GETA QUOTE
Even after super-toughening modification, its low-temperature toughness heavily relies on elastomer additives.
PA12 is a long-carbon-chain nylon with intrinsically excellent low-temperature ductility, low water absorption, stable low-temperature mechanical properties without heavy toughener loading.
Its ductile-brittle transition temperature is lower than -60℃.
| Performance Item | PA66 | PA12 |
|---|---|---|
| Ductile-brittle transition temperature | ≈ -20 ~ -25℃ (neat resin) | ＜ -60℃ (neat resin) |
| Water absorption (23℃, saturated) | 7.5~8.5% | 1.3~1.5% |
| Low-temperature toughness (neat polymer) | Poor; easy brittle fracture below -25℃ | Excellent; remains flexible at -40℃/-50℃ |
| Approach to achieve -40℃ resistance | Must add 15~22% POE-g-MAH toughener; rigidity drops significantly | 5~10% toughener is sufficient; some grades can meet -40℃ requirements without toughening |
| Impact change after moisture absorption | Huge difference between dry & conditioned state; low-temperature impact declines sharply when wet | Minor influence of moisture on low-temperature properties |
| Low-temperature dimensional stability | Susceptible to moisture & temperature variation | Outstanding; low shrinkage & low warpage under thermal cycling |
| Rigidity retention at low temperature | Modulus rises obviously at low temperature, material becomes stiffer | Moderate modulus increase; less tendency to harden |
| Typical limit of service temperature | Toughened grade: reliably -40℃ | Neat grade: reliably -50℃ and below |
| Cost level | Medium | High |
Neat Resin Difference
Raw PA66 cannot withstand -40℃ environment; sharp cracking occurs under impact.
Virgin PA12 maintains ductility at -40℃ without modification.
Modified Grades for -40℃ Working Condition
Toughened PA66: Reliable for impact load at -40℃, but sacrifices tensile modulus, surface hardness. Water absorption remains a big concern for precision parts.
Modified PA12: Only small amount of toughener needed. Suitable for dynamic parts requiring consistent performance under alternating humidity and extreme low temperature.
Critical Weakness of PA66 in Low-Temperature Application
PA66 absorbs water; water acts as internal plasticizer.
Once dried thoroughly in low-temperature environment, toughness further decreases.
PA12 low-temperature performance barely affected by humidity.
Typical Application Recommendation
Choose toughened PA66:
Budget constrained structural parts, temporary low-temperature exposure, parts with no strict dimensional precision requirement.
Choose PA12:
Pneumatic/hydraulic tubing, outdoor sensor housings, precision moving components, long-term alternating cold & humid environment, strict demand on low-temperature flexibility.
3.Short Version (For quotation & overseas customer communication)
Neat PA66 tends to embrittle around -25°C and requires high dosage of grafted elastomer to achieve -40°C impact resistance, with obvious impact from water absorption.
PA12 is long-chain nylon with inherent superior low-temperature performance, ductile below -60°C, very low water absorption.
It maintains stable toughness at -40°C with little or no toughener.
