Kinetics of the Anionic Polymerization of [epsilon]-Caprolactam From an Isocyanate Bearing Polystyrene

摘要

This work aims to systematically study a reactive extrusion process for the synthesis of graft copolymers with polystyrene (PS) as backbone and polyamide 6 (PA6) as grafts. The underlying chemistry relies on the use of a random copolymer of styrene (St) and 3-isopropenyl-α,α-dimethylbenzene isocyanate (TMI), PS-co-TMI, to activate the polymerization of ε-caprolactam (CL) using sodium ε-caprolactam (NaCL) as a catalyst. To obtain sufficiently high polymerization rate and monomer conversion, the following conditions should be met simultaneously: polymerization temperature higher than 220° C, TMI content in PS-co-TMI higher than 2 wt%, and the molar ratio between the isocyanate group in PS-co-TMI and NaCL smaller than 3. Moreover, feeding mode has a little effect on the CL conversion and the composition of PS-g-PA6 but has a strong effect on the polymerization induction time. [PUBLICATION ABSTRACT]