Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Investigations intothe crystallization of butyl paraben
KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. (Crystallization)
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In thisproject, solubility of butyl paraben in 7 puresolvents and 5 ethanol aqueous solvents has been determined at from 1 ℃to 50 ℃. Thermodynamic properties of butyl paraben have been measured by DifferentialScanning Calorimetey. Relationship between molar solubility of butyl paraben in6 pure solvents and thermodynamic properties has been analyzed. Thisrelationship suggests a method of estimating activity of solute at equilibrium fromcombining solubility data with DSC measurements. Then, activity coefficient accordingto the solubility at different temperatures can be estimated.

Duringthe solubility measurements in ethanol aqueous solvents, it is found that whenbutyl paraben is added into aqueous solutions with certain proportion ethanol,solutions separates into two immiscible liquid layers in equilibrium. Water andethanol are primary in top layer, while the butyl paraben is primary in bottomlayer, but the solution turns to cloudy when two layers of solution are mixed. Theaim of this work was to present the phase behaviour of liquid-liquid-phaseseparation for (butyl paraben + water + ethanol) ternary system from 1 ℃ to 50 ℃at atmospheric pressure. Thearea of liquid-liquid-phase separation region in the ternary phase diagram increaseswith the increasing temperature from 10 ℃to 50 ℃.

In thisstudy, more than several hundreds of nucleation experiments of butyl paraben havebeen investigated in ethyl acetate, propanol, acetone and 90% ethanol aqueoussolution. Induction time of butyl paraben has been determined at 3 differentsupersaturation levels in these solvents, respectively. Free energy ofnucleation, solid-liquid interfacial energy, and nuclei critical radius havebeen determined according to the classical nucleation theory. Statistical analysis ofinduction time reveals that the nucleation is a stochastic process with widevariation even at the same experiment condition. Butyl paraben nucleates most difficultlyin 90 % ethanol than in other 3 solvents, and most easily in acetone. The interfacialenergy of butyl paraben in these solvents tends to increasing with decreasemole fraction solubility in these solvents.

Coolingcrystallizations with different proportions of butyl paraben, water and ethanolhave been observed by Focused Beam Reflectance Method, Parallel VirtualMachine, and On-line Infrared. The FBRM, IR curves and the PVM photos show someof the solutions appeared liquid-liquid phase separation during coolingcrystallization process. The results suggest that if solutions went throughliquid-liquid phase separation region during the cooling crystallizationprocess the distribution of crystals crystal was poor. Droplets from solutions withsame proportion butyl paraben but different proportions of water and ethanolhave been observed under microscope. Induction time of the droplets has been determinedunder the room temperature. Droplets from top layer or bottom layer of solutionwith liquid-liquid phase separation on small glass or plastic plates were alsoobserved under microscope. The microscope photos show that the opposite flows ofcloudy solution on the glass and the plastic plate before nucleation. The resultsof the cooling and evaporation crystallization experiments both revealed thatnucleation would be prevented by the liquid-liquid phase separation.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology , 2011. , x, 65 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2011:43
Keyword [en]
Butyl paraben, Solubility, Thermodynamic, Activity, Activity coefficient, Second order correlation, Liquid-liquid phase separation, Ternary phase diagram, Nucleation, Induction time, Free energy, Interfacial energy, Nuclei critical radius Cooling crystallization, Evaporation crystallization
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-34051ISBN: 978-91-7501-028-1 (print)OAI: oai:DiVA.org:kth-34051DiVA: diva2:418916
Presentation
2011-06-10, K2, Teknikringen 28, KTH, Stockholm, 16:20 (English)
Opponent
Supervisors
Note
QC 20110630Available from: 2011-06-30 Created: 2011-05-24 Last updated: 2012-03-28Bibliographically approved
List of papers
1. Solubility of Butyl Paraben in Methanol, Ethanol, Propanol, Ethyl Acetate, Acetone, and Acetonitrile
Open this publication in new window or tab >>Solubility of Butyl Paraben in Methanol, Ethanol, Propanol, Ethyl Acetate, Acetone, and Acetonitrile
2010 (English)In: Journal of Chemical and Engineering Data, ISSN 0021-9568, E-ISSN 1520-5134, Vol. 55, no 11, 5091-5093 p.Article in journal (Refereed) Published
Abstract [en]

