Key Properties of Rilsan® PA11
For over 70 years, Arkema has been a world leader in specialty bio-based polyamides derived from castor oil. Rilsan® PA11 has become the global reference when it comes to flexible polyamide resins with outstanding impact, durability, and chemical resistance properties. Its crystalline morphology allows this special polymer to differentiate itself from petroleum-based alternatives.
Arkema offers a wide array of natural, pigmented, filled, plasticized, and alloyed grades. Also included in this portfolio is Arkema's award winning Rilsan® HT (high temperature performance) and Rilsan® Clear transparent polyamide series.
Bio-based / Renewable
Rilsan® PA11 resins are exceptionally lightweight with a neat resin density of only 1.03 g/cm3. With many industries looking for ways to reduce weight in their designs, Rilsan® polyamide 11 grades can provide long term durability and strength, making metal replacement even more possible.
PA11 can also be used as the polymer matrix in composite designs for even more strength and further weight reduction.
Chemical & Fuel Resistance
Rilsan® PA11 has excellent chemical resistance to not only grease and hydrocarbons, but acids, bases, and salts too. During exposure, even at elevated temperatures, Rilsan® polyamide 11 maintains good dimensional stability and resists degradation of the polymer matrix. This is especially important for extreme applications like those in the oil and gas industry where the polymer is exposed to elevated temperatures and pressures and must provide high performance for many decades. Rilsan® PA11 also maintains very low permeation to hydrocarbons, making fuel lines a very popular application.
Rilsan® PA11 is available in a wide range of flexibilities. This is made possible by the addition of plasticizers (to increase flexibility) and carbon or glass fiber/beads (to increase rigidity). PA11 also maintains its properties after exposed to moisture, compared to short chain polyamides like PA6 and PA66, which are very susceptible to losing performance over time.
Compared to PA11, other polyamides generally exhibit more hydrophilic behavior due to their higher frequency of the amide groups in the polymer chain (more amide groups = more polar polymer chain). Because of this, Rilsan® PA11 can be used in high humidity where other polyamides might have issues. The same is true for absorption of other polar liquids like alcohols, acids, and esters.
Dimensional variation (after 25 week immersion in 20ºC water)
|Length variation||Weight variation|
|Rilsan® PA11||0.2 - 0.5%||1.9%|
|PA6||2.2 - 2.7%||9.5%|
Rilsan® PA11 generally outperforms PA12 when it comes to impact resistance. Polyamide 11 is especially tough at low temperatures and has been observed to be twice as resilient as polyamide 12 at -30ºC during a notched Charpy impact test. This incredible toughness can be attributed to Rilsan® PA11's fine crystalline grid and spherolitical structure, as well as its molecular weight and polydispersity.
Compared to other engineering polymers, Rilsan® PA11 exhibits good abrasion and crack propagation resistance. This is largely due to its smooth surface finish that induces an extremely low coefficient of friction. As isllustrated in the chart, PA11 also features better abrasion resistance (lower material loss) than PA12 for both plasticized and unplasticized grades.