Evonik Industries AG (Germany) has added a group of bio-based polyamides to its VESTAMID® family. The polymers, sold under the VESTAMID® Terra brand name, are based on monomers produced partly or entirely from fatty acids.
The most important source is currently castor oil, obtained from the seed of the castor oil plant, which is not used as food or animal feed, so its cultivation does not compete with that of food crops. Evonik is also forging ahead with the development of further polyamides from renewables based on palm kernel and rapeseed oils.
VESTAMID® Terra molding compounds are semicrystalline and therefore distinguished by high mechanical strength and good resistance to chemicals and stress cracking. They are also said to have high to very high heat deflection temperatures and a low absorption capacity for water, so that the good mechanical properties are retained even at high humidity.
VESTAMID® Terra DS has yet another advantage over other polyamides: Despite its crystallinity it is translucent and can therefore be processed into components with good contact transparency.
Evonik currently offers two new castor oil-based polyamides. VESTAMID® Terra DS is a 100% bio-based polyamide 1010. Its property profile bridges the gap between high-performance long-chain polyamides such as PA 12 and PA 1212 and the shorter chain standard polyamides PA 6 and PA 66.
VESTAMID® Terra HS is a polyamide 610 that contains approximately 60% renewable raw materials. From a technical viewpoint, this variant occupies a position between the high-performance polyamide 612 and the standard polyamides PA 6 and PA 66.