srivastava, Rakesh (R) (U081611)

**Final Reviewer and Userid Date Issued**  **Lab Report Code** Pasztor Jr, Andew (AJ) (U 075055 ); Killebrew, Tina (TM) (U366965) January 3, 2012

**Abstract**

The original toxicity work on divinylbenzene dioxide (DVBDO or Epoxide 12) and associated characterization was done on an 80% purity product, where the primary impurities were ethylvinylbenzene oxide (EVBO) and divinylbenzene monoxide (DVBMO). The vapor pressure of the 80% product at 25 °C was measured by an external contract laboratory using a vapor pressure balance. However, the value reported for the sample was 4.3 Pa (0.032 mmHg) at 25 °C, which is higher than expected based on the extrapolated vapor pressure data for the three major components DVBDO, EVBO, and DVBMO from an earlier Dow study. Vapor pressure data had been measured for these three components for regressing Antoine equation parameters, which were used for extrapolating vapor pressure data at 25 °C. To address this issue, this study was conducted to evaluate the use of Antoine Equation constants from vapor pressure data of high boiling compounds (normal boiling points greater than 200 °C) for extrapolating vapor pressure data at lower temperatures such as 25 °C from measurements conducted at higher temperatures. Vapor pressure data were obtained for three test components, tetradecane, 1-dodecanol, and sulfolane, which have comparable volatility to DVBDO and experimental vapor pressure data at temperatures near 25 °C. The vapor pressure data of these three compounds were measured and the data correlated to the Antoine and Wagner equations for extrapolation to low er

temperatures near ambient. Predicted vapor pressure data using the correlation parameters were compared to experimental data for evaluating the accuracy of the extrapolated vapor pressure data. The Antoine equation constrained by the Thomson’s Rule provided the best fit compared to the experimental data near 25 °C, with an expected deviation of ±25%.Analytical Sciences

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### NOTIFICATION LIST

This list indicates people to be notified by the authors when this report is available from CRI.

See the RIC website for more information on the notification list.

Crosthwaite, Jacob (JM) Srivastava, Rakesh (R) Pasztor, Andrew (AJ) Killebrew, Tina (TM) Jean, David (DL) Krieg, David (DW) Treble, Imogene (IE)

.DL AS R&D- LT

Databook: 200900916



### TABLE OF CONTENTS

INTRODUCTION

........................................................................................................................................... 3

EXPERIMENTAL

.......................................................................................................................................... 3

Materials

.................................................................................................................................................... 3 Vapor Pressure

.......................................................................................................................................... 3

RESULTS & DISCUSSION

........................................................................................................................... 5

CONCLUSIONS & RECOMMENDATIONS

.................................................................................................. 6

REFERENCES

.............................................................................................................................................. 6

APPENDIX A. EMAIL CONVERSATIONS WITH HARLAN

........................................................................ 8



### LIST OF TABLES

Table 1. Vapor Pressure of Tetradecane

..................................................................................................... 5 Table 2. Vapor Pressure of 1-Dodecanol

..................................................................................................... 5 Table 3. Vapor Pressure of Sulfolane

.......................................................................................................... 5 Table 4. Antoine Equation Parameters (Unconstrained and Constrained by Thomson’s Rule) for Tetradecane, 1-Dodecanol, and Sulfolane

................................................................................................... 5 Table 5. Wagner Equations Parameters for Tetradecane, 1-Dodecanol, and Sulfolane

............................ 5 Table 6. Comparison of Predicted Vapor Pressure from Antoine and Wagner Equation Regressions to Experimental Data (DIPPR)

.......................................................................................................................... 6



### LIST OF FIGURES

Figure 1. Photograph of the Stirred Vapor Pressure Ebulliometer

.............................................................. 4Analytical Sciences

