Products · EAA
Ethylene acrylic acid (EAA) copolymers are workhorse adhesion polymers for extrusion coating, multilayer tie layers, and aluminum foil lamination. The carboxylic acid functionality — typically 7% to 15% acrylic acid by weight — delivers strong hydrogen bonding to aluminum, paper, polyamide, EVOH, and other polar substrates. Bond strengths achievable with EAA are difficult to match with unmodified polyolefins, which is why EAA is the industry default for aseptic carton, toothpaste tube, and retort pouch structures. Reference grades from DuPont (Nucrel), ExxonMobil (Escor), and SK include both extrusion-coating and film-grade variants across a wide melt index range.
Section 1
A reference overview of the molecular architecture and the design variables that govern the performance of this polymer family.
EAA is a random copolymer of ethylene and acrylic acid (AA), produced by high-pressure free-radical polymerization similar to LDPE. The acrylic acid monomer is incorporated randomly along the polymer backbone, with no long AA runs and no graft structure. Acid content is the primary design variable: low acid (7-9%) gives flexible, easy-processing grades suited to extrusion coating; mid acid (9-12%) balances adhesion and processability; high acid (12-15%) maximizes adhesion and tie-layer performance but raises moisture sensitivity and melt strength. The acid functionality is stable under processing but can be partially neutralized with sodium or zinc cations to form ionomer variants (Surlyn) for higher tensile and puncture resistance.
Section 2
Typical property ranges across commercial grades. Test methods are listed in the rightmost column for traceability to public manufacturer data sheets.
EAA combines the processing window of LDPE with the adhesion chemistry of an acid-functional polymer. Typical property ranges across commercial grades are summarized below. The combination of high elongation, low heat-seal initiation temperature, and direct metal adhesion is uncommon in unmodified polyolefins and is the reason EAA is specified in many flexible packaging constructions.
| Property · 性能 | Typical Range · 典型范围 | Test Method · 测试方法 |
|---|---|---|
| Density · 密度 | 0.925 – 0.960 g/cm³ | ASTM D792 |
| Melt Index (190°C/2.16 kg) · 熔指 | 1.5 – 30 g/10 min | ASTM D1238 |
| Tensile Strength at Yield · 屈服拉伸 | 8 – 18 MPa | ASTM D638 |
| Elongation at Break · 断裂伸长 | 400 – 700 % | ASTM D638 |
| Vicat Softening · 维卡软化 | 60 – 90 °C | ASTM D1525 |
| Heat Deflection (0.45 MPa) · 热变形 | 38 – 55 °C | ASTM D648 |
| Acid Content · 酸含量 | 7 – 15 wt % | Titration · 滴定法 |
Section 3
The major application areas for this polymer family, each illustrated with a brief description of how the material is specified and used.
EAA is widely used as a tie layer between aluminum foil and polyethylene in toothpaste tubes, beverage cartons, and aseptic packaging. The carboxylic acid groups form strong hydrogen bonds with the aluminum oxide surface, giving bond strengths of 3-8 N/15mm — values difficult to achieve with unmodified LDPE even with corona treatment.
In co-extruded multilayer films combining PE with polyamide (PA) or EVOH barrier layers, EAA serves as the adhesive tie between the polyolefin skin and the polar barrier. Typical constructions include PE / EAA / EVOH / EAA / PE for vacuum packaging and PE / EAA / PA / EAA / PE for thermoforming food trays.
EAA extrusion coating on kraft or carton board provides a moisture-and-grease barrier for food service, pet food, and industrial packaging. Lower melt index grades (1.5-7 MI) are preferred for coating weights above 15 g/m² to prevent neck-in and edge bead.
Higher acid content EAA grades (12-15% AA) can be formulated into hot-melt adhesives for bookbinding, packaging, and assembly applications. The acid functionality improves adhesion to difficult substrates and offers tunable open time via acid-content selection.
EAA complies with major food contact regulations (US FDA 21 CFR 177.1310, EU 10/2011) for use in direct and indirect food contact structures. It is the workhorse adhesion polymer for retort pouches, vacuum bags, and stand-up pouches where seal integrity through thermal processing is critical.
Section 4
Key processing parameters and equipment considerations. Contact our business manager for grade-specific processing recommendations.
| Melt Temperature | 260 – 290 °C (depending on AA content and equipment) |
| Die Temperature | 270 – 290 °C for flat-die extrusion coating |
EAA is sensitive to thermal degradation above 300 °C — residence time should be minimized and equipment cleared of prior PE/PP residues. Corona or flame treatment of polar substrates improves bond strength. For tie-layer co-extrusion, a melt temperature of 240-260 °C is typical to avoid excessive reactivity with adjacent PA or EVOH layers.
Section 5
A summary of when this polymer family is the right choice and what to consider as alternatives. For project-specific grade selection, contact our business manager.
Choose EAA when the application demands strong adhesion to polar substrates (aluminum, paper, polyamide, EVOH) and high-temperature resistance is not critical. For higher-temperature metal adhesion or downgauging, consider EAA ionomer (Surlyn) or maleic-anhydride-grafted polyolefins. For pure oxygen-barrier film without adhesion requirements, EVOH or PVDC coatings are more cost-effective. For thermal stability above 150 °C continuous, EMAA or specialty acid copolymers are preferred.
Section 6
Reference grades from publicly available manufacturer catalogs. Complete catalog available on request.
| Grade | Manufacturer | Key Properties | Typical Use |
|---|---|---|---|
| Nucrel® 0407Internal snapshot · original TDS on request | DuPont | 9% AA · 7 MI · Extrusion coating · Carton | Beverage cartons · Foil lamination |
| Nucrel® 0908HCNo vendor TDS · source on request | DuPont | 9% AA · 8 MI · High clarity | Transparent packaging · Food contact |
| Escor® 5100No vendor TDS · source on request | ExxonMobil | 11% AA · 7 MI · Tie layer | Multilayer film · Barrier structures |
| Primacor® 1410No vendor TDS · source on request | SK Functional Polymer | 9.5% AA · 10 MI · Extrusion | Adhesive extrusion · Coating |
Section 7
Cross-references to industry-specific applications and case studies.