Evonik Vestamid E47-S3 is a polyether block amide (PEBA) thermoplastic elastomer in which hard polyamide 12 blocks and soft polyether blocks form a segmented block copolymer. The E47 designation places the nominal hardness at 47 Shore D under ISO 868; the S3 suffix is the supplier’s stabilization-modifier code for a heat and light stabilization package. Because the polyether phase provides elastomeric recovery and the polyamide 12 phase provides melt processability and elevated-temperature structure, the material is used in applications where conventional plasticized thermoplastics would lose flexibility through plasticizer migration or where thermoplastic polyurethane may be too dense or hydrolytically sensitive. Representative supplier data list a density of 1.01 g/cm³ under ISO 1183-1 and a tensile modulus near 80 MPa under ISO 527-1/-2. These values are not specification minima; they are starting points for design calculations and are confirmed by certificate of analysis for each production lot.

The full trade designation Evonik Vestamid E47-S3 should be used in procurement specifications to distinguish it from other Vestamid E grades and from polyamide 12 homopolymer or copolyamide grades. Certification documents typically reference the supplier product code, lot number, and batch-specific melt volume-flow rate and density values. The material is supplied as pellets and can be processed without external plasticizer or impact modifier. Color concentrates should be evaluated for carrier resin compatibility; a carrier resin with poor melt viscosity match can produce streaking or variable light-stabilizer dispersion in the final part.

Does Heat and Light Stabilization Alter the Rheological Profile During Melt Processing?

The stabilization package does not usually shift the melt viscosity curve enough to require a new process in comparison with unstabilized PEBA of equivalent hardness, but it can extend the time before oxidative discoloration is observed at the die. Melt volume-flow rate for this hardness segment is approximately 10 cm³/10 min at 230 °C under a 10 kg piston load when measured to ISO 1133-1. The melting point of the polyamide 12 hard segment is approximately 168 °C under ISO 11357-3. The stabilization package protects the polymer backbone from radical propagation in the polyether phase, where oxidative attack proceeds more rapidly than in the polyamide phase. However, the additive package does not remove the pre-drying boundary: residual moisture above 0.10 % by weight can hydrolyze amide links at melt temperature and reduce tensile elongation at break, even when the dried pellet appearance is unchanged. Typical dry-air drying at 80 °C is recommended until the residual moisture target is reached; hopper dryers with a dew point of -40 °C or below prevent rehumidification during long molding campaigns.

Accelerated aging evaluation typically uses xenon-arc lamps filtered to daylight radiation under ISO 4892-2 cycle 1; specimens are exposed at a black standard temperature of 65 °C and relative humidity controlled by the standard. Tensile elongation after exposure is compared to unexposed controls with ISO 527-1/-2. The stabilization package works by reducing the number of chain scission events in the polyether phase; however, stabilizer consumption is finite and cannot be replenished after the component enters service.

Before melt processing is attempted, the drying unit should be sized for the actual throughput, because a hopper residence time that is too short can leave moisture in the center of the pellet and produce lot-to-lot variation in post-molding elongation. On production-scale single-screw extruders with L/D ratios of 24:1 to 30:1, a reverse temperature profile from 190 °C in the rear zones to 210–230 °C at the die is often used to restrict shear heating in the polyether blocks. For injection molding, barrel settings of 200–240 °C and mold temperatures from 30 °C to 50 °C are consistent with supplier guidance for this Shore D range. Melt temperatures above 250 °C during extended hold times can produce oxidative gel particles and loss of elastic recovery even with the heat stabilization package. Screw designs should use a compression ratio between 2.5:1 and 3.0:1; high-compression screws may generate excessive frictional heat and reduce the available processing window.

Representative Physical Property Envelope for E47-S3

The combination of 47 Shore D hardness and a flexural modulus near 70 MPa under ISO 178 places E47-S3 in the mid-flexibility range of the Vestamid E line. Tensile stress at break approximately 44 MPa and elongation at break above 300 % under ISO 527-1/-2 indicate a ductile failure without a sharp cold-drawing instability. The abrasion loss of approximately 70 mm³ under ISO 4649-A is used by cable jacketing and pneumatic tubing manufacturers as a screening value; field wear rate is not identical to the test result because mating surface roughness, contact pressure, and sliding velocity shift the local temperature at the wear interface.

