2. Properties

Because of their high crystallinity, due to the unbranched structure of their macromolecular chains, POMs are distinguished by a happy combination of different properties, in particular :

• high mechanical properties at low (–40 ˚C) and high (up to 105 ˚C) temperatures;

• excellent elastic memory (spring effect);

• low coefficient of friction and high abrasion resistance (hence the name self-lubricating polymers);

• excellent resistance to solvents and bases for copolymers;

• low gas permeability;

• good dielectric properties.

The properties of POMs depend in part on their degree of crystallinity and their molar mass (table