Fast-activated anionic polymerization of -caprolactam in suspension, 1

The fast-activated anionic polymerization of ε-caprolactam has been performed in suspension in order not only to efficiently dissipate the heat of polymerization, but also to directly synthesize powdered polyamide 6. The continuous phase of the system is composed of polyisobutene oils: five fractions, different in their molecular weights and viscosities, have been used and thoroughly studied in terms of their influence on polymerization yield, as well as on polyamide 6 chemical and physical properties, and on shape and size of the polymer particles. The above characterizations have been performed on samples synthesized varying the weight ratio between the suspending medium and the droplets made of monomer, initiator (sodium caprolactamate) and ultra-fast activator (cyclohexyl carbamoyl caprolactam). Sample LR14 (PIB 200, CL wt.-% = 6.7).