Page 297 - Engineering Plastics Handbook

Chapter
12

Polyamide-imide (PAI)

Geoff Underwood
Research Scientist
Solvay Advanced Polymers LLC
Alpharetta, Georgia, USA

Introduction

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 maxi-
mum properties with a subsequent thermal cure process.

History
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

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