The GreenThinking® PF series is a family of activated, nano sized composite mineral fillers characterized by high whiteness, nano scale particle size, high reinforcing efficiency, and environmentally friendly, odor free properties. As an eco friendly non toxic rubber reinforcing agent, the PF series serves as both high gas barrier rubber compounding fillers and low odor rubber fillers for automotive interior applications. Among them, PF87 — a dehydroxylated activated nano reinforcing agent — demonstrates outstanding performance in reinforcement, gas barrier properties, processability, and resistance to surface iridescence (“oil slick” effect). This report provides an overview of the PF series and presents validated application data for PF87 as a partial replacement for carbon black N660 in tire inner liners, answering the question of how to improve gas barrier properties of tire inner liner through functional filler technology. The PF87 grade also acts as a nano reinforcing filler for tire inner liner, offering formulators an objective reference for material selection.
1. Product Overview and Classification
The GreenThinking® PF series is manufactured from selected high whiteness natural composite minerals through fine processing and dehydroxylation activation. The particle size distribution is concentrated in the nano range (D50 100–200 nm; PF87 typically approx. 150 nm), with high chemical purity and controlled batch to batch consistency. These products are designed as activated nano composite filler for polar and nonpolar rubber, ensuring broad compatibility.
Main grades: PF81, PF82, PF87, PF88, PF90, PF91, PF93, PF95 (backup), etc.
Typical characteristics of PF87:
- Appearance: high whiteness powder, suitable for light colored or colored rubber products
- Particle size: D50 ≈ 100–200 nm (measured approx. 153 nm)
- Morphology: lamellar structure, high porosity
- Environmental compliance: odor free, meets REACH, RoHS, etc.
- Surface treatment: dehydroxylated activation for improved compatibility with rubber matrices
2. Reinforcing Performance and Mechanism of Action
2.1 Reinforcing Efficiency
The reinforcing effect of the PF series approaches that of carbon black N550. For PF87, at equal loading, tensile strength, tear strength, and abrasion resistance are significantly superior to conventional mineral fillers. The PF series can function as a functional mineral filler to replace carbon black N550 in many rubber formulations, including those requiring high reinforcement without the black color.
Key data (internal testing, EPDM sulfur cure):
- Tear strength: up to 15.87 kN/m (comparable to Germany Hoffmann VM52)
- Reinforcement level: approaching N550
2.2 Mechanism of Action
- Nano size effect: D50 between 100–200 nm provides high specific surface area, creating strong physical bonding with rubber chains.
- Dehydroxylated activated surface: Reduces surface polarity, improving dispersion in non polar rubbers (NR, BR, SBR, EPDM, IIR).
- Lamellar structure and high porosity: Extends the gas diffusion path, significantly enhancing gas barrier properties; also improves reinforcement and reduces compression set. This directly addresses how to improve gas barrier properties of tire inner liner without sacrificing mechanical performance.
- Reduces “oil slick” / iridescence effect: Unlike carbon black, PF87 contains no extractable hydrocarbons that migrate to the surface, effectively preventing surface iridescence in rubber products and answering the question of how to solve oil slick defect on rubber surface.
3. General Performance Comparison and Selection Matrix
| Grade | Reinforcement | Compression Set | Cost | Recommended Applications |
| PF87 | High | Medium | Medium | High gas barrier & reinforcement requirements; also serves as a high whiteness lamellar structure mineral filler for EPDM seals when whiteness and sealing performance are critical. |
| PF91 | Medium high | Medium high | Lower | Aging resistant parts, cost sensitive |
| PF93 | Medium | High | Low | Low compression set sealing parts |
| PF81 | Medium | Medium low | Lower | High loading, low cost general parts |
Polar rubbers (NBR, HNBR, CR, ACM): PF87, PF93 (sulfur cure); PF93, PF91 (peroxide cure).
Non polar rubbers (NR, SBR, BR, EPDM, IIR): PF87, PF91 (reinforcement priority); PF93, PF81 (cost priority). As an activated nano composite filler for polar and nonpolar rubber, PF87 exhibits excellent compatibility across both categories.
4. Processing Advantages
| Processing Property | PF Series (especially PF87) Performance |
| Dispersion | Activated surface ensures good dispersion in internal mixers; smooth extruded surface |
| Scorch safety | Extended scorch time improves process safety |
| Cure rate | Slightly longer optimum cure time (Tc90) – controllable |
| Loading capacity | Lamellar structure allows high loading without significant property loss |
| Odor | Odor free – suitable for automotive interior or enclosed applications. This makes PF87 one of the leading odor free functional nano reinforcing fillers for automotive rubber. |
| Color | High whiteness; reduces “oil slick” / iridescence caused by carbon black, thus preventing surface iridescence in rubber products. |
Additionally, PF87 and related grades are excellent low odor rubber fillers for automotive interior components such as seals, hoses, and trim, where volatile emissions must be minimized.
