Biopolyamides
(Polyalkylene Sebacamides)

Properties and Applications

Biobased polyamides are a new class of bioplastics that are derived from renewable resources such as natural fats and oils. The majority of these bioamides are based on sebacic acid with the exception of polyamide 11 (also called Nylon 11 or Polyundecanolactam) which is based on undecylenic acid. Both fatty acids can be derived from castor oil. The sebacic acid based polyamides are prepared by step-growth polymerization of the diacid with a diamine such as hexamethylenediamine (C6) and decamethylenediamine (C10) yielding polyamide 6/10 and polyamide 10/10. PA11 is produced by first brominating the double bond of the undecylenic acid followed by reaction with ammonia yielding 11-aminoundecanoic acid which is then polymerized to PA11.¹

All three polyamides have excellent mechanical properties including high tensile strength, flexibility, toughness and good resilience and abrasion resistance. They offer several advantages over their traditional counterparts PA6 and PA6/6 including lower moisture absorption (<1%), higher impact strength, and improved chemical resistance. They also have a higher melting point, much higher elongation at break and lower modulus.

Biopolyamides are used in many (demanding) applications such as automotive fuel lines, pneumatic air brake tubing, electrical cable jacketing, flexible  oil and gas pipes, and powder coatings. Some novel applications include tooth brushes, carpets, tires, sporting goods (sports shoes and outdoor apparel), and electronic casings.

¹A. Chauvel, G. Lefebvre, Petrochemical Processes, Editions Technip (1989)
²According to DSM, PA46 has the highest melting point of all bio-plastics
³According to Grand View Research, the global bio-polyamide market was valued at US$ 110M in 2016 (Est. CAGR: 12.9 %).