The mechanism of caprolactam polymerization catalyzed by anhydrous phosphoric acid

Cationic Ring Opening polymerization of ε-caprolactam by a Montmorillonite Clay Catalyst

“…The cationic polymerization of ε-caprolactam and its reaction mechanism has been studied for many years in the presence of cationic initiators [6][7][8][9][10][11]. Various strong protonic acids able to promote the polymerization of ε-caprolactam have been reported [12][13][14][15][16][17][18]. The separation of the initiators from the polymer is not always possible.…”

“…The novelty of this work is to propose a greener and more sustainable route in order to replace the hazardous acidic catalysts such as: H3PO4 [12,17] and HCl [18] by modified clay of our region (Maghnite-H + ) for the synthesis of polyamide 6, a new, non-toxic cationic catalyst for heterocyclic monomers [23], which is widely available, constitutes low costs and has excellent properties make it the subject of several research. The obtained results will be compared with those obtained previously with strong acids.…”

Organic-acid mediated bulk polymerization of ε-caprolactam and its copolymerization with ε-caprolactone

“…Many studies have shown the effectiveness of organic catalysts to promote ROP of lactones such as: valerolactone, caprolactone or more recently ethylene brassylate and cyclic carbonates to synthesize well‐defined polymers. However, there have been only a few studies utilizing organic catalysts in ROP of lactams . Some years ago, the polymerization of ε‐CLa at temperatures < 200 °C, below T m of PA6, was reported by the use of strong organic base catalysts such as poly(aminophosphazenes) and protophosphatranes .…”