Phosphazene-catalyzed ring-opening polymerization of ε-caprolactone: influence of solvents and initiators

Abstract

Metal-free ring-opening polymerization of ε-caprolactone was conducted using a relatively mild phosphazene base catalyst. The influence of solvents and protic initiators on the polymerization rate and control was demonstrated.

Synthesis and Characterization of Double Crystalline Cyclic Diblock Copolymers of Poly(ε‐caprolactone) and Poly(l(d)‐lactide) (c(PCL‐b‐ PL(D)LA))

“…Because the Huisgen 1,3‐dipolar cycloaddition reaction represents an efficient technique for the coupling of linear structures, well‐defined α‐azide, ω‐alkyne PCL‐ b ‐PL(D)LA linear copolymers have been prepared. By adapting the strategy developed by Hadjichristidis and co‐workers, those diblocks were obtained by sequential copolymerization of both ε‐caprolactone (CL) and lactide (LA) monomers from the 11‐azido‐1‐undecanol initiator while catalyzed by a P 2 ‐ t ‐Bu phosphazene base . Typically, the polymerization of CL is performed in THF ([CL] 0 ≈3 mol L −1 ) at r.t. for an initial monomer‐to‐initiator molar ratio ([CL] 0 /[I] 0 ) of 100.…”

“…By adapting the strategy developed by Hadjichristidis and co-workers, those diblocks were obtained by sequential copolymerization of both ε-caprolactone (CL) and lactide (LA) monomers from the 11-azido-1-undecanol initiator while catalyzed by a P 2 -t -Bu phosphazene base. [ 21 ] Typically, the polymerization of CL is performed in THF ([CL] 0 ≈3 mol L −1 ) at r.t. for an initial monomer-to-initiator molar ratio ([CL] 0 /[I] 0 ) of 100. After 4 h (Conv.…”

Extending the Scope of Benign and Thermally Stable Organocatalysts: Application of Dibenzoylmethane for the Bulk Copolymerization of l‐Lactide and ɛ‐Caprolactone

“…In that context, organocatalysts with low toxicity are of interest to achieve P(LA‐ co ‐CL)‐based materials. Attempts to use typical basic organocatalysts, such as phosphazenes, N ‐heterocycliccarbenes, or guanidine “superbases”, such as 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene did not enable to control the copolymerization of the two monomers. Acidic organocatalysts such as trifluoromethane sulfonic acid (TfOH) and (R)‐(−)‐1,1′‐binaphthyl‐2,2′‐diyl hydrogen phosphate (BPA) have also been used for this purpose .…”

Generating Triple Crystalline Superstructures in Melt Miscible PEO‐b‐PCL‐b‐PLLA Triblock Terpolymers by Controlling Thermal History and Sequential Crystallization

“…The triblock terpolymers under study were synthesized previously, as reported in ref. . The structure of the PEO‐ b ‐PCL‐ b ‐PLLA triblock terpolymers are presented in Figure .…”