Bruce McEuen is thanked for assisting in SMA amic acid preparations.
This resin contains amic acid functionality, groups that are possible to form only with anhydride-containing resins.
The formation of PAA and the completion of imide formation from amic acid
were confirmed by examining the FT-IR spectra; the spectra of PAA and the PI are shown in Fig.
Because of the randomness of the imidization reaction on the chain, at this stage there is no single specie of macromolecule, but rather several chains with varying contents of amic acid
To facilitate the characterization by spectroscopic analysis, we added an equimolar concentration of DPSD to the PAA, presuming that the silanediol functionality would react with the bifunctional amic acid
The resulting amic acid
groups were quantitatively imidized to the corresponding imide (PEMI) in the melt.
Since amic acid
formation is an equilibrium reaction, transamidation can occur when two PAAs or two precursors with very similar structure are combined in solution.
1] due to the amic acid
, together with the disappearance of weak and broad bands of carboxylic acid between 2650-2450 [cm.
The change in the rate constant on a logarithmic scale as a function of degree of imidization can be represented by two straight lines, indicating the existence of kinetically nonequivalent amic acid
Thermal imidization of the amic acid
precursor was achieved by first casting the poly(amic acid
) solution onto pyrex glass plates.
Designed as an alternative to polymers that are water-soluble only in high-pH, alkaline solutions, these SMA 1000MA amic acid
resins are said to eliminate the tarnish typical with bronze and copper dispersion while producing a pigment with "true metallic color.
Cuculo, JA, "Pad-Bake Reactions: Part I: A New Pad-Bake Reaction of Cellulose and Aqueous Solutions of Amic Acids