Synthesis, characterisation and properties of magnesium di(ε-caprolactamate)

Activated anionic ring-opening polymerization of ε-caprolactam with magnesium di(ε-caprolactamate) as initiator: effect of magnesium halides

“…11.2%), Br 35.0% (36.9%). CL 2 Mg-magnesium halide combined initiators were synthesized through the disproportionation of corresponding butyl magnesium halides by 1,4-dioxane followed by the addition of e-caprolactam to resulting Bu 2 Mg/MgX 2 mixture (X = Cl, Br, or I) as described in [27,28]. Then, solvent was evaporated under reduced pressure, and the resulting solid substance was dried in vacuum at 80-100°C for 3 h. As an example of typical procedure, the synthesis of MgCL 2 /MgI 2 is presented in detail.…”

“…Due to the fast reaction rate (equilibrium content of polymer [17] is achieved for 5-10 min [25] and even in less than 5 min under optimized polymerization conditions [26]), this initiator was successfully used in the reaction injection molding technology to produce block copolymers of e-caprolactam with polyethers [25]. Other magnesium salt of e-caprolactam, magnesium di(e-caprolactamate) (CL 2 Mg), has received insignificant attention as initiator of e-caprolactam polymerization due to its low activity in comparison with CLMgBr [4,5,[27][28][29]. These magnesium salts of e-caprolactam, in comparison with CLNa, are less sensitive to trace of water in the system [30] and also allow to synthesize polyamides with considerably higher thermal stability (especially in the case of using of CL 2 Mg) [5,29] and lower content of cyclic oligomers [18].…”