Equilibrium water absorption is reported below 1.0 % by weight under ISO 62 for general atmospheric exposure; the absorbed water acts as a mild plasticizer in the polyamide hard segments and may lower tensile modulus by a small amount. The grade is therefore conditioned before mechanical testing when comparative data are required to avoid moisture-induced shifts in stiffness or elongation.

When the Service Environment Demands High Deformation Without Yield Failure

Injection-molded sports equipment, seals, gaskets, and flexible tubing are produced from E47-S3 because the elastomeric structure permits repeated deformation and recovery without the localized necking observed in semi-crystalline polyamide 12 homopolymer. Components are frequently evaluated for compression set using ISO 815-1; published data for this specific grade is limited, so qualification programs should generate part-specific values under the exact time, temperature, and strain condition. Notched Charpy impact tests to ISO 179-1/1eA at 23 °C typically show no break, but no-break behavior at -40 °C should not be assumed without testing. The low density of 1.01 g/cm³ reduces part mass in high-volume molded components, and the light stabilization package is relevant for parts that remain visible or installed outdoors.

Extruded pneumatic and cable protection tubes made from E47-S3 are often checked for dimensional stability under relevant product standards rather than a universal PEBA standard. When the application requires continuous UV exposure, accelerated weathering following ISO 4892-2 is used to compare retained elongation at break against an unstabilized control. The exact retained percentage depends on irradiance, black standard temperature, and specimen thickness; published multi-year outdoor data for this precise grade is limited. For that reason, accelerated weathering data should be used only for relative screening, and outdoor service life should be validated by specimen exposure at the intended installation site or by a recognized weathering reference program.

Comparing E47-S3 with PA12 Homopolymer and Adjacent PEBA Grades

Relative to unreinforced PA12 homopolymer, which typically shows tensile modulus above 1,000 MPa under ISO 527-1/-2, E47-S3 is an elastomer. The polyether soft blocks lower hydrogen bond density and crystallinity, but the PA12 hard segments preserve a melting point near 168 °C under ISO 11357-3. This produces a different service signature: PA12 homopolymer yields and draws locally, while E47-S3 tends to deform and recover elastically until ultimate break. Against the Vestamid E hardness ladder, E40-S3 nominally sits at 40 Shore D and E55-S3 at 55 Shore D under ISO 868. Moving from E40-S3 to E47-S3 raises tensile modulus and reduces elastic compliance; moving from E47-S3 to E55-S3 increases load-bearing capacity but can reduce elongation at break and increase bending stiffness. Selection among these grades is therefore driven by the required balance between stiffness and cyclic flexibility.

The heat and light stabilization package is the principal difference from a standard or only heat-stabilized PEBA of similar hardness. In accelerated weathering under ISO 4892-2, E47-S3 retains a larger fraction of initial elongation at break than an unstabilized control after equivalent radiant exposure. Because the test is comparative and does not reproduce all terrestrial climates, a single hour count cannot be used as a universal lifetime. The grade may be supplied with regulatory statements under EU REACH Regulation (EC) No 1907/2006 and EU RoHS Directive 2011/65/EU; end-use markets such as food contact, potable water, or medical devices require additional grade-specific confirmatory testing under their own standards.

Compared with other polyether block amides of equivalent Shore D hardness, E47-S3 is differentiated by the PA12 hard block chemistry and the supplier-specific stabilization package; direct comparisons require side-by-side testing because hardness alone does not determine flexural fatigue or weathering retention. Published data for cross-supplier comparisons is limited.

Continuous service above 120 °C in load-bearing parts is a defined operational boundary for this material, not a fixed failure temperature. Oxidative aging of the polyether segment accelerates with increasing service temperature, and design validation should use ISO 2578 thermal endurance principles or application-specific heat aging. The material should not be processed without pre-drying, and regrind should be limited to a ratio that keeps post-molding tensile elongation at break within the lot-specific control window established during part qualification. Chemical contact with strong acids, strong oxidizing agents, or certain polar solvents at elevated temperature can attack the polyamide hard segment or swell the polyether phase, so compatibility testing under the intended chemical environment is required before use.