A novel initiating system for ring‐opening polymerization of ε‐caprolactone: Synthesis of triarm star‐shaped poly(ε‐caprolactone)

Abstract

ABSTRACT:The rare earth compound, scandium trifluoromethanesulfonate [Sc(OTf) 3 ], has been used as a water-tolerant catalyst for the synthesis of star-shaped poly(e-caprolactone)s (SPCLs) with trimethylol propane as trifunctional initiator in solvent at 40 C. Triarm SPCLs have been successfully prepared. The molar mass of SPCLs were determined by end-group 1 H NMR analyses, which could be well controlled by the molar ratio of the monomer to the initiator, and were independent of the amount of Sc(OTf) 3 used. Differential scanning calorimetry analyses suggested that the maximal melting point, the cold crystallization temperature, and the degree of crystallinities of SPCLs increased with the increasing of the molar mass and were lower than the linear poly (e-caprolactone) (LPCL) with similar molar mass. Furthermore, polarized optical microscopy indicated that LPCL showed fast crystallization rate and good spherulitic morphology with apparent Maltese cross pattern, whereas SPCLs exhibit much lower crystallization rate and poor spherulitic morphology.

Fully degradable antibacterial poly(ester‐phosphoester)s by ring‐opening polymerization, “click” chemistry, and quaternization

“…ROP of cyclic phosphates is a more common approach with catalysts, such as Al(OiPr) 3 and Sn(Oct) 2 . Our research group has been working on the study of rare‐earth catalysts, and developed a series of effective catalysts for the ROP of lactones, lactides, and cyclic carbonates . Recently, we reported the ring‐opening copolymerization of 2‐methoxy‐2‐oxo‐1,3,2‐dioxaphospholane (methyl ethylene phosphate, MEP) or 2‐(2‐chloroethoxy)‐2‐oxo‐1,3,2‐dioxaphospholane (CEP) with CL catalyzed by lanthanum tris(2,6‐di‐tert‐butyl‐4‐methylphenolate)s (La(DBMP) 3 ), to give poly(ester‐phosphoester) random copolymers with high molecular weight and moderate molecular weight distribution.…”

Poly(ester-co-ether) from ring-opening copolymerisation of sustainable 2-methyltetrahydrofuran with β-butyrolactone

“…As Lewis acids, rare-earth triflates (RE(OTf ) 3 ) are highly active catalysts for cationic ROP of lactones and cyclic ethers. 26,[28][29][30][31][32][33][34][35] From this point of view, it is possible to synthesize novel 2-MeTHF-based polymeric materials through the cationic ring-opening copolymerization of 2-MeTHF with BBL catalysed by (RE(OTf ) 3 ).…”

Heteroleptic lanthanide amide complexes bearing carbon-bridged bis(phenolate) ligands: synthesis, structure and their application in the polymerization of ε-caprolactone

“…One possible polymerization mechanism is via coordination/insertion (shown in Scheme 4), which is similar to the literature. 45,46 Experimental section HN(TMS) 2 (TMS ¼ SiMe 3 ), 3-caprolactone, and n BuLi are commercially available. All manipulations were performed under pure nitrogen with a rigorous exclusion of air and moisture using Schlenk techniques and a glovebox.…”