Innovative and sustainable alternatives for conventional polyamides
The majority of polyamides used in plastics processing are produced from fossil raw materials and have a comparatively high CO₂ footprint for polymers. Substitution by polymers with a lower CO₂ footprint, such as polyolefins and polyesters, is not possible in many cases due to the technical properties required.
Polyamides that are fully or partially biobased offer an alternative from the same polymer class and thus comparable material and processing properties. The use of biomass for the production of polyamides reduces dependence on fossil resources as well as greenhouse gas emissions, because plant-based raw materials absorb CO2 from the atmosphere, which is not further emitted at the end of the product life cycle.
Overview of the biobased Polyamides
Innovative and sustainable polyamide
AKROMID® NEXT G3 GF 30 1 L CI black (8376) is a glass fibre reinforced PA 6.9/PP blend with biobased content and suitable for weight-reduced, sustainable applications. PA 6.9 is partially biobased (sunflower oil). In addition, the product is certified according to ISCC PLUS: 33% (allocation factor*) of the fossil raw materials are replaced by sustainably certified, biomass-balanced PP.
Similarly, the corresponding product can be supplied with a REDcert² certification under the brand label AKROMID® NEXT G3 GF 30 1 L CR black (8314). You can read about the general advantages of PA/PP blends under AKROMID® LITE.
The partly biobased AKROMID® NEXT 5.6 3 GF 30 natural (8405) is a HMD-free (hexamethylenediamine) alternative to conventional PA 6.6 compounds with comparable properties. For example, the melting point of 253°C is only about 10°C lower than PA 6.6. PA 5.6 has a lower CO2 footprint and is partly produced from renewable raw materials ( biobased share = 45%*). Increased moisture absorption should be noted. For components with increased impact loads, we also offer AKROMID® NEXT 5.6 3 GF 30 S3 black (8444), a dry impact modified version, also with 30% glass fibre reinforcement.
Reduced water absorption and increased chemical resistance
The base polymer of AKROMID® NEXT 5.10 3 GF 30 natural (8406) is 100%* biobased. The properties are similar to the partly biobased PA 6.10. Due to the longer repeating unit, both PA 6.9 and PA 5.10 have a lower proportion of the characteristic amide groups, which leads to reduced water absorption and increased chemical resistance. The figure shows an example of resistance to CaCl2, which is used for example in road salt to lower the freezing point or as a dust binder for unpaved roads.
Hot air storage causes thermooxidative damage to the surface of polyamides, resulting in discoloration and loss of mechanical properties, a process also known as aging. The process occurs primarily at the surface, leaving an undamaged core, as shown in the figure. The thickness of the oxidized layer is a visual measure of the degree of aging.
In the heat aging test at 180 °C, the behavior of the considered biobased polyamides is between PA 6 and the more vulnerable PA 6.6, which can be seen in the drop of tensile strength (see figure).
Of course, AKROMID® NEXT compounds contain a heat stabilization, which strongly improves the aging behavior.
Innovative and sustainable polyamide
AKROMID® NEXT U ICF are carbon fiber reinforced PA 11 compounds that combine performance with sustainability.
The PA 11 is produced from the oil of castor beans (biobased share > 97%*). The carbon fibers are processed from residues of carbon fiber mats (post-industrial recycling share = 100%). In addition, the compounds allow sustainable lightweight construction by combining low density, high stiffness and strength with high ductility. Due to the long carbon chain of the monomer, molded parts made of AKROMID® NEXT U have a low moisture absorption, resulting in a high dimensional stability and a low influence of moisture on the mechanical properties. A strong advantage compared to molded parts made of conventional polyamides, such as PA 6 or PA 6.6.
AKROMID® NEXT U3 ICF 40 1 black (8238) is suitable for demanding applications with a E-modulus of 20 GPa, a strength of 190 MPa and a density of 1.24 g/cm³. With an elongation at break of 3.5%, the material is still very ductile and is therefore also used in areas with high impact strength requirements, such as in the sports and leisure industry.
Due to the melting point of 189°C and the wide processing temperature range, AKROMID® NEXT U ICF compounds are also particularly suitable for the processing with methods of additive manufacturing. Thus, AKROMID® NEXT U3 ICF 10 1 black (8231) can be used for the production of filaments for Fused Filament Fabrication (FFF). With higher reinforcement contents, AKROMID® NEXT U3 ICF 30 1 (8233) is also suitable for the production of large-volume parts with high throughput above 1 kg/h in additive manufacturing with screw extrusion (Screw Extrusion additive Manufacturing).
¹ The allocation factor indicates the percentage of fossil raw materials that are replaced by sustainable, certified materials (biomass/recyclate) in the value chain. It is based on the mass balance approach and does not indicate how much biomass or recyclate is actually included in the product. It always refers to the organic content (e.g. polymers) of the product.
² The biobased product actually contains biomass. The biobased portion of the material can be quantified by the C14 method (e.g. according to ASTM D6866, EN 16640).
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Disclaimer: All specifications and information given on this website are based on our current knowledge and experience. A legally binding promise of certain characteristics or suitability for a concrete individual case cannot be derived from this information. The information supplied here is not intended to release processors and users from the responsibility of carrying out their own tests and inspections in each concrete individual case. AKROMID®, AKROLEN®, AKROLOY®, AKROTEK®, ICX®, PRECITE® and DIA(hr)LOG® are registered trademarks of AKRO-PLASTIC GmbH.