Modified Poly(arylene ether sulfone) Compositions and their Segmented Block Copolymers
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In Chapter 2, hexafluoroisopropylidene bisphenol PAES (BAF PAES) segmented block copolymers containing various volume fraction of PDMS were synthesized. Analysis of the segmented block copolymer films by atomic force microscopy (AFM) and small angle x-ray scattering (SAXS) show the materials are microphase separated. Further analysis of the BAF PAES segmented block copolymers by transmission electron microscopy (TEM) show an increased morphological order with decreasing PDMS content, with lamellar morphologies formed at higher or near equal PAES and PDMS volume fractions. Comparatively, the morphological properties of the BAF PAES segmented block copolymers are considerably different from the isopropylidene bisphenol PAES (BA PAES) segmented block copolymer of similar PDMS volume percents.
In this document, segmented block copolymers prepared from BA PAES incorporating 4,4â -dihydroxyterphenyl (DHTP) and triptycene-1,4-hydroquinone (TPDH) co-monomers were characterized by proton nuclear magnetic resonance spectroscopy (1H NMR). Films of these materials, prepared from THF solution, were tested for thermal and tensile properties. These materials provide higher thermal stabilities over the BA PAES segmented block copolymers with thermal degradation ranging 380â 435 Â°C under nitrogen at 5%-wt. loss. Similarly, the PAES incorporating co-monomers gave higher Tg (200 Â°C) than the BA PAES (183 Â°C) synthesized in our labs. Previously synthesized BA PAES segmented block copolymers showed plastic to elastomeric tensile properties upon increasing addition of PDMS content. These new segmented block copolymers, incorporating co-monomers, provided comparable results with the reported BA PAES segmented block copolymers analogues.
The last research topic discussed in this dissertation covers the preparation of blends from 5% of segmented block copolymer and 95% of UdelÂ®, donated by Solvay Advanced Polymers. The preparation of blends from the segmented block copolymers containing random copolymers led to materials with higher moduli than UdelÂ® as observed by dynamic mechanical analysis (DMA). Tensile measurements performed by Instron also show the blends have high moduli, though no changes in the tensile elongation comparable to UdelÂ®.
- Doctoral Dissertations