5. Application Validation: PF87 in Tire Inner Liners
Tire inner liners require high gas barrier properties, good processability, flex fatigue resistance, and adhesion to the carcass. Conventional formulations use carbon black N660 as the primary reinforcing filler. PF87 serves as a partial replacement for carbon black N660, demonstrating that a nano reinforcing filler for tire inner liner can improve performance while reducing carbon black usage. The following data are from comparative testing where PF87 partially replaced N660 in an inner liner compound (SaneZen internal validation).
5.1 Processability
| Parameter | Control (N660) | PF87 containing | Trend |
| Mooney viscosity ML(1+4)@100°C | Baseline | Lower | Improved processability |
| Scorch time (t5 @130°C) | Baseline | Comparable | No safety loss |
| Torque (MH) | Baseline | Slightly lower | — |
| Optimum cure time (Tc90) | Baseline | Slightly delayed | Adjust cure system if needed |
Conclusion: PF87 reduces compound viscosity, improving extrusion and calendering efficiency, without sacrificing scorch safety. The slight delay in cure rate can be compensated by minor adjustments to the accelerator package or cure temperature.
5.2 Physical Properties and Gas Barrier
| Property | vs. N660 Baseline | Remarks |
| Gas barrier (air retention) | Improved | Lamellar structure extends diffusion path – directly answering how to improve gas barrier properties of tire inner liner. |
| Flex crack resistance (De Mattia) | Equivalent | No reduction in fatigue life |
| Tensile strength / modulus | Equivalent | Reinforcement level maintained |
| Tear strength | Equivalent or slightly better |
Conclusion: The lamellar morphology and nano size of PF87 significantly improve the gas barrier of the inner liner compound, which helps maintain tire pressure and indirectly reduces rolling resistance. As one of the high gas barrier rubber compounding fillers available, PF87 enables thinner inner liners or higher inflation pressure retention.
5.3 Additional Benefits
- Preventing surface iridescence in rubber products: Carbon black may contain extractable aromatic hydrocarbons that migrate to the surface during vulcanization or service, causing an “oil slick” defect. PF87 is an inorganic mineral with no such migration – particularly valuable for white sidewalls or light colored inner liners. This directly addresses how to solve oil slick defect on rubber surface.
- Lower odor: Inner liner compounds containing PF87 exhibit lower odor, making them low odor rubber fillers for automotive interior even for tire applications where interior air quality is a concern.
- Eco friendly non toxic rubber reinforcing agent: PF87 contains no heavy metals or restricted substances, supporting sustainable manufacturing goals.
6. Environmental Compliance and Regulatory Status
- Odor free: No volatile organic compounds; suitable for passenger car inner liners and interior rubber parts. These are odor free functional nano reinforcing fillers for automotive rubber that meet stringent OEM specifications.
- Regulatory compliance: Free from hazardous heavy metals and REACH/RoHS restricted substances (declarations available). PF87 is certified as an eco friendly non toxic rubber reinforcing agent.
- Synergistic flame retardancy: When used with flame retardants, PF series exhibits a synergistic effect.
- Lower carbon footprint: Compared to carbon black production, mineral fillers have significantly lower CO₂ emissions.
7. Technical Summary and Application Recommendations
| Application | Recommended Grade | Key Rationale |
| Tire inner liner (partial replacement of N660) | PF87 | Nano reinforcing filler for tire inner liner; improved gas barrier, better processability, reduced iridescence. |
| Tire tread / belt compound | PF87 / PF91 | Reinforcement near N550; also serves as functional mineral filler to replace carbon black N550 in tread formulations. |
| Light colored EPDM seals, hoses | PF87 | High whiteness lamellar structure mineral filler for EPDM seals providing excellent reinforcement and smooth surface. |
| Low compression set seals (peroxide cure) | PF93 | Excellent compression set properties |
| NBR oil resistant parts | PF91 | Good aging resistance, cost effective |
| High loading, low cost general rubber goods | PF81 | Cost advantage |
The entire PF series functions as an activated nano composite filler for polar and nonpolar rubber, offering formulators a single platform for diverse polymer systems. For any application requiring high gas barrier rubber compounding fillers, low odor rubber fillers for automotive interior, or preventing surface iridescence in rubber products, PF87 and its complementary grades provide a proven, production ready solution.
Access Technical Data and Sample Support
For the following resources, please visit www.sanezenrubber.com or contact a technical sales representative:
- Full test report of PF87 in tire inner liner compounds (including Mooney viscosity, cure curves, gas barrier data) – demonstrating how to improve gas barrier properties of tire inner liner using a partial replacement for carbon black N660.
- TDS (Technical Data Sheet) for each grade
- Free sample (500 g) for internal validation
- Customized formulation recommendations for different rubber matrices and cure systems, leveraging activated nano composite filler for polar and nonpolar rubber technology.
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