Influence of thermal treatment, molecular weight and orientation on the mechanical properties of polyamide‐6

Undrawn and drawn polyamide‐6 bristles were annealed in vacuum at different temperatures between 80 and 228°C. It was found that at higher temperatures (above 140 to 160 °C) besides an increase of the crystallinity an additional solid state postcondensation proceeds, leading to a narrower molecular weight distribution. These changes in crystallinity, molecular weight and its distribution result in improved mechanical properties. The influence of annealing on the orientation as well as its relation to the mechanical behaviour are discussed.