PPA resin semi-aromatic polyamide. Both semi-crystalline and non-crystalline, the glass transition temperature is around 255 °F. Amorphous PPA is mainly used in applications where barrier properties are required; semi-crystalline PPA resins are mainly used for injection molding, and are also used in other semi-crystalline PPA resins in other melt processing processes, unless otherwise noted. The semi-crystalline PPA has a melting point of about 590 °F and is supplied in the form of an opaque rectangular section. PPA resins are stronger and harder than fatty polyamides such as nylon 6,66; they are less sensitive to moisture; have better thermal properties; and are much better in creep, fatigue and chemical resistance.