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### INTRODUCTION

The original toxicity work and associated characterization on divinylbenzene dioxide (DVBDO or Epoxide 12) was done on an 80% purity product, where the primary impurities were ethylvinylbenzene oxide (EVBO) and divinylbenzene monoxide (DVBMO). The vapor pressure of the 80% product at 25 °C was measured by Harlan, an external contract laboratory, using a vapor pressure balance 1 . The value reported for the sample was 4.3 Pa (0.032 mmHg) at 25 °C, which is higher than expected based on the extrapolated vapor pressure data for the three major components DVBDO, EVBO, and DVBMO 2 . The method used by Harlan is good for pure components, but will be inaccurate for mixtures. Based on conversations with Harlan personnel (see Appendix A for more details), the value reported for the sample would be the vapor pressure of the least volatile component in the mixture and not be representative of the vapor pressure of the test sample, providing misleading data for risk assessment on environmental

emissions 3 . This observation was confirmed as the extrapolated vapor pressure of DVBMO (an impurity in the 80% sample) at 25 °C is 0.029 mmHg, which matches the reported value by Harlan. This study was conducted to evaluate the use of Antoine Equation constants for extrapolating vapor pressure data at lower temperatures such as 25 °C from measurements conducted at higher temperatures.

Vapor pressure data for DVBDO, EVBO, and DVBMO were measured internally using either an ebulliometric or GC method at higher temperatures (70 to 200 °C) and fit to the Antoine equation (constrained by the Thomson’s Rule) 2 . The Antoine equation parameters were then used to calculate the vapor pressure at 25 °C. To assess the accuracy of extrapolating vapor pressure data at 25 °C using Antoine equation parameters, vapor pressure data were obtained for three test components using the stirred-flask ebulliometer. Tetradecane, 1-dodecanol, and sulfolane were chosen as test materials based on comparable volatility to DVBDO and the availability of vapor pressure data at temperatures near 25 °C. The vapor pressure of these three compounds was measured and the data correlated to the Antoine and Wagner equations for extrapolation to low temperatures near ambient. Predicted vapor pressure data using the correlation parameters were compared to experimental data for evaluating the accuracy of the extrapolated vapor pressure data.



### EXPERIMENTAL

Materials

Tetradecane (puriss., olefin free, Lot# BCBF0800V, 99.5%), 1-dodecanol (ACS Reagent, Lot# MKBF9576V, 99.3%), and sulfolane (Lot# MKBD8843V, 99.9%) were supplied by Aldrich.

Vapor Pressure

Vapor pressure data were measured using ASTM method E1719 4 in the glass still shown in Figure 1. This still consists of a 250- filter flask attached to a condenser. The temperature of the liquid in the flask was measured by a platinum resistance thermometer inserted into the liquid with an accuracy of ± 0.05 °C. The temperature was recorded by a computerized data acquisition system. The still was charged through the top of the flask. After charging, the still was evacuated and refilled with dry nitrogen to remove moisture and oxygen. The base of the still was then immersed in a silicone bath and the oil

bath was heated.

The liquid in the still was stirred vigorously by a large magnetic stirrer located beneath the oil bath. As the bath was heating, the pressure was set at the first desired value for the vapor pressure measurements. The pressure was controlled and measured by a Mensor pressure controller with an accuracy of ±

0.025%

. The bath was heated until the material in the still began to reflux. The bath temperature was then increased until the reflux rate was approximately one drop per second. After the material in the still was refluxing at steady state conditions, the bath temperature was raised or lowered by one degree at constant condenser pressure. The temperature of the liquid in the still should remain constant even if the bath temperature changes when the system is operating at equilibrium. The usual cause for non-Analytical Sciences

DOW CONFIDENTIAL - Do not share without permission 4 of 12 TMTrademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow equilibrium operation is insufficient stirring or not enough reflux. If the temperature in the still responded to a change in the bath temperature, the agitation in the still was increased or the bath temperature was increased until equilibrium conditions were reached. For this work, the temperature of the oil bath was controlled by a Hart Model 2100 temperature controller at approximately 10 °C above the boiling temperature of the sample. The temperature in the still was monitored until it was stable. An average temperature from several minutes of operation was then recorded in the lab book. After the measurement, the pressure was increased to the next desired value, the bath temperature was increased, and the system was allowed to re-equilibrate.

Figure 1. Photograph of the Stirred Vapor Pressure Ebulliometer

The vapor pressure data were correlated to the Antoine equation and Wagner equation for extrapolation of vapor pressure data to 25 °C. The Antoine and Wagner equations are shown in equations 1 and 2, respectively.

