Meaning
Semi-aromatic polyamides that contain benzene rings in their backbone structure offer high thermal stability and mechanical strength under demanding environment conditions. This class of performance resins, known as polyphthalamide, exhibits lower moisture absorption than aliphatic polyamides. It fills the performance gap between standard engineering plastics and high-temperature specialty polymers.
Material Property
The presence of aromatic rings in the polymer chain restricts molecular mobility, leading to a high glass transition temperature and excellent melt strength. It retains its stiffness at elevated temperatures, resisting creep even under continuous mechanical stress. Compounding with glass fibers or mineral fillers increases these properties further, making the resin a viable metal replacement material.
It also exhibits high chemical resistance against automotive fluids and solvents.
Moulding Guideline
Processing this resin requires high melt and mould temperatures to ensure proper crystallization and surface finish. If the mold temperature is too low, the part will have an amorphous skin, leading to post-moulding shrinkage and warpage as it crystallizes in use. Melt temperatures often exceed three hundred degrees Celsius, which requires heaters designed for high-temperature resins.
Adequate drying before moulding is necessary to prevent hydrolytic degradation during processing.
Industrial Use
Automotive engineers select this high-performance polymer for under-hood components like fuel lines, thermostat housings, and water pump impellers. It withstands prolonged exposure to hot coolant and engine oils without losing mechanical integrity. The material reduces part weight compared to traditional metals.
