| Titre : | Comparison of temperature effects on the salting out of poly(ethylene glycol) versus poly(ethylene oxide)−poly(propylene oxide) random copolymer (2010) |
| Auteurs : | Meghna Dilip, Auteur ; Scott T. Griffin, Auteur ; Scott K. Spear, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 49 N° 5, Mars 2010) |
| Article en page(s) : | pp. 2371–2379 |
| Note générale : | Industrial Chemistry |
| Langues : | Anglais |
| Tags : | Random Copolymer ; Poly(ethylene glycol) ; oxide) ; Poly(propylene Aqueous biphasic systems |
| Résumé : | In common with many poly(ethylene glycol)s (PEGs), a poly(ethylene oxide)−poly(propylene oxide) random copolymer (EO−PO, with EO/PO = 1:1.3) of molecular weight 3320 g·mol−1, known as Sunbright-3320 (SB-3320), can be salted out of aqueous solution using kosmotropic salts such as (NH4)2SO4 to form aqueous biphasic systems (ABSs) comprising upper polymer-rich and lower salt-rich aqueous phases. The effects of temperature on these liquid/liquid ABSs and related solid/liquid resin-based systems, where one end of the polymer has been covalently attached to a solid support, have been studied. Distribution ratios of NH499TcO4 were determined radiometrically at various polymer and salt concentrations and temperatures. SB-3320-grafted poly(styrene) resins exhibit opposite effects of variable-temperature partitioning compared to the SB-3320-based ABS. However, the results are complicated because of the conformational changes that are possible for the SB-3320 polymer. Enthalpy and entropy changes were found to be temperature-dependent. The differences observed between the distribution of 99TcO4− in EO−PO-based systems versus PEG-based systems can be attributed to the lower cloud point temperatures and probable conformational changes for the EO−PO systems. |
| Note de contenu : | Bibliogr. |
| ISSN : | 0888-5885 |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie901268m |
