Home » News » What Is The Different between PPS And PPSU

What Is The Different between PPS And PPSU

Views: 0 Author: Site Editor Publish Time: 2026-10-21 Origin: Site

Inquire

Although the names of PPS (polyphenylene sulfide) and PPSU (polyphenylene sulfone) are similar, their applications are quite different. PPS material is a semi-crystalline, highly rigid and corrosion-resistant plastic, while PPSU material is a non-crystalline, highly resilient plastic without bisphenol A (BPA). We usually choose PPS material because it has higher mechanical strength, high temperature resistance and corrosion resistance; while in food and medical applications, or in situations requiring high impact resistance, PPSU material can be selected. The semi-crystalline PPS material still provides rigidity when it reaches Tg 90°C. The Tg temperature of non-crystalline PPSU is as high as 220°C, but the modulus of the material will significantly decrease when the temperature reaches Tg.

1. Material Essence and Structural Differences

Item	PPS	PPSU
Chemical Structure	Benzene ring + thioether bond -[C6H4-S]-n	Biphenyl + sulfone group + ether bond
Crystallinity	Semi-crystalline (crystallinity 35–50%)	Amorphous
Appearance	Opaque (off-white/gray/black)	Amber, translucent
Inherent Flame Retardancy	UL94 V-0	UL94 V-0
Water Absorption	Extremely low ~0.02% (ASTM D570)	Low ~0.37%

Semi-crystallinity gives PPS high rigidity, dimensional stability, and solvent resistance. Being amorphous gives PPSU high toughness, transparency, and hydrolysis stability under steam.

Explore PPS Material | View PPSU Material

2. Mechanical Properties

Unfilled Resin Baseline

Metric	PPS (Unfilled)	PPSU (Unfilled)
Tensile Strength	65–90 MPa (ASTM D638)	70–80 MPa (ASTM D638)
Elongation at Break	1–2% (brittle)	25–50% (tough)
Flexural Modulus	3.5–4.5 GPa (ISO 178)	2.3–2.5 GPa (ISO 178)
Notched Izod Impact	20–50 J/m (low)	500–690 J/m (high)
Rockwell Hardness R	~120	~130

Data sources: Public domain resin datasheets (e.g., Ryton® PPS, Solvay PPSU). Values vary by grade; confirm with specific TDS.

At neat resin level, tensile strengths are comparable. PPS modulus is ~50% higher, but impact strength is only 1/10 to 1/20 of PPSU's.

After Glass Fiber Reinforcement (Industrial Reality)

PPS engineering parts are almost always reinforced. PPSU is typically used neat or with 30% GF.

Grade	Tensile Strength	Flexural Modulus	HDT (1.8 MPa)	Notched Impact
40% GF-PPS (e.g., Ryton R-4)	150–190 MPa	12–15 GPa	260–280°C	50–80 J/m
30% GF-PPSU (e.g., RG-5030)	~120–125 MPa	8.5–9 GPa	215–225°C	75–80 J/m
Neat PPSU	70–80 MPa	2.3–2.5 GPa	196–207°C	500–690 J/m

Note: Unreinforced PPS HDT at 1.8 MPa drops to ~110°C because the amorphous phase cannot sustain load above Tg (~85°C). Load-bearing PPS parts must be reinforced.

Mechanical Selection Logic

High rigidity, creep resistance, long-term static load → PPS+GF (GF40)
Drop resistance, impact resistance, anti-cracking, thin-wall → Neat PPSU
Unreinforced PPS is notch-sensitive; weld line strength is only 50–70% of bulk
Neat PPSU will creep under sustained stress; for heavy-load parts, use GF30

3. Thermal Performance

Metric	PPS	PPSU
Glass Transition Temp (Tg)	~85–90°C	~220°C
Melting Point	280–290°C	None (amorphous)
HDT (1.8 MPa, reinforced)	260–280°C (GF40)	215–225°C (GF30)
HDT (1.8 MPa, neat)	~110°C	196–207°C
Continuous Service Temp	200–240°C*	~180°C*
Coefficient of Thermal Expansion	3–5 × 10⁻⁵/°C (reinforced)	Medium

*Continuous service temperature depends on load, media, and specific grade. Always verify with supplier TDS.