(1)

(2)

(3a) (3b)

where: P = vapor pressure t = temperature (°C) T = temperature (K)

P

c = critical pressure

T

c = critical temperature (K) A, B, C = Antoine equation parameters

C 1 , C 2 , C 2 , C 3 = Wagner equation parametersAnalytical Sciences

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### RESULTS & DISCUSSION

Vapor pressure data for tetradecane, 1-dodecanol, and sulfolane are shown in Tables 1-3, respectively. The data match the expected vapor pressure data within the listed uncertainty from the DIPPR database 5

for all three components. The measured vapor pressure data were correlated to the Antoine equation using the Thermal ANTOINE program and to the Wagner equation using AspenPlus. The details of the Antoine equation fitting program can be found on the Dow Intranet 6 . For the Antoine equation regression, two regressions were made: 1) an unconstrained fit and 2) using the Thomson’s rule to constrain the C value. The Thomson rule constrains the C value in the Antoine equation based on the normal boiling point of the sample, providing an approximately correct curvature for the data. Antoine equation constants from both regressions for the three components are shown in Table 4, and Wagner equation parameters and constants are shown in Table 5. The critical temperature and pressure for the three components were obtained from the DowPure Database using DowPPDS 7

.

Table 1. Vapor Pressure of

Tetradecane

T (°C) P (mmHg)

109.918 5

123.041 10

143.104 25

160.491 50

171.63 75

180.023 100

186.834 125

192.639 150

197.567 175

Italized data not used in

Correlations Table 2. Vapor Pressure of

1-Dodecanol

T (°C) P (mmHg)

127.298 5

139.517 10

153.389 20

169.229 40

179.411 60

187.098 80

193.36 100

198.558 120 Table 3. Vapor Pressure of

Sulfolane

T (°C) P (mmHg)

127.907 5

142.528 10

159.058 20

169.681 30

177.651 40

184.089 50

189.536 60

194.268 70

198.335 80

Table 4. Antoine Equation Parameters (Unconstrained and Constrained by Thomson’s Rule) for Tetradecane, 1-Dodecanol, and Sulfolane

Compound Unconstrained Constrained by Thomson's Rule

A B C A B C

Tetradecane 6.55072 1434.67 135.303 7.55531 2069.46 192.45

1

- Dodecanol 6.14666 1147.48 83.3671 8.22934 2393.57 191.323

Sulfolane 6.45813 1538.77 139.307 7.25353 2055.73 186.02

Table 5. Wagner Equations Parameters for Tetradecane, 1-Dodecanol, and Sulfolane

Compound C1 C2 C3 C4 T

c (K) P

c (mmHg)

Tetradecane

- 2.91963

- 13.89285 20.36029

- 83.3998 693.15 12166

1

- Dodecanol 6.004256

- 34.97373 52.098

- 175.489 719.4 14956.2

Sulfolane 19.89514

- 58.34899 66.02761

- 91.9523 855 37694.3Analytical Sciences

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Component T (°C) P exp (mmHg) Antoine

