Evonik Industries (Essen / Germany; www.evonik.com) has added a group of bio-based polyamides to its “Vestamid” range of high performance polymers. The products will be sold under the “Vestamid Terra” brand name and are based on monomers produced partly or entirely from fatty acids, most importantly castor oil. The company is also developing additional polyamides from renewables based on palm kernel and rapeseed oils.

Two castor oil-based polyamides are currently offered. “Terra DS" is a 100% bio-based PA 1010. Its properties fall between high-performance long-chain polyamides such as PA 12 and PA 1212 and the shorter chain standard polyamides PA 6 and PA 6.6. “Terra HS” is a polyamide 610 that contains approximately 60% renewable raw materials. Technically, it occupies a position between the high-performance PA 612 and the standard polyamides PA 6 and PA 6.6.

Evonik said that Terra moulding compounds are semicrystalline and offer high mechanical strength and good resistance to chemicals and stress cracking. They also have high to very high heat deflection temperatures and a low absorption capacity for water, so that mechanical properties are retained even at high humidity.