TABLE OF CONTENTS Polyamide-imides are thermoplastic amorphous polymers that possess exceptional mechanical, thermal, and chemical- and wear-resistant properties. They are inherently nonflammable, have outstanding electrical properties, and possess enormous temperature stability from cryogenic to 300 C. These properties place polyamide-imides at the top of the price and performance pyramid with polyketones and polyimides.
Polyamide-imides enjoy, as the name suggests, a positive synergy of properties from both polyamides and polyimides, such as flexibility, melt processability, elongation, dimensional stability, and toughness. Polyamide-imide polymers can be processed into a wide variety of forms, from injection- or compression-molded parts and ingots to coatings, films, fibers, and adhesives. Generally these articles reach their maximum properties with a subsequent thermal cure process.
With polyamide-imides sharing some of the best performance attributes of polyimides, they are considered a subset of this larger family. Polyimides were first developed in 1955 by Dupont [1] [3]. The class of polyamide-imides was subsequently commercially developed in the early 1960s [4] , [5] at Standard Oil of Indiana (Amoco) [*] and branded under the Torlon trademark.
A large driving market factor for these first polyamide-imides was the need for a high-temperature-capable insulation for magnet wire. In early 1961, Amoco Chemicals Company started a project to develop high-temperature wire enamel with investigations into aromatic polyester imides and polyamide-imides. From that development, the polyamide-imide wire enamel products were based on trimellitic anhydride chloride (TMAC) and 4,4 ?- methylenedianiline
