On the Effect of Alkyl End Group in Poly(ϵ-caprolactone) Oligomers: Preparation and Characterization

Poly(ϵ-caprolactone) (PCL) oligomers with α-hydroxyl-ω-alkyl end groups (alkyl =–CH2–[CH2–CH2]m–CH3, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10) were synthesized by ring-opening polymerization (ROP) of ϵ-caprolactone (CL) catalyzed by ammonium decamolybdate (NH4)8[Mo10O34] and using aliphatic primary alcohols as initiators (HO–CH2–[CH2–CH2]m–CH3, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10). The characterizations of the PCL oligomers were determined by MALDI-TOF, GPC, FT-IR, SAXS and 1H and 13C NMR. The effects of alkyl end groups on thermal properties of the PCL oligomers were analyzed by DSC and TGA.