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Polysulfone Comparisons — PSU vs PC, PEEK, Ultem

Polysulfone (PSU and PPSU) occupies a specific performance niche: it offers better heat and sterilization resistance than polycarbonate, broader food-contact compliance than Ultem PEI, and significantly lower cost than PEEK — while falling short of both Ultem and PEEK at extreme temperatures and of polycarbonate in optical clarity and impact resistance. This page indexes head-to-head comparisons for the three materials most commonly evaluated against polysulfone, with master comparison tables and selection guidance for each pairing.

At a glance:

  • PSU vs. Polycarbonate: PSU wins on temperature, sterilization, and hot-water resistance; PC wins on impact and optical clarity
  • PSU vs. PEEK: PEEK wins on temperature ceiling and chemical resistance; PSU wins on cost and FDA food-contact breadth
  • PPSU vs. Ultem: Ultem wins on continuous temperature and flammability; PPSU wins on sterilization cycles and food contact
  • All three comparisons turn on sterilization intensity, chemical exposure, and budget
  • Cross-material links below navigate to the full comparison pages

Polysulfone vs. Polycarbonate

Polycarbonate (Lexan, Makrolon) is the most common alternative evaluated against polysulfone. Both are transparent amorphous thermoplastics, but their performance diverges sharply in wet environments.

Key Differences

When to Choose Polycarbonate

Choose Lexan / polycarbonate when:

  • Optical clarity (water-clear transparency) is required
  • High impact resistance (machine guards, glazing) is the primary design driver
  • Service temperature stays below 200°F with no steam or hot-water exposure
  • Cost is the primary constraint and sterilization is not required

When to Choose Polysulfone

Choose PSU or PPSU when:

  • The part will be steam sterilized, autoclaved, or frequently exposed to hot water
  • Long-term contact with chlorinated municipal water is expected (plumbing applications)
  • FDA food-contact requirements must be met alongside elevated temperature service
  • Chemical resistance to disinfectants and cleaning agents is required

The full polycarbonate vs. polysulfone comparison covers a full property-by-property breakdown with application decision trees.

Polysulfone vs. PEEK

PEEK (polyetheretherketone) and polysulfone are both high-performance engineering thermoplastics, but PEEK represents the premium tier — higher on every property axis that matters for extreme environments, and priced accordingly.

Key Differences

When to Choose PEEK

Choose PEEK when:

  • Service temperature exceeds 350°F on a continuous basis
  • Aggressive chemical environments (concentrated acids, halogens) are present
  • The application requires the highest possible structural stiffness in a plastic
  • Unlimited autoclave cycling or dry heat sterilization is needed

When to Stay with Polysulfone

Choose PSU or PPSU instead of PEEK when:

  • Service temperature is below 300–350°F
  • Budget is a constraint — PEEK typically costs 4–6× more per pound than PSU
  • Transparency (amber) is needed for visual inspection of contents or fluid levels
  • FDA 21 CFR 177.1655 food contact compliance is needed — this specific listing applies directly to polysulfone
  • Steam sterilization cycles are under 1,000 and temperatures stay at 132°C or below

For applications like medical trays, food processing equipment, and hot-water plumbing where temperature demands don't require PEEK's 480°F ceiling, polysulfone provides equivalent functionality at a fraction of the cost.

Polysulfone vs. Ultem PEI

Ultem (polyetherimide, PEI) is the third material most commonly compared against polysulfone. Both are amorphous, amber-transparent, high-performance engineering thermoplastics with medical-grade credentials.

Key Differences

When to Choose Ultem PEI

Choose Ultem PEI when:

  • Continuous temperature exceeds 300°F (PSU's ceiling) and approaches 340°F
  • Inherent UL94 V-0 flammability rating is required (aerospace, electrical enclosures)
  • Maximum autoclave cycle durability is needed (Ultem reaches 2,000+ cycles vs. PPSU's 1,000+)
  • Structural stiffness (tensile strength 15,200 psi) is critical

When to Choose Polysulfone Over Ultem

Choose PSU or PPSU when:

  • Food contact with FDA 21 CFR 177.1655 compliance is required — Ultem does not carry this specific listing in standard grades
  • NSF 51 or NSF 61 certification is needed for food equipment or potable water
  • Cost must be minimized: PSU runs at roughly half the price of Ultem
  • PPSU's impact resistance (2.5 ft-lb/in) is preferable to Ultem's lower notched Izod (1.0 ft-lb/in)
  • Hot-water plumbing applications where NSF 61 is the governing requirement

Master Comparison: PSU / PPSU vs. All Three Alternatives

Navigation to Full Comparison Pages

Each pairing has a dedicated full-length comparison page covering detailed property tables, cost analysis, chemical resistance specifics, and application-level decision guidance:

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Frequently asked questions — Polysulfone FAQ