PVDF (Kynar) vs PPS (40% Glass-Filled)
PVDF (Kynar) and 40% glass-filled PPS are both fluoropolymer-class engineering plastics built for aggressive chemicals and elevated temperatures, but they solve different problems. PVDF is a tough, weldable, ultra-pure fluoropolymer favored in semiconductor and high-purity fluid handling. Glass-filled PPS is a stiff, dimensionally stable, higher-temperature thermoplastic that costs less per part for structural pump and hot-fluid components.
The verdict
Choose PVDF (Kynar) for high-purity and ultrapure fluid handling, weldable piping, and applications needing toughness and chemical purity. Choose 40% glass-filled PPS when you need maximum stiffness, dimensional stability, and continuous service near 220 C in structural pump and hot-fluid parts at lower cost. Both rate top-tier (5/5) for corrosion resistance.
Side-by-side data
| Property | PVDF (Kynar) | PPS (40% Glass-Filled) |
|---|---|---|
| Category | Engineering Plastic | Engineering Plastic |
| Density (g/cm³) | 1.78 | 1.66 |
| Tensile strength (MPa) | 50 | 180 |
| Yield strength (MPa) | 50 | 150 |
| Elongation (%) | 50 | 1.5 |
| Hardness | R110 | R123 |
| Max service temp (°C) | 150 | 220 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 0.19 | 0.3 |
| Typically used for | Ultrapure chemical piping & valves | Chemical pumps & hot fluid components |
Which should you choose?
Choose PVDF (Kynar) when…
- You need ultrapure or high-purity fluid handling (semiconductor, pharma) where leachables and contamination matter
- Parts must be welded — PVDF is readily heat- and fusion-welded for piping and valve assemblies
- Toughness and impact resistance matter; unfilled PVDF has roughly 50% elongation versus PPS-GF's ~1.5%
- You want easier machining (4.0/5 vs ~2.5/5 for abrasive glass-filled PPS)
- Service temperature stays at or below ~150 C max in this dataset
- Excellent resistance to halogens, strong acids, and UV in piping and valve bodies
Choose 40% Glass-Filled PPS when…
- You need high stiffness and structural rigidity — tensile ~180 MPa vs PVDF's ~50 MPa (nominal, glass-fiber reinforced)
- Continuous service runs hotter, up to ~220 C versus PVDF's ~150 C
- Dimensional stability and low creep under load are critical for pump housings and impellers
- You want strong chemical resistance at lower material cost (both ~3.5/5 cost here, but PPS-GF buys far more stiffness per dollar)
- Low water absorption and tight tolerances must hold over temperature
- The part is structural, not a purity-critical wetted surface
Key differences that matter
- Both rate 5/5 for corrosion resistance and excel against aggressive chemicals, acids, and solvents
- PPS-GF is far stiffer (~180 MPa tensile vs ~50 MPa) but the glass fill makes it brittle, with only ~1.5% elongation
- PVDF tolerates much higher strain (~50% elongation), giving it toughness PPS-GF lacks
- PPS-GF holds a meaningful temperature edge: ~220 C max vs PVDF's ~150 C in this dataset
- PVDF is weldable and machines easily (4.0/5); glass-filled PPS is abrasive and harder to machine (2.5/5)
- PVDF is the high-purity choice — semiconductor and pharma wetted parts prize its low extractables
- Costs are similar here (~3.5/5 each), but PPS-GF delivers more structural performance per dollar
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Open the Material SelectorGet a Quote →Frequently asked questions
Which is more chemically resistant, PVDF or PPS?
Both rate 5/5 for corrosion resistance and handle most acids, bases, and solvents. PVDF excels with halogens and strong oxidizers and is the high-purity standard, while PPS resists a very broad chemical range too. The deciding factor is usually purity and temperature, not raw chemical resistance — verify against your specific media.
Why is glass-filled PPS so much stronger than PVDF?
The 40% glass fiber reinforcement is the reason. It lifts tensile strength to roughly 180 MPa and dramatically raises stiffness versus unfilled PVDF at ~50 MPa. The tradeoff is brittleness — PPS-GF elongates only ~1.5% before failure, while PVDF tolerates around 50% strain and absorbs impact far better.
Can both materials be welded?
PVDF welds readily by heat fusion, butt fusion, and electrofusion, which is a major reason it dominates chemical and ultrapure piping. Glass-filled PPS is generally not fusion-welded for structural joints; it is injection molded or machined and joined mechanically. If your design relies on welded thermoplastic piping, PVDF is the practical choice.
Which handles higher temperatures?
PPS-GF. This dataset lists its max service near 220 C versus PVDF at about 150 C. For hot process fluids, pump internals, and under-hood components, PPS-GF holds dimensional stability and strength at temperatures where PVDF softens. For service at or below 150 C, PVDF remains a strong option.
Which should I pick for semiconductor or pharma fluid handling?
PVDF (Kynar). Its high-purity grades have very low extractables and excellent compatibility with ultrapure water and aggressive process chemistry, plus weldable piping for clean, leak-tight systems. PPS-GF is better reserved for structural hot-fluid and pump parts where purity is not the governing requirement.
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.