PPS GF40 vs PEEK: High-Temperature Plastic Comparison Guide

Where PPS GF40 Excels

Cost Efficiency

PPS GF40 costs approximately 75–85% less than PEEK while offering comparable temperature resistance and chemical stability. For structural applications under 200°C, PPS GF40 delivers the best performance-per-dollar of any high-temperature plastic.

Higher Stiffness

With a flexural modulus of 14 GPa, PPS GF40 is 4× stiffer than unfilled PEEK and 40% stiffer than PEEK GF30. For structural components requiring maximum rigidity, PPS GF40 is the superior choice.

Chemical Inertness

PPS has slightly better chemical resistance than PEEK, particularly against:

· Strong oxidizing acids (nitric, chromic)

· Hot aqueous solutions

· Amines at elevated temperature

Dimensional Stability

PPS GF40‘s extremely low water absorption (0.02% vs PEEK‘s 0.06%) and low CLTE give it the best dimensional stability of any engineering plastic in its temperature class.

Where PEEK Excels

Higher Temperature Capability

PEEK‘s 250°C continuous service temperature is 50°C higher than PPS‘s 200°C. For applications in the 200–250°C range (downhole tools, high-temp process equipment), PEEK is the only viable option.

FDA & Medical Compliance

PEEK meets FDA, USP Class VI, and ISO 10993 requirements. PPS is not FDA compliant and cannot be used for food or medical applications.

Wear & Bearing Performance

PEEK (especially bearing-grade PEEK with PTFE + graphite) has excellent wear and friction properties. PPS GF40 is not suitable for bearing applications due to its abrasive glass fibre surface.

Impact Toughness

PEEK‘s impact strength is comparable, and unfilled PEEK is tougher than PPS GF40. For applications subject to impact loads, PEEK is preferred.

Melt Processability

PEEK can be injection moulded, extruded, and 3D printed. PPS is also melt-processable but requires higher processing temperatures and more specialised equipment.

Application Selection Guide

For more comparisons, see our PEEK vs PEI guide and PEEK vs PTFE guide.