Polyamide 6 modified with fullerenes, prepared via anionic polymerization of ε-caprolactam

epsilon-Caprolactam containing dispersed fullerenes (in amounts of 0.05, 0.1 or 0.3 wt. %) was subjected to anionic polymerization and then the products obtained were granulated. Investigation of the polymerization kinetics, based on temperature measurements, as well as the investigation of crystallization of polymer obtained (Fig. 1 and 2) showed that fullerenes (in the studied concentration range) did not inhibit the polymerization process. However, they slightly slowed down the crystallization of polyamide 6 and decreased the crystallization degree (DSC results, Fig. 2). The structure of crystalline phase was characterized using WAXS method (Fig. 3 and 4). TGA investigations showed also that fullerene acted as thermal stabilizer of PA 6 (Fig. 5 and 6, Table 2). According to the results of DMTA measurements (Fig. 7 and 8) in the whole range of temperature studied (from -90 to + 240 degrees C) the values of storage modulus (E') of PA 6 modified with fullerenes were higher than those of unmodified PA 6. Modification of PA 6 increases the stress at break and Young's modulus while elongation at break and impact strength decrease a bit (Table 3). The results of the product's estimation show that optimal content of fullerenes is 0.1 wt. %.