Advanced

Emulsion Condensation Polymerization in Dispersed Aqueous Media. Interfacial Reactions and Nanoparticle Formation

Bailey Jönsson, Johanna LU ; Muellner, Markus LU ; Piculell, Lennart LU and Karlsson, Ola LU (2013) In Macromolecules 46(22). p.9104-9113
Abstract
The polycondensation of polyesters from C-12 monomers at 95 degrees C in aqueous o/w emulsions, stabilized by acidic surfactants, has been studied in detail with a range of methods during the course of the reaction, resulting in a better understanding of the underlying reaction mechanisms. Comparisons of different surfactants, and effects of added NaCl, demonstrate that the reaction site is located at the interface between the hydrophobic core of the emulsion droplets and the surrounding water and that the reaction rate is dependent on the local concentration of oxonium ions at the reaction site. The equilibrium conversion achieved at long reaction times is, however, independent of the choice of surfactant or addition of salt, and the... (More)
The polycondensation of polyesters from C-12 monomers at 95 degrees C in aqueous o/w emulsions, stabilized by acidic surfactants, has been studied in detail with a range of methods during the course of the reaction, resulting in a better understanding of the underlying reaction mechanisms. Comparisons of different surfactants, and effects of added NaCl, demonstrate that the reaction site is located at the interface between the hydrophobic core of the emulsion droplets and the surrounding water and that the reaction rate is dependent on the local concentration of oxonium ions at the reaction site. The equilibrium conversion achieved at long reaction times is, however, independent of the choice of surfactant or addition of salt, and the state of thermodynamic equilibrium is discussed thoroughly. Interestingly, a fraction of numerous "nanoparticles" (droplets in the size range <= 100 nm) have been found to develop in addition to the original fraction of droplets in the 10 mu m size range. It is suggested that these nanoparticles are formed when monomers dissolved in the aqueous phase undergo an acid-catalyzed reaction to generate water-insoluble oligomers. Once the nanoparticles are formed, the reactions in them proceed with a reaction mechanism similar to emulsion polymerization. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Macromolecules
volume
46
issue
22
pages
9104 - 9113
publisher
The American Chemical Society (ACS)
external identifiers
  • wos:000327752900039
  • scopus:84888602849
ISSN
0024-9297
DOI
10.1021/ma401799g
language
English
LU publication?
yes
id
49549e6b-8fe3-4f80-8edb-7f5ff08a9d92 (old id 4273132)
date added to LUP
2014-01-31 09:43:35
date last changed
2019-03-08 01:08:59
@article{49549e6b-8fe3-4f80-8edb-7f5ff08a9d92,
  abstract     = {The polycondensation of polyesters from C-12 monomers at 95 degrees C in aqueous o/w emulsions, stabilized by acidic surfactants, has been studied in detail with a range of methods during the course of the reaction, resulting in a better understanding of the underlying reaction mechanisms. Comparisons of different surfactants, and effects of added NaCl, demonstrate that the reaction site is located at the interface between the hydrophobic core of the emulsion droplets and the surrounding water and that the reaction rate is dependent on the local concentration of oxonium ions at the reaction site. The equilibrium conversion achieved at long reaction times is, however, independent of the choice of surfactant or addition of salt, and the state of thermodynamic equilibrium is discussed thoroughly. Interestingly, a fraction of numerous "nanoparticles" (droplets in the size range &lt;= 100 nm) have been found to develop in addition to the original fraction of droplets in the 10 mu m size range. It is suggested that these nanoparticles are formed when monomers dissolved in the aqueous phase undergo an acid-catalyzed reaction to generate water-insoluble oligomers. Once the nanoparticles are formed, the reactions in them proceed with a reaction mechanism similar to emulsion polymerization.},
  author       = {Bailey Jönsson, Johanna and Muellner, Markus and Piculell, Lennart and Karlsson, Ola},
  issn         = {0024-9297},
  language     = {eng},
  number       = {22},
  pages        = {9104--9113},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Macromolecules},
  title        = {Emulsion Condensation Polymerization in Dispersed Aqueous Media. Interfacial Reactions and Nanoparticle Formation},
  url          = {http://dx.doi.org/10.1021/ma401799g},
  volume       = {46},
  year         = {2013},
}