Publication details
Poly(imide-amide)-poly(ethylene glycol) hybrid networks: nanostructure, molecular dynamics and membrane properties
| Authors | |
|---|---|
| Year of publication | 2007 |
| Type | Article in Periodical |
| Magazine / Source | Polymer Bulletin |
| MU Faculty or unit | |
| Citation | |
| Field | Macromolecular chemistry |
| Keywords | polyimides;nanostructure;molecular dynamics |
| Description | Nanometer-scale structure, mol. dynamics (at 100-580 K) and membrane properties were studied in two series of poly(imide-amide) (PIA)-poly(ethylene glycol) (PEG) hybrid networks with regularly varied compn. and different lengths of PEG crosslinks (Mn= 1000 or 3400). Combined WAXD/SAXS/polarized microscopy/DSC/DRS/TSDC/creep rate spectroscopy (CRS) anal. of these hybrids was performed. Depending on their compn., semicryst. or mesomorphous, or amorphous state, and nanostructural heterogeneity were obsd. for these networks. They could be subdivided into (a) the PIA-rich hybrids with spatially isolated PEG domains, "suppressed" dynamics in the PEG glass transition, and PIA domains with Tg=520-570 K (group 1), and (b) the other hybrids with a continuous PEG phase and low-temp. glass transition only (group 2). Heterogeneity in segmental dynamics was revealed by CRS over the temp. range from TgPEG to TgPIA. In the second group of hybrids, the permeability coeffs. were higher, by 2 or 3 orders of magnitude, for org. vapors than those for air gases. |