Constrained by

Thomson's Rule Antoine

Unconstrained Wagner

P (mmHg) % Diff P (mmHg) % Diff P (mmHg) % Diff

Tetradecane 6.4 2.00E

- 03 1.41E

- 03

- 29.7 2.67E

- 04

- 86.7 8.28E

- 05

- 95.9

Tetradecane 12.7 4.00E

- 03 2.94E

- 03

- 26.6 7.20E

- 04

- 82.0 2.65E

- 04

- 93.4

Tetradecane 16.5 6.00E

- 03 4.48E

- 03

- 25.3 1.26E

- 03

- 79.0 5.10E

- 04

- 91.5

Tetradecane 19.3 8.00E

- 03 6.06E

- 03

- 24.3 1.87E

- 03

- 76.7 8.08E

- 04

- 89.9

Tetradecane 21.6 1.00E

- 02 7.71E

- 03

- 22.9 2.55E

- 03

- 74.5 1.16E

- 03

- 88.4

Tetradecane 28.8 2.00E

- 02 1.59E

- 02

- 20.4 6.43E

- 03

- 67.8 3.40E

- 03

- 83.0

Tetradecane 36.4 4.00E

- 02 3.25E

- 02

- 18.6 1.57E

- 02

- 60.8 9.50E

- 03

- 76.3

1

- Dodecanol 30 2.10E

- 03 2.60E

- 03 23.7 1.06E

- 04

- 95.0 3.20E

- 05

- 98.5

1

- Dodecanol 40 5.86E

- 03 7.62E

- 03 30.1 7.00E

- 04

- 88.0 2.71E

- 04

- 95.4

Sulfolane 27.4 5.57E

- 03 4.18E

- 03

- 25.0 1.69E

- 03

- 69.7 4.65E

- 04

- 91.6

Sulfolane 55.02 5.53E

- 02 5.31E

- 02

- 4.0 3.46E

- 02

- 37.4 1.98E

- 02

- 64.1

Table 6 contains vapor pressure data for tetradecane, 1-dodecanol, and sulfolane extrapolated to temperatures near 25 °C. The extrapolated data were compared with experimental data obtained from

the DIPPR Diadem database 5 , using only the “Accepted” data points. The parameters from the three regressions were used to predict the vapor pressure at the experimental temperatures for comparison to the experimental vapor pressure data (in terms of percent deviation). The Antoine regression constrained using the Thomson’s rule provided the best fit of the experimental data near 25 °C, with percent deviations around ± 25% between the experimental and extapolated data near 25 °C. The deviation of ± 25% would be expected when extrapolating down to 25 °C for similar high boiling components using vapor pressure data between 100 to 200 °C, while the expected uncertainty within the experimental data set would be considerable lower (typically less than 5%). Th e better fit was expected since constraining the vapor pressure data with Thomson’s rule helps provide a better curvature of the pressure-temperature dataset over a larger range up to the normal boiling point. The other two fits were both unconstrained and had significantly higher deviations at lower temperatures, with percent deviations of 75 to 100%. Based on the results on this study, it is recommended that the Antoine equation constrained by Thomson’s rule be used for all regressions of vapor pressure data below 200 mmHg.



### CONCLUSIONS & RECOMMENDATIONS

Vapor pressure data for tetradecane, 1-dodecanol, and sulfolane were measured and regressed to the Antoine and Wagner equations. The regression parameters were then used to predict vapor pressure data for comparison to experimental data near 25 °C. The Antoine equation regression constrained by the Thomson’s rule provided the best fit relative to the experimental data, with deviations of ± 25%. The vapor pressure data for DVBDO, EVBO, and DVBMO in the original report were regressed using the Antoine Equation constrained by Thomson’s rule. So, the uncertainty in the predicted vapor pressure for these components (4.23*10 -4 mmHg for DVBDO; 4.69*10 -3 mmHg for EVBO; 2.93*10 -2 mmHg for DVBMO) in the original report is expected to be about ± 25%.



### REFERENCES

1. Atwal, S. S.; Tremain, S. P., “Reaction mass of bis(epoxyethyl)benzene and (ethylphenyl)oxirane: Determination of Hazardous Physico-chemical Properties”, Project Number 0044/1411, Harlan Larboratories, Shardlow, Derbyshire, United Kingdom (2009).Analytical Sciences

DOW CONFIDENTIAL - Do not share without permission 7 of 12 TMTrademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow 2. Alkhawaldeh, A., Fowler, T., Jean, D., Pham, K., Solis, J., Srivastava, R., “Distillation and Physical Properties Measurements for Divinylbenzene Dioxide, Divinylbenzene Monoxide, and Ethylvinylbenzene Oxide”, CRI Report# EPI N-2010-022 (2010).

3. Anna Lojakowska, email communication, Oct. 19, 2011.

4. ASTM E 1719, “Standard Test Method for Vapor Pressure of Liquids by Ebulliometry”, Annual Book

of ASTM Standards , Vol. 14.02, American Society for Testing and Materials International, West Conshohocken, PA, (2004).

5. DIPPR Diadem, Version 5.2.2.

6. http://analytical.intranet.dow.com/rctapp/programs/antoine.htm

. 7. Dow PPDS, Version 4.1.0.1.Analytical Sciences

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