Products · EMAA
Ethylene methacrylic acid (EMAA) copolymers are a related family to EAA in which the acid comonomer is methacrylic acid (MAA) rather than acrylic acid. The bulkier MAA group delivers different properties: higher toughness, lower crystallinity at equivalent acid content, and easier neutralization to ionomer. EMAA is the primary feedstock for sodium and zinc ionomers (e.g., DuPont Surlyn) and is also used directly in flexible films, extrusion coatings, and adhesive tie layers where its combination of clarity and toughness is valued.
Section 1
A reference overview of the molecular architecture and the design variables that govern the performance of this polymer family.
EMAA is produced by high-pressure free-radical copolymerization of ethylene and methacrylic acid. The α-methyl group on MAA sterically hinders the acid carbonyl, slightly reducing hydrogen-bonding strength compared to EAA at equivalent acid content. However, the same steric bulk also disrupts polyethylene crystallinity more effectively, giving EMAA higher clarity, lower density, and better low-temperature flexibility than comparable EAA grades. Partial neutralization of EMAA with sodium or zinc cations produces ionomers, where ionic clusters act as physical crosslinks, dramatically increasing toughness, puncture resistance, and optical clarity.
Section 2
Typical property ranges across commercial grades. Test methods are listed in the rightmost column for traceability to public manufacturer data sheets.
Compared to EAA at equivalent acid content, EMAA grades tend to show higher clarity, lower density, and improved low-temperature toughness. The MAA comonomer also enables more uniform neutralization, which is why the world's most widely used ionomer (Surlyn) is based on EMAA rather than EAA.
| Property · 性能 | Typical Range · 典型范围 | Test Method · 测试方法 |
|---|---|---|
| Density · 密度 | 0.920 – 0.950 g/cm³ | ASTM D792 |
| Melt Index (190°C/2.16 kg) · 熔指 | 1.0 – 25 g/10 min | ASTM D1238 |
| Tensile Strength at Yield · 屈服拉伸 | 9 – 16 MPa | ASTM D638 |
| Elongation at Break · 断裂伸长 | 450 – 650 % | ASTM D638 |
| Vicat Softening · 维卡软化 | 55 – 85 °C | ASTM D1525 |
| Clarity · 透明性 | High (compared to EAA at same MFI) | Visual · 目测 |
| Acid Content · 酸含量 | 5 – 12 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.
EMAA is the primary feedstock for sodium and zinc ionomers (DuPont Surlyn). Ionomers are used in golf ball covers, packaging films with exceptional clarity and seal strength, and skin packaging for consumer goods.
Cast and blown EMAA films offer high clarity, good toughness, and direct adhesion to aluminum foil. Used in medical device packaging, retort pouches, and stand-up pouches where optical clarity through the structure is a brand asset.
EMAA extrusion coating on paper, board, and aluminum foil provides heat sealability, moisture resistance, and adhesion. Common in aseptic carton, pet food, and industrial packaging where the combination of toughness and adhesion is needed.
EMAA functions as a tie layer between polyolefin and polar substrates. Slightly lower acid reactivity than EAA, but the MAA group enables better adhesion to certain engineering plastics such as polyamides under high-humidity conditions.
Section 4
Key processing parameters and equipment considerations. Contact our business manager for grade-specific processing recommendations.
| Melt Temperature | 250 – 280 °C (lower than EAA due to better melt strength) |
| Die Temperature | 260 – 280 °C for flat-die extrusion coating |
EMAA is more thermally stable than EAA above 280 °C due to lower acid reactivity. Ionomer conversion (partial Na or Zn neutralization) is done in the reactor or compounding step — not a downstream process. Equipment for ionomer processing should be corrosion-resistant due to residual sodium acetate.
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 EMAA over EAA when the application requires higher clarity, better low-temperature toughness, or downstream ionomer conversion. For pure adhesion-driven applications where cost is the primary driver, EAA is usually the better economic choice. For high-clarity skin packaging or golf ball covers, ionomer (neutralized EMAA) is the only practical option.
Section 6
Reference grades from publicly available manufacturer catalogs. Complete catalog available on request.
| Grade | Manufacturer | Key Properties | Typical Use |
|---|---|---|---|
| Nucrel® 925Internal snapshot · original TDS on request | DuPont | 9% MAA · 25 MI · Film grade | Flexible packaging · Skin film |
| Nucrel® 960No vendor TDS · source on request | DuPont | 9% MAA · 60 MI · High flow | Extrusion coating · Adhesive layer |
| Surlyn® 8940 (ionomer) | DuPont | Na ionomer of EMAA · Toughness | Skin packaging · Golf ball cover |
| EMAA-N15 | Domestic · 国产 | 10% MAA · 8 MI | Tie layer · General coating |
Section 7
Cross-references to industry-specific applications and case studies.