Fig. 4: End-of-life options for PAX polyamides.
From: Performance polyamides built on a sustainable carbohydrate core
a, Stress–strain curves of 4S PA-10,DGX over three cycles of high-shear extrusion at 250 °C. Tensile specimens were injection moulded. The tabulated tensile values are averages with standard errors (n = 3, 3, 5 and 3 for the virgin, cycle 1, cycle 2 and cycle 3 polymers, respectively), and tensile curves are from single representative samples. b, Kinetics of depolymerization of 4S PA-8,DGX by methanolysis. Data points are from consecutive samples of individual reactions, and yields were determined by GC flame ionization detection with an internal standard. The diamine yield at the end of reaction (3.5 h) was determined by performing an identical reaction in deuterated solvents and using quantitative NMR with an internal standard. From left to right, the inset photos show the scaled chemical recycling reaction before reaction and after reaction and the resulting purified monomers.
