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Polymer recycling in aqueous two-phase extractions using thermoseparating ethylene oxide-propylene oxide copolymers

Persson, Josefine; Kaul, Anita and Tjerneld, Folke LU (2000) In Journal of Chromatography. B 743(1-2). p.115-126
Abstract
This is a study on the recovery and recycling of copolymer in aqueous two-phase systems containing random copolymers of ethylene oxide (EO) and propylene oxide (PO). The random copolymers separate from water solution when heated above the lower critical solution temperature (LCST). The primary phase systems were composed of EOPO copolymer and hydroxypropyl or hydroxyethyl starch. After phase separation the upper EOPO phase was removed and subjected to temperature induced phase separation. Copolymers with different EO/PO compositions have been investigated, EO50PO50 [50% EO and 50% PO (w/w)], EO30PO70 and EO20PO80. The temperature required for thermoseparation decreases when the PO content of the copolymer is increased. The effect on the... (More)
This is a study on the recovery and recycling of copolymer in aqueous two-phase systems containing random copolymers of ethylene oxide (EO) and propylene oxide (PO). The random copolymers separate from water solution when heated above the lower critical solution temperature (LCST). The primary phase systems were composed of EOPO copolymer and hydroxypropyl or hydroxyethyl starch. After phase separation the upper EOPO phase was removed and subjected to temperature induced phase separation. Copolymers with different EO/PO compositions have been investigated, EO50PO50 [50% EO and 50% PO (w/w)], EO30PO70 and EO20PO80. The temperature required for thermoseparation decreases when the PO content of the copolymer is increased. The effect on the recovery of copolymer after addition of salts, a second polymer or protein was investigated. The added components increased the recovery of copolymer after thermoseparation, e.g., increased the amount copolymer separated from the water phase after thermoseparation. Recycling of copolymer and measurements of polymer concentrations in the primary top and bottom phases after repeated recycling steps was performed. The fluctuation in polymer concentration of the phases was very small after recycling up to four times. Partitioning of the proteins BSA and lysozyme was studied in primary phase systems after recycling of copolymer. The partition coefficients of total protein and lysozyme was not significantly changed during recycling of copolymer. More than 90% of the copolymer could be recovered in the thermoseparation step by optimising the temperature and time for thermoseparation. In repeated phase partitionings in EOPO-starch systems the EO50PO50 copolymer could be recovered to 77% including losses in primary system and thermoseparation, which is equivalent to a total copolymer reuse of 4.3 times. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Ethylene oxide–propylene oxide, Thermoseparating polymers
in
Journal of Chromatography. B
volume
743
issue
1-2
pages
115 - 126
publisher
Elsevier
external identifiers
  • scopus:0034705763
ISSN
1873-376X
DOI
10.1016/S0378-4347(00)00213-9
language
English
LU publication?
yes
id
b134b9d4-8298-4eb8-a08a-94b4461fff2b (old id 125149)
date added to LUP
2007-07-06 12:50:44
date last changed
2017-10-01 03:45:30
@article{b134b9d4-8298-4eb8-a08a-94b4461fff2b,
  abstract     = {This is a study on the recovery and recycling of copolymer in aqueous two-phase systems containing random copolymers of ethylene oxide (EO) and propylene oxide (PO). The random copolymers separate from water solution when heated above the lower critical solution temperature (LCST). The primary phase systems were composed of EOPO copolymer and hydroxypropyl or hydroxyethyl starch. After phase separation the upper EOPO phase was removed and subjected to temperature induced phase separation. Copolymers with different EO/PO compositions have been investigated, EO50PO50 [50% EO and 50% PO (w/w)], EO30PO70 and EO20PO80. The temperature required for thermoseparation decreases when the PO content of the copolymer is increased. The effect on the recovery of copolymer after addition of salts, a second polymer or protein was investigated. The added components increased the recovery of copolymer after thermoseparation, e.g., increased the amount copolymer separated from the water phase after thermoseparation. Recycling of copolymer and measurements of polymer concentrations in the primary top and bottom phases after repeated recycling steps was performed. The fluctuation in polymer concentration of the phases was very small after recycling up to four times. Partitioning of the proteins BSA and lysozyme was studied in primary phase systems after recycling of copolymer. The partition coefficients of total protein and lysozyme was not significantly changed during recycling of copolymer. More than 90% of the copolymer could be recovered in the thermoseparation step by optimising the temperature and time for thermoseparation. In repeated phase partitionings in EOPO-starch systems the EO50PO50 copolymer could be recovered to 77% including losses in primary system and thermoseparation, which is equivalent to a total copolymer reuse of 4.3 times.},
  author       = {Persson, Josefine and Kaul, Anita and Tjerneld, Folke},
  issn         = {1873-376X},
  keyword      = {Ethylene oxide–propylene oxide,Thermoseparating polymers},
  language     = {eng},
  number       = {1-2},
  pages        = {115--126},
  publisher    = {Elsevier},
  series       = {Journal of Chromatography. B},
  title        = {Polymer recycling in aqueous two-phase extractions using thermoseparating ethylene oxide-propylene oxide copolymers},
  url          = {http://dx.doi.org/10.1016/S0378-4347(00)00213-9},
  volume       = {743},
  year         = {2000},
}