Products · PPA
Polyphthalamide (PPA) is a high-performance polyamide family based on aromatic dicarboxylic acids (typically isophthalic acid or terephthalic acid) combined with aliphatic diamines. The aromatic acid content (typically 50-65 mol% of the diacid component) delivers three key advantages over PA66: higher continuous use temperature (160-180°C vs 150°C for PA66), much lower moisture absorption (1.5-2.5% vs 8-9% for PA66 at saturation), and better chemical resistance. PPA is the workhorse for automotive powertrain components (turbocharger air ducts, EGR coolers, oil modules) and SMT connectors where reflow soldering is required. Reference grades from Solvay (Amodel), DuPont (Zytel HTN), and EMS-Grivory (Grivory) cover the full property range.
Section 1
A reference overview of the molecular architecture and the design variables that govern the performance of this polymer family.
PPA is a copolymer of aliphatic diamines (typically hexamethylenediamine or 1,9-nonanediamine) with a mixture of aliphatic (adipic acid) and aromatic (terephthalic acid, isophthalic acid) dicarboxylic acids. The aromatic acid content (typically 50-65 mol% of the total acid component) classifies the polymer as 'phthalamide' rather than purely aliphatic polyamide. The partial aromatic backbone gives higher glass transition temperature (typically 120-135°C vs 50-60°C for PA66), higher melting point (310-330°C for typical grades), and reduced amide group density — the latter being the main reason for the much lower water absorption. PPA is partially crystalline, with slower crystallization than PA66 requiring precise mold temperature control.
Section 2
Typical property ranges across commercial grades. Test methods are listed in the rightmost column for traceability to public manufacturer data sheets.
PPA's defining performance is the combination of high heat resistance (160-180°C continuous, higher than PA66 and approaching PPS territory), low moisture absorption (1/3 to 1/4 of PA66), and excellent chemical resistance. The penalty is processing difficulty: PPA requires higher melt temperatures (310-330°C), tighter drying control, and higher mold temperatures than PA66.
| Property · 性能 | Unfilled PPA | 33% GF PPA | Test Method · 测试方法 |
|---|---|---|---|
| Density · 密度 | 1.15 – 1.20 g/cm³ | 1.40 – 1.50 g/cm³ | ASTM D792 |
| Melt Point · 熔点 | 310 – 325 °C | 310 – 325 °C | ISO 3146 |
| Tg · 玻璃化温度 | 120 – 135 °C | 120 – 135 °C | DSC |
| Tensile Strength · 拉伸强度 | 85 – 100 MPa | 190 – 230 MPa | ASTM D638 |
| Flexural Modulus · 弯曲模ulus | 3.0 – 3.5 GPa | 11 – 14 GPa | ASTM D790 |
| Elongation at Break · 断裂伸长 | 5 – 15 % | 2 – 4 % | ASTM D638 |
| HDT (1.82 MPa) · 热变形 | 120 – 140 °C | 280 – 300 °C | ASTM D648 |
| Water Absorption (24h) · 吸水率 | 0.4 – 0.6 % | 0.3 – 0.5 % | ASTM D570 |
Section 3
The major application areas for this polymer family, each illustrated with a brief description of how the material is specified and used.
PPA is the dominant material for automotive powertrain components exposed to high temperatures and aggressive fluids: turbocharger air ducts, charge air cooler housings, exhaust gas recirculation (EGR) coolers, oil filter modules, and thermostat housings. Heat-stabilized PPA grades with 30-50% GF can survive continuous exposure to 160-180°C engine bay temperatures.
PPA is widely used in SMT (surface-mount technology) connectors where reflow soldering at 260-280°C peak temperature is required. The low moisture absorption of PPA minimizes blistering and dimension change during reflow, and the high HDT provides dimensional stability on the hot solder side of the connector body.
PPA grades with high reflectivity (white or light-colored) are used in LED housings, reflectors, and bezels. The combination of high HDT, low moisture absorption, and color stability under thermal aging is valued in high-power LED applications.
PPA replaces metal in industrial fluid handling applications: pump housings, valve bodies, and chemical process fittings where elevated temperature, chemical exposure, and dimensional stability are required. Common in chemical processing, oil and gas, and water treatment industries.
Section 4
Key processing parameters and equipment considerations. Contact our business manager for grade-specific processing recommendations.
| Melt Temperature | 310 – 330 °C; mold temperature 140 – 160 °C for crystallinity |
| Drying | 120 – 130 °C for 4 – 6 hours (moisture < 0.05%) |
PPA melt temperature is close to its degradation temperature — residence time in the barrel should be minimized. Barrel heaters must reach 320°C reliably. Mold temperature control is critical for crystallinity: 140-160°C for crystalline parts, lower for amorphous skin (used in some connector designs). Post-mold annealing at 170-200°C for 2-4 hours can improve dimensional stability in tight-tolerance parts.
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 PPA when the application requires continuous use temperature above 150°C with low moisture absorption, or when SMT reflow soldering (260-280°C peak) is required. For higher temperatures (>180°C continuous) or broader chemical resistance, PPS or PEEK is preferred. For lower temperatures (<150°C continuous) with similar mechanical performance, PA66 with higher glass-fiber loading is more cost-effective.
Section 6
Reference grades from publicly available manufacturer catalogs. Complete catalog available on request.
| Grade | Manufacturer | Key Properties | Typical Use |
|---|---|---|---|
| Amodel® A-1133Internal snapshot · original TDS on request | Solvay | 33% GF · Heat stabilized · Standard | Automotive powertrain · EGR cooler |
| Amodel® A-4140No vendor TDS · source on request | Solvay | 40% GF · High heat · HS | Turbocharger duct · High-temp automotive |
| Zytel® HTN 51G35HSLRNo vendor TDS · source on request | DuPont | 35% GF · HS · Laser-markable | Connector · SMT reflow capable |
| Grivory® GV-5H | EMS-Grivory | 50% GF · High stiffness | Structural automotive · Pump housings |
Section 7
Cross-references to industry-specific applications and case studies.