The graphs below show absolute values as well as the percentage retention of tensile properties of EcoPaXX® vs. PA66 for 30%GF grades after 1,000 hours exposure to 50/50 water/glycol mixture at 135°C. EcoPaXX® has ca. 20% higher retention of tensile properties compared to PA66 grade. This results in a five-fold increase in weldline performance (tested on tensile bars) as well as a three-fold increase in product lifetime (tested on automotive expansion tank, design dependent). Therefore, it is possible to design parts with lower thickness and hence weight compared to PA66 while maintaining similar or higher performance.
Tensile Properties after Moisture Uptake
The graphs below show comparative data of thermal properties, moisture uptake and dry vs. conditioned tensile modulus for different unfilled polymers. EcoPaXX®'s combination of short C4 chain and long C10 chain results in a unique balance of high crystallinity/stiffness combined with low moisture uptake and high chemical resistance. Specifically, EcoPaXX® PA410 has 30% lower moisture uptake than PA66 while exhibiting similar glass transition (70°C) and melt temperature (250°C). As a result, EcoPaXX® has the highest conditioned modulus (1,7GPa) among aliphatic polyamides.
EcoPaXX® has specialized food contact and drinking water grades, which are approved by all major institutions (e.g. KTW, W270, NSF61, WRAS, ACS, EU 11/2011, FDA). EcoPaXX® is approved for both warm and hot water applications. Data below is shown for the percentage of water uptake of 50%GF filled grades at 50% and 100% relative humidity. Due to its low moisture uptake and high mechanical strength, EcoPaXX® shows excellent hydrolysis resistance with no water leakage in lifetime cycle tests up to 1 Million cycles. EcoPaXX® drinking water grades have higher Tg of ca. 85°C and show superior long-term hydrolysis resistance in hot water aging (110°C) compared to low Tg PPA.
The graph to the right shows data for mechanical environmental stress cracking tests under the influence of a calcium chloride solution to mimic road salt resistance. A 3mm thick notched tensile bar is subjected to a force of 10N/mm at 75°C in saturated CaCl2 solution until failure. The data shows that EcoPaXX® is extremely resistant to CaCl2 salt with no mechanical failure even after 2,500 hours being submerged in the solution, especially when compared to ca. 5 hours for PA66.
| Environmental stress cracking test | |
| Material | hrs. in test until failure |
| PA6-GF30 | < 1 |
| PA46-GF30 | < 1 |
| PA46-GF30 annealed | -50 |
| PA66-GF30 | -5 |
| EcoPaXX® 30GF | >2500 |
EcoPaXX® can be processed very similarly to PA66. It has a very wide processing window (270-310°C) and high melt stability. Its faster crystallization rate vs. PA66 results up to 20% lower cycle times.
At the same time, EcoPaXX® has excellent surface finish even with 30%GF content, making it suitable for decorative applications, such as engine covers.
EcoPaXX® has several grades that are engineered to meet V2 and V0 flammability and high glow-wire temperatures. All EcoPaXX® grades are halogen-free and hence do not release associated toxic compounds upon burning. Dielectric strength data measured according to IEC 60243-1 standard is shown for different unfilled polymers. Samples were measured before and after conditioning at 95% relative humidity at 40°C for 120 hours. Spherical electrodes of 20mm were used with a voltage increase of 500V/s.
The data shows that EcoPaXX® has similar dielectric strength as PA66 in the dry state, but significantly higher dielectric strength after conditioning. This makes EcoPaXX® more insulating, resulting in higher safety for electrical applications. It also means insulating parts with EcoPaXX® can be designed thinner than with PA66 without sacrificing product safety.
EcoPaXX® carbon footprint is assessed cradle-to-gate, using DSM‘s in-house lifecycle assessment experts. The graph below shows the carbon footprint of EcoPaXX® compared to other common polyamides. EcoPaXX® has the lowest carbon footprint amongst common polyamides, including biobased polyamides. The Carbon footprint can be lowered further if biomass balancing is used for the C4 monomer. This is an option available for certain grades upon customer request. Mass balancing does not change material properties and is externally certified through ISCC.
Our team can assist with calculations for specific EcoPaXX® grades, and we also work with our customers on cradle-to-grave assessments for specific end applications.
