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{1308}
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ref: -0 tags: polyimide polyamide basic reduction salt surface modification date: 02-27-2015 19:45 gmt revision:0 [head]

Kinetics of Alkaline Hydrolysis of a Polyimide Surface

  • The alkaline hydrolysis of a polyimide (PMDA-ODA) surface was studied as a function of time, temperature and hydroxide ion concentration.
  • Quantification of the number of carboxylic acid groups formed on the modified polyimide surface was accomplished by analysis of data from contact angle titration experiments.
  • Using a large excess of base, pseudo-first-order kinetics were found, yielding kobs ≈ 0.1−0.9 min-1 for conversion of polyimide to poly(amic acid) depending on [OH-].
  • From the dependence of kobs on [OH-], a rate equation is proposed.
  • Conversion of the polyimide surface to one of poly(amic acid) was found to reach a limiting value with a formation constant, K, in the range 2−10 L·mol-1.

{1280}
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ref: -0 tags: kevlar polyamide orientation thin-films date: 04-07-2014 19:08 gmt revision:1 [0] [head]

Preparation of uniaxially oriented polyamide films by vacuum deposition polymerization

  • Jiro Sakata, Midori Mochizuki
  • Grew polyamide (PPTA, kevlar) films using VDP (vacuum deposition polymerization).
    • Two precursors were heated in a vacuum to yield a stoichiometric polymer.
  • Polymer chains were oriented with rubbing with different polymers, e.g. cotton (!)