Biobased chiral semi-crystalline or amorphous high-performance polyamides and their scalable stereoselective synthesis.

The use of renewable feedstock is one of the twelve key principles of sustainable chemistry. Unfortunately, bio-based compounds often suffer from high production cost and low performance. To fully tap the potential of natural compounds it is important to utilize their functionalities that could make them superior compared to fossil-based resources. Here we show the conversion of (+)-3-carene, a by-product of the cellulose industry into ε-lactams from which polyamides. The lactams are selectively prepared in two diastereomeric configurations, leading to semi-crystalline or amorphous, transparent polymers that can compete with the thermal properties of commercial high-performance polyamides. Copolyamides with caprolactam and laurolactam exhibit an increased glass transition and amorphicity compared to the homopolyamides, potentially broadening the scope of standard polyamides. A four-step one-vessel monomer synthesis, applying chemo-enzymatic catalysis for the initial oxidation step, is established. The great potential of the polyamides is outlined.