Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 6 of 6 for “"direct copolymerization"”.
-
Synthesis and Characterization of Sulfonated Poly (Arylene Ether Sulfone) Copolymers Via Direct Copolymerization: Candidates for Proton Exchange Membrane Fuel Cells
A designed series of directly copolymerized homo- and disulfonated copolymers containing controlled degrees of pendant sulfonic acid groups have been synthesized via nucleophilic step polymerization. Novel sulfonated poly (arylene ether sulfone) copolymers using 4,4'-bisphenol A, 4,4'-biphenol, …
-
High Temperature Polymers for Proton Exchange Membrane Fuel Cells
… for operating at higher temperatures in both direct methanol (DMFC) and H2/air PEM fuel cells. The need for thermally stable polymers immediately suggests the possibility of heterocyclic polymers bearing appropriate ion conducting sites. Accordingly, monomers and random disulfonated …
-
The Influence of Aromatic Disulfonated Random and Block Copolymers' Molecular Weight, Composition,and Microstructure on the Properties of Proton Exchange Membranes for Fuel Cells
… allowed for utiliziation of the crude SDCDPS directly in the copolymerization to save money, energy, and time. Three series of tert-butylphenyl terminated disulfonated poly(arylene ether sulfone) copolymers (BPSH35, 6FSH35, and 6FSH48) with controlled molecular weightsï¼ Mnï¼ , 20 to 50 …
-
Synthesis, crosslinking and characterization of disulfonated poly(arylene ether sulfone)s for application in reverse osmosis and proton exchange membranes
… BPS copolymers were synthesized via direct copolymerization of disulfonated activated aromatic halide monomers. The degree of disulfonation was controlled by varying the molar ratio of sulfonated to non-sulfonated dihalide monomers. The molecular weights of the copolymers were …
-
Synthesis, Characterization and Structure - Property Relationships of Post - sulfonated Poly(arylene ether sulfone) Membranes for Water Desalination
… polysulfone membranes were synthesized by direct copolymerization of pre-disulfonated comonomer and the sulfonate ions were placed on adjacent rings of bisphenol moiety. This study focuses on placing the sulfonate ions differently along the polysulfone backbone on isolated rings of …
-
Direct Polymerization Of Sulfonated Poly(arylene ether) Random Copolymers And Poly(imide)Sulfonated Poly(arylene ether) Segmented Copolymers: New Candidates For Proton Exchange Membrane Fuel Cell Material Systems
Commercially available 4,4′-dichlorodiphenylsulfone (DCDPS) was successfully disulfonated with fuming sulfuric acid to yield 3,3′-disodiumsulfonyl-4,4′-dichlorodiphenylsulfone (SDCDPS). Subsequently, DCDPS and SDCDPS were systematically reacted with 4,4′-biphenol under nucleophilic step …