Abstract
The degree of homogeneity and H-bond interaction in blends of low-molecular-mass poly(ethylene
glycols) (PEG, Mw = 400, 600, 1000) and poly(vinylpyrrolidone) (PVP, Mw =9×103) prepared in supercritical
CO2, ethanol and as physical mixtures were studied by differential scanning calorimetry (DSC),
Fourier-transform infrared (FTIR) spectroscopy and dynamic mechanical analysis (DMA) techniques.
Homogeneity of samples prepared in supercritical CO2 were greater than physically mixed samples,
but slightly less than ethanol-cast samples. PEG–PVP H-bond interaction was higher for ethanol-cast
blends when compared to blends prepared in supercritical CO2. This reduced interaction was attributed
to a combination of: (1) shielding of PEG–PVP H-bond interactions when CO2 is dissolved in the blend;
(2) rapidly reduced PEG and PVP chain mobility upon CO2 venting, delaying rearrangement for optimum
PEG–PVP H-bond interaction.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1002009 |
| Date | 04 February 2010 |
| Creators | Labuschagne, PW, John, MJ, Sadiku, RE |
| Publisher | Elsevier |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | © 2010 Elsevier B.V. |
| Relation | The Journal of Supercritical Fluids |
Page generated in 0.0023 seconds