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Nonequilibrium Particle Morphology Development in Seeded Emulsion Polymerization. II. Influence of Seed Polymer Tg.

Karlsson, Lina LU ; Karlsson, Ola LU and Sundberg, D C (2003) In Journal of Applied Polymer Science 90(4). p.905-915
Abstract
Most structured latex particles are formed in the nonequilibrium state as a result of the reaction kinetics proceeding faster than the phase separation kinetics. Of the many factors controlling such morphologies, the polarity and glass transition temperature (Tg) of the seed polymer are important. In order to study the direct effect of the seed polymer Tg on morphology, we produced a series of poly(methyl methacrylate)/poly(methyl acrylate) seed copolymers having glass points between 52 and 98°C, and particle sizes between 320 and 390 nm. We then used styrene as a second-stage monomer reacting in both the batch and semibatch process modes, and utilized reaction temperatures (Tr) between 50 and 70°C. Monomer feed rates were varied between... (More)
Most structured latex particles are formed in the nonequilibrium state as a result of the reaction kinetics proceeding faster than the phase separation kinetics. Of the many factors controlling such morphologies, the polarity and glass transition temperature (Tg) of the seed polymer are important. In order to study the direct effect of the seed polymer Tg on morphology, we produced a series of poly(methyl methacrylate)/poly(methyl acrylate) seed copolymers having glass points between 52 and 98°C, and particle sizes between 320 and 390 nm. We then used styrene as a second-stage monomer reacting in both the batch and semibatch process modes, and utilized reaction temperatures (Tr) between 50 and 70°C. Monomer feed rates were varied between flooded and starve-fed conditions. The equilibrium morphology for these composite particles is an inverted core-shell structure, but all morphologies obtained in our experiments were nonequilibrium. Under monomer starved conditions only core-shell structures were formed when (Tr-Tg) < 0, but significant penetration of the polystyrene into the acrylic core occurs when (Tr-Tg) > 15°C. These results are reasonably well predicted using the fractional penetration model developed earlier. © 2003 Wiley Periodicals, Inc. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
glass, diffusion, nonequilibrium, latex, morphology, transition temperature, core-shell
in
Journal of Applied Polymer Science
volume
90
issue
4
pages
905 - 915
publisher
John Wiley & Sons
external identifiers
  • wos:000185091100002
  • scopus:0141459665
ISSN
1097-4628
DOI
10.1002/app.12644
language
English
LU publication?
yes
id
c677b0f1-24ff-4b86-9163-ba988407ec89 (old id 129523)
date added to LUP
2007-07-13 12:45:47
date last changed
2018-01-07 05:31:41
@article{c677b0f1-24ff-4b86-9163-ba988407ec89,
  abstract     = {Most structured latex particles are formed in the nonequilibrium state as a result of the reaction kinetics proceeding faster than the phase separation kinetics. Of the many factors controlling such morphologies, the polarity and glass transition temperature (Tg) of the seed polymer are important. In order to study the direct effect of the seed polymer Tg on morphology, we produced a series of poly(methyl methacrylate)/poly(methyl acrylate) seed copolymers having glass points between 52 and 98°C, and particle sizes between 320 and 390 nm. We then used styrene as a second-stage monomer reacting in both the batch and semibatch process modes, and utilized reaction temperatures (Tr) between 50 and 70°C. Monomer feed rates were varied between flooded and starve-fed conditions. The equilibrium morphology for these composite particles is an inverted core-shell structure, but all morphologies obtained in our experiments were nonequilibrium. Under monomer starved conditions only core-shell structures were formed when (Tr-Tg) &lt; 0, but significant penetration of the polystyrene into the acrylic core occurs when (Tr-Tg) &gt; 15°C. These results are reasonably well predicted using the fractional penetration model developed earlier. © 2003 Wiley Periodicals, Inc.},
  author       = {Karlsson, Lina and Karlsson, Ola and Sundberg, D C},
  issn         = {1097-4628},
  keyword      = {glass,diffusion,nonequilibrium,latex,morphology,transition temperature,core-shell},
  language     = {eng},
  number       = {4},
  pages        = {905--915},
  publisher    = {John Wiley & Sons},
  series       = {Journal of Applied Polymer Science},
  title        = {Nonequilibrium Particle Morphology Development in Seeded Emulsion Polymerization. II. Influence of Seed Polymer Tg.},
  url          = {http://dx.doi.org/10.1002/app.12644},
  volume       = {90},
  year         = {2003},
}