Differences and similarities in the thermooxidative degradation of polyamide 46 and 66

摘要: Abstract A comparison is made between the thermooxidative degradation of polyamide 46 (PA46) and 66 (PA66), using oven ageing, oxygen uptake viscosity measurements on two polymers. Model experiments were used to determine mechanism PA46. Although a chemical basis it expected that PA46 would be less stable than PA66, opposite found. The time until tensile strength becomes 50% its initial value twice as long for unstabilized compared with PA66 at 145 °C. It shown surface phenomenon thus diffusion limited. more due lower permeability, probably caused by higher crystallinity density amorphous phase.