Monodisperse oligo(δ-valerolactones) and oligo( -caprolactones) with docosyl (C) end-groups

Linear aliphatic oligoesters derived from δ-valerolactone (VL) and -caprolactone (CL) were synthesised by ring-opening polymerisation (ROP) using 1-docosanol (C 22 H 45 OH, C 22 OH) and aluminum isopropoxide [Al(O i Pr) 3 ] as initiator and catalyst, respectively. Monodisperse species such as monomers, dimers, trimers, and tetramers with terminal groups α-hydroxyl-ω-docosyl (C 22 )-(C 22 VL and C 22 CL) were isolated by flash column chromatography (FCC). Characterisation by MALDI-TOF and 1 H NMR spectroscopy corroborated the chemical nature of the samples. This work represents the first time in the literature that monodisperse species derived from VL are isolated. The thermal properties of C 22 VL and C 22 VL showed a pattern suggesting that the crystallinity was proportional to the length of the chain. The presence of C 22 groups promoted the nucleation of the crystalline domain in the monomers (C 22 VL 1 and C 22 CL 1 ), increasing their respective melting temperatures ( T m ) relative to those of their non-monodisperse oligomers (C 22 PVL or C 22 PCL). Finally, monodisperse species and non-monodisperse oligomers were analysed by POM. Two different families of monodisperse oligoesters with α-hydroxyl-ω-docosyl (C 22 ) terminal groups [oligo(δ-valerolactone) and oligo(ϵ-caprolactone)] were isolated by flash column chromatography (FCC).