Polyimides condensation

Nonthermoprocessible Condensation Polyimides. These are obtained from condensation of aromatic dianhydrides with aromatic diamines. They are linear noncross-linked resins but their rigid chain stmcture and strongly hydrogen-bonded character leads to systems which do not melt or soften before decomposition. 

Thermoplastic Condensation Polyimides. These include General Electric s Ultem Resin and Amoco s Todon polyamideimide although the latter is no longer offered as injection moldable pellets, but as compression moldable powder and in solution. Another resin, P-84, originally developed by Upjohn but now made by Lenzing (Austria), is based on benzoquinone dianhydride and aromatic isocyanates. 

Volksem W. Condensation Polyimides Synthesis, Solution Behavior, and Imidization Characteristics. VoL 117, pp, 111-164. 

Condensation polyimides or SP-polyimides from the solvent-phase reaction of an aromatic tetra-acid with a diamine. Despite the thermoplastic form they are infusible and generally insoluble. Consequently, the producer can only mould this type. It is particularly convenient for the manufacture of thin parts and films, coatings... 

For condensable polyimides, the current processing methods are applicable only by the polyimide producer that sells finished parts, blanks, rods, sheets, films. .. Machining is an important method for processing the polyimide blanks. 

Characterization of Cobalt (II) Chloride-Modified Condensation Polyimide Films... 

Cobalt(II) chloride was dissolved in poly(amide acid)/ N,N-dimethylacetamide solutions. Solvent cast films were prepared and subsequently dried and cured in static air, forced air or inert gas ovens with controlled humidity. The resulting structures contain a near surface gradient of cobalt oxide and also residual cobalt(II) chloride dispersed throughout the bul)c of the film. Two properties of these films, surface resistivity and bullc thermal stability, are substantially reduced compared with the nonmodified condensation polyimide films. In an attempt to recover the high thermal stability characteristic of polyimide films but retain the decreased surface resistivity solvent extraction of the thermally imidized films has been pursued. 

Much of the recent wor)c pertaining to metal ion modified polyimides has been aimed at increasing the surface electrical conductivity of condensation polyimides (6,7,8). This has been accomplished to a significant extent (surface resistivity reduced up to 11 orders of magnitude (8,9)) but in most systems the bul)c... 

Table II. Electrical Properties of Dry Air Cured Cobalt Chloride Modified Condensation Polyimide Filins...

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