PPS (40% Glass-Filled) vs PEEK
PPS (40% glass-filled) and PEEK are both high-performance, chemical-resistant engineering plastics for hot, aggressive service. The glass-filled PPS here is very stiff and dimensionally stable for pumps and hot-fluid parts at lower cost. PEEK is the higher-tier polymer — higher continuous-temperature capability (~250°C nominal), greater toughness, and the choice when PPS runs out of thermal or mechanical headroom.
The verdict
Choose PPS 40% glass-filled for chemical pumps, manifolds and hot-fluid components where high stiffness and chemical resistance are needed at lower cost (3.5 vs 5). Choose PEEK when service exceeds PPS's ~220°C, when toughness and ductility matter, or for medical-grade and the most demanding chemical/wear parts at ~250°C nominal.
Side-by-side data
| Property | PPS (40% Glass-Filled) | PEEK |
|---|---|---|
| Category | Engineering Plastic | Engineering Plastic |
| Density (g/cm³) | 1.66 | 1.32 |
| Tensile strength (MPa) | 180 | 100 |
| Yield strength (MPa) | 150 | 97 |
| Elongation (%) | 1.5 | 45 |
| Hardness | R123 | R126 |
| Max service temp (°C) | 220 | 250 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 0.3 | 0.25 |
| Typically used for | Chemical pumps & hot fluid components | High-temp, chemical & medical-grade parts |
Which should you choose?
Choose PPS 40% Glass-Filled when…
- You need very high stiffness and dimensional stability — ~180 MPa tensile nominal from the glass fill
- Parts are chemical pumps, manifolds or hot-fluid components up to ~220°C
- Top chemical resistance (corrosion 5) against aggressive fluids is required
- Lower cost than PEEK (3.5 vs 5) matters at volume
- The part is injection-molded to a stiff, stable net shape
- Brittleness from glass fill (~1.5% elongation) is acceptable for a rigid component
Choose PEEK when…
- Continuous service runs hot — PEEK is rated ~250°C nominal versus PPS-GF's ~220°C
- You need toughness and ductility (~45% elongation) rather than glass-filled brittleness
- Medical-grade, implantable or sterilizable parts are required
- The part sees wear, fatigue or impact alongside heat and chemicals
- Top-tier chemical resistance (corrosion 5) plus mechanical robustness is needed
- Higher cost (5) is justified by the performance and qualification
Key differences that matter
- PEEK has higher continuous-temperature capability (~250°C nominal) than the PPS-GF grade (~220°C).
- The 40% glass fill makes PPS very stiff (~180 MPa tensile) but brittle (~1.5% elongation); unfilled PEEK is tougher at ~100 MPa tensile and ~45% elongation.
- Both rate top chemical resistance (corrosion 5) and suit aggressive-fluid service.
- PPS-GF costs less (3.5 vs 5), making it the value choice when its temperature and toughness suffice.
- PEEK is the medical/implant and high-wear standard; PPS-GF is a workhorse for chemical pumps and hot manifolds.
- Compare like with like: a glass-filled PEEK would beat both on stiffness — the dataset's PEEK is unfilled, so it trades stiffness for toughness.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is PEEK always better than PPS?
No — PEEK has higher temperature and toughness, but the glass-filled PPS here is actually stiffer (~180 vs 100 MPa tensile nominal) and costs far less (3.5 vs 5). If your part fits PPS's ~220°C limit and wants rigidity and chemical resistance, PPS-GF is the smarter, cheaper choice. PEEK earns its premium only when you need its heat or toughness.
Why is the glass-filled PPS so brittle?
The 40% glass fill that gives PPS its high stiffness and dimensional stability also drops elongation to about 1.5%, so the material is rigid but low-strain — it resists bending but won't absorb much impact before cracking. Unfilled PEEK, by contrast, stays ductile (~45% elongation), which is why it's preferred where toughness matters.
Which should I pick for a chemical pump?
Either resists aggressive chemistry (both rate corrosion 5). For standard hot-fluid pumps and manifolds up to ~220°C, PPS 40% glass-filled gives the stiffness and stability you want at lower cost. Step up to PEEK when temperatures exceed PPS's range or when the part also faces wear, fatigue or impact loading.
Are both suitable for medical parts?
PEEK is the established medical and implantable-grade polymer, available in biocompatible grades and widely sterilized. The 40% glass-filled PPS here is an industrial chemical/thermal material, not positioned for implants. For medical or surgical components, PEEK is the appropriate choice of the two.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.