Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Engineering
Development Of Miscible Blends Of Bisphenol A Polycarbonate And Lightly Sulfonated Polystyrene Ionomers From Intrapolymer Repulsive Interactions, Xinya Lu, Robert Weiss
Development Of Miscible Blends Of Bisphenol A Polycarbonate And Lightly Sulfonated Polystyrene Ionomers From Intrapolymer Repulsive Interactions, Xinya Lu, Robert Weiss
Robert Weiss
Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the phase behavior and interactions of blends of the free acid derivative and lithium and sodium salts of lightly sulfonated polystyrene (MSPS) with Bisphenol A polycarbonate (PC). The blends exhibited upper critical solution temperature (UCST) phase behavior and a miscibility window with respect to the sulfonation level. At a fixed blend composition, a minimum in the cloud point temperature occurs at the sulfonation level marking the middle of the miscibility window. The miscibility window depended on the sulfonate cation used. No interactions involving either the carbonate …
Characterization Of The Block Microstructure In Block Copolymer Ionomers Using Small Angle X-Ray Scattering, S. Mani, Robert Weiss, C. E. Williams, S. F. Hahn
Characterization Of The Block Microstructure In Block Copolymer Ionomers Using Small Angle X-Ray Scattering, S. Mani, Robert Weiss, C. E. Williams, S. F. Hahn
Robert Weiss
The block microstructure of a series of diblock copolymer ionomers was investigated using synchrotron small-angle x-ray scattering (SAXS). The base materials used were poly[styrene-b-(ethylene/propylene)] (SEP) diblock copolymers with a constant total molecular weight of ca. 50 kg/mol, but three different compositions : 20.3 wt%, 35.6 wt% and 50.4 wt% polystyrene (PS). The polystyrene microphase structures for these unmodified diblock copolymers were cylindrical, lamellar and lamellar, respectively. Ionomers were synthesized from the block copolymers by lightly sulfonating the PS blocks, followed by neutralization to the sodium and zinc salts. The introduction of ionic species into the PS blocks perturbed the block …