PPA
Polyphthalamide
Glass Transition (Tg)
120–130 °C
Melting Point (Tm)
290–330 °C
Density
1.17–1.20 g/cm³
CAS Number
—
Recycling Code
♺ 7
Category
High-Performance
Repeat Unit
–[NH–(CH₂)₆–NH–CO–C₆H₄–CO]ₙ–
The repeating unit is the smallest structural fragment whose repetition builds the whole chain. Subscripts show the relative share of each unit in copolymers.
Key Properties
Semi-aromatic polyamide; aromatic rings raise Tg and Tm, cut moisture uptake and improve chemical resistance versus PA66.
Applications
Coolant components, LED reflectors, high-temperature connectors.