The solubility of butyl paraben (butyl 4-hydroxybenzoate) have been determined in methanol, ethanol, propanol, acetone, ethyl acetate, and acetonitrile in the temperature range of (10 to 50) C by the gravimetric method. The order of the solubility of butyl paraben in the different solvents as mass fraction at 20 C is: methanol > ethanol > acetone > propanol > ethyl acetate > acetonitrile. In terms of mole fraction solubility, the corresponding order is acetone > propanol > ethanol > ethyl acetate > methanol > acetonitrile, which shows that both nonpolar and polar groups of the paraben molecule influence the solubility in the different solvents.

Keyword
published literature, thermodynamics, health
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-27367 (URN)10.1021/je1006289 (DOI)000284017600083 ()2-s2.0-78449307514 (Scopus ID)
Note
QC 20101214Available from: 2010-12-14 Created: 2010-12-13 Last updated: 2017-12-11Bibliographically approved
2. Thermodynamics of molecular solids in organic solvents
Open this publication in new window or tab >>Thermodynamics of molecular solids in organic solvents
2012 (English)In: Journal of Chemical Thermodynamics, ISSN 0021-9614, E-ISSN 1096-3626, Vol. 48, 150-159 p.Article in journal (Refereed) Published
Abstract [en]

The thermodynamics of solid-solution solubility are examined using data for two different compounds: butyl paraben and benzoic acid. Solubility data in different solvents are used to estimate melting properties of the pure solid solutes, and are used to estimate the solid state Gibbs free energy relative to the super cooled melt. The relation to melting data experimentally determined is analysed, and solution activity coefficients are calculated. The work shows that there is a strong relation between solid-liquid solubility data and thermodynamic data of the pure solute. For these compounds, the melting temperature of the pure solute can be fairly accurately estimated by extrapolation of solid-liquid solubility data up to mole fraction equal unity. The estimation of the melting enthalpy is less successful showing deviations in the order of 20% to 30% from the experimental values determined by differential scanning calorimetry. For butyl paraben and benzoic acid, the best estimation of the solid state Gibbs free energy is obtained if DSC determination of melting properties is combined with an estimation of the melt-solid heat capacity difference versus temperature relation by correlation to solubility data.

Keyword
Butyl paraben, Benzoic acid, Thermodynamic, Solubility, Heat capacity, Melting temperature, Enthalpy of fusion, Correlation, Optimisation
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-87081 (URN)10.1016/j.jct.2011.12.015 (DOI)000300416700021 ()2-s2.0-84862785488 (Scopus ID)
Note
QC 20120627Available from: 2012-02-14 Created: 2012-02-14 Last updated: 2017-12-07Bibliographically approved
3. Crystallization of butyl paraben in mixtures of water and ethanol
Open this publication in new window or tab >>Crystallization of butyl paraben in mixtures of water and ethanol
(English)Manuscript (preprint) (Other academic)
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-35449 (URN)
Note

QS 2013

Available from: 2011-06-30 Created: 2011-06-30 Last updated: 2013-05-15Bibliographically approved

Open Access in DiVA

fulltext(2253 kB)438 downloads
File information
File name FULLTEXT01.pdfFile size 2253 kBChecksum SHA-512
ef6cc4d5e40375a39f033c87a8da462355eba206763805ceabf199e08ae2d50d7943f69a77a2dfd8760aa93658955e9d61c90a6385d970f669144be9fe5a8c80
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Yang, Huaiyu
By organisation
Transport Phenomena
Chemical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 438 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 241 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf