Add time:09/01/2019         Source:sciencedirect.com

A diamine-containing oxyethylene unit, 2,2-bis[4-[2-(4-aminophenoxy)ethoxy]phenyl]propane (BAEPP), was used as a monomer with various aromatic tetracarboxylic dianhydrides to synthesize polyimides via a conventional two-step procedure. The diamine was prepared through the nucleophilic displacement of [2,2-bis(4-β-hydroxyethoxy)phenyl]propane with p-chloronitrobenzene in the presence of K2CO3, followed by catalytic reduction. Depending on the dianhydrides used, the poly(amic acid)s obtained had inherent viscosities of 0.97–1.57 dL g−1. All the poly(amic acid)s could be cast from the DMAc solutions and thermally converted into transparent polyimide films. The polyimide films had a tensile strength range of 57–97 MPa, an elongation range at break of 3–7%. The polyimides derived from 4,4′-sulfonyldiphthalic anhydride and 4,4′-hexafluoro-isopropylidenediphathalic anhydride exhibited excellent solubility in organic solvents. These polyimides had glass transition temperatures between 252 and 314°C, and 10% mass loss temperatures were recorded in the range of 466–479°C in nitrogen. © 1997 Elsevier Science Ltd

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