Key insight: PPS has a low Tg (~85°C) but its semi-crystalline structure maintains shape well above Tg—up to its melting point (~280°C). PPSU's high Tg (~220°C) means it retains rigidity to higher temperatures, but as an amorphous polymer, modulus drops rapidly once Tg is exceeded.

4. Electrical Properties

Metric	PPS	PPSU
Volume Resistivity	Excellent insulator; typical range 10¹⁴–10¹⁶ Ω·m depending on grade	Excellent insulator; typical range 10¹⁴–10¹⁶ Ω·m depending on grade
Dielectric Strength	~18 kV/mm (ASTM D149)	~15–26 kV/mm (ASTM D149)
Dielectric Constant	Lower, stable across frequency	Moderate; higher than PPS
Arc Resistance	High in mineral-filled grades	Good; not primary marketing claim

Note: Resistivity values are grade-dependent. Confirm exact figures against the specific resin datasheet. Do not use generic values for design validation.

Selection guidance:

Connectors, bobbins, SMT high-temp insulation → PPS (especially GF/mineral-filled)
Humid-heat environments → PPSU retains insulation better than PPS
High-frequency, low dielectric loss → PPS is more stable

5. Chemical Resistance and Steam Sterilization

PPS and PPSU offer different chemical and hydrothermal resistance profiles. PPS is often considered for applications requiring resistance to many oils, fuels, solvents and corrosive media, while PPSU is widely used in components exposed to repeated hot-water and steam sterilization.

Environment	Preferred Material	Reason
Organic solvents, fuels, oils, acids/bases (high-temp dry)	PPS	Semi-crystalline structure is highly resistant
Hot water, 134°C steam, repeated sterilization, alkaline cleaning	PPSU	Excellent hydrolytic stability; widely used for reusable medical devices
Long-term boiling water / high-pressure steam	Avoid PPS	Risk of hydrolysis and degradation
Chlorinated solvents, strong polar organics	Use caution with PPSU	May cause stress cracking

Important: Actual compatibility depends on the polymer grade, chemical concentration, temperature, exposure time and mechanical stress. Before replacing one material with the other, verify the supplier's chemical compatibility data and test the material under representative operating conditions. Steam sterilization cycle counts (e.g., "1000+ cycles") vary by part geometry, stress level, and autoclave parameters—confirm with grade-specific test reports.

6. Modification Types

PPS Modification Systems

Glass Fiber Reinforced (GF30–40): Mainstream structural parts
GF + Mineral Filling: Low shrinkage, dimensional stability, arc resistance
Wear-resistant/Lubricated (PTFE/Graphite): Valve seats, gears
Elastomer Toughened: Improved notched impact at modest modulus cost
Carbon Fiber Reinforced (CF30): Higher modulus + conductivity
Conductive/Antistatic (ESD): Chemical equipment, electronic components

PPSU Modification Systems

Neat Resin General Purpose (e.g., R-5000): Medical, food contact, infant care
Glass Fiber Reinforced GF30 (e.g., RG-5030): Increased rigidity and creep resistance
Dental Hydrolysis-Resistant (e.g., DuraDEX D series): Long-term humid-heat oral devices
Acudel Copolymer: Low warpage, low internal stress for large fluid valve bodies
Aviation Low-Smoke FR (e.g., R7000 series): Cabin interiors
PPSU/PTFE Blends: Reduced friction for sliding parts

7. Processing Differences

PPS Processing

The parameters below are general starting points, not universal settings for every PPS grade. Recommended drying conditions, melt temperature, mold temperature and injection pressure vary with the resin grade, reinforcement level, part geometry and molding equipment. Always follow the grade-specific technical data sheet and validate settings through molding trials.

Parameter	Typical Range
Drying	120°C / 2–4 h (recommended, not always mandatory)
Barrel Temperature	~300–330°C (slightly higher for reinforced grades)
Mold Temperature	Medium-low acceptable; 120°C+ for reinforced parts to reduce warpage
Shrinkage (flow)	0.2–0.4% (crystalline; higher in transverse direction)
Annealing	150°C / 2–4 h to relieve internal stress

Pros: Good flow, short cycle times, lower cost. Cons: Uneven cooling causes warpage; mold design must account for anisotropic shrinkage.

