The Effect of Trifluoroacetic Anhydride on Poly(ϵ-caprolactone) (PCL) Oligomers

Trifluoroacetic anhydride (TFAA) and asymmetric telechelic α-hydroxyl-ω-(carboxyl acid) poly(ϵ-caprolactone) (HA-PCL) were used to obtain in situ α-trifluoroacetate-ω-trifluoroacetanhydride poly(ϵ-caprolactone) (TF-PCL). After reaction, the polymer was characterized by 1H and 13C NMR, MALDI-TOF, FT-IR, DSC, and TGA. Under the influence of TF-PCL and its terminal groups, parasitic reactions as transesterifications and inter- and intramolecular condensation are favored. The reactivity of ω-trifluoroacetanhydride end group with α-hydroxyl-ω-methoxy polyethyleneglycol (MPEG) was used for the synthesis of poly(ϵ-caprolactone-b-ethylene glycol) (PCL-b-PEG) diblock copolymer.