PPSU Processing

The parameters below are general starting points, not universal settings for every PPSU grade. Always follow grade-specific TDS and conduct molding trials.

Parameter	Typical Range
Drying	Mandatory: 120–150°C / 4 h+, moisture < 0.02%
Barrel Temperature	330–380°C (degradation risk above 400°C)
Mold Temperature	Must be high: 130–165°C (low mold temp = high stress/cracking)
Injection Pressure	100–160 MPa, medium-high speed
Holding Pressure	40–60% (avoid over-packing)
Annealing	160°C for thick-wall/precision parts

Pros: Excellent toughness, suitable for thin-wall complex parts. Cons: Narrow processing window, moisture sensitivity, slower cycles.

Processing difficulty: PPSU > PPS. PPSU demands tighter control of mold temperature, drying, and residence time.

8. Applications and Selection Examples

PPS Primary Applications

Automotive engine peripherals: water pump impellers, thermostat valves, sensor housings
Electronics & Electrical: connectors, bobbins, SMT components, insulating skeletons
Chemical fluids: valve bodies, pump parts, linings, pipe fittings
Battery/New Energy: battery tray structural parts, electronic control insulation

→ Explore PPS Grades & Products

PPSU Primary Applications

Medical devices: surgical instrument handles, sterilization trays, dental equipment
Food & Infant: baby bottles, breast pumps, coffee machine tanks, water purification valves
Aerospace interiors: cabin parts, cart structures (low smoke/toxicity)
Hot water systems: high-temp faucets, mixing valves, sterilization chambers

→ View PPSU Material Options

Selection Decision Matrix

Operating Condition	Recommended Material
High-temp dry heat + oil/solvent + high rigidity	PPS (GF40)
Repeated steam sterilization + impact resistance + transparency	Neat PPSU
Rigidity + steam resistance combined	PPSU GF30 (accept reduced impact)
Drop/impact loads in PPS application	Toughened PPS or switch to PPSU
Long-term boiling water / alkaline washing	Do not use PPS
Chlorinated solvents / strong organics	Use caution with PPSU
Budget-sensitive functional parts	PPS
Medical/food with high unit-price tolerance	PPSU

9. Frequently Asked Questions

Q: Can PPSU really survive 1000+ steam sterilization cycles?

A: PPSU is widely documented for repeated autoclave resistance, but exact cycle counts depend on steam temperature, pressure, part thickness, and stress level. Verify with the specific grade's test data before specifying.

Q: Is PPS always brittle?

A: Unreinforced PPS is notch-sensitive and relatively brittle. Glass fiber reinforcement dramatically improves strength and stiffness but does not fully eliminate impact sensitivity. For high-impact applications, consider toughened PPS grades or PPSU.

Q: Which material is better for electrical insulation in humid environments?

A: PPSU generally retains insulation properties better under high humidity due to lower moisture absorption impact on electricals. However, PPS with proper reinforcement offers superior arc resistance and dimensional stability.

Q: Can I replace metal with PPS or PPSU?

A: Both are used as metal replacements. PPS is preferred where chemical resistance and rigidity are critical (e.g., pump housings). PPSU is chosen where impact resistance and steam sterilization are required (e.g., surgical instruments).

Technical Data Sources & Disclaimer

Material property values in this article are compiled from publicly available technical datasheets (including Ryton® PPS, Solvay PPSU, and other industry-standard grades) and PRES internal testing where noted. Specific values depend on:

Resin grade and manufacturer
Reinforcement type and loading
Test method and specimen geometry
Environmental conditions

For design-critical applications, always request the current TDS and MSDS from your material supplier and conduct application-specific testing. PRES provides material selection support—contact our technical team for grade recommendations tailored to your operating conditions.

Article prepared by PRES Technical Engineering Team. Last updated: [2026-10-24-18:29:38]. For the latest data, consult individual product pages: PPS Material | PPSU Material

Rio Liang | High-Performance Plastics Expert

Email: rioplastic@foxmail.com TEL/Whatsapp/Wechat: 008613421811533

20+ Years specializing in PEEK, PPSU, PES, PPS & PEI materil modification. Expert in resolving material properties and injection molding solutions. Open to technical discussions.

Contact Us

Send E-mail