Investigation of initiator metal efficiency in the ring-opening polymerization of lactones: an experimental and computational study
Küçük Resim Yok
Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Wiley
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Poly(delta-valerolactone) (PVL) was synthesized by ring-opening polymerization (ROP), employing tin(II) acetate (SnAcet(2)), lead(II) acetate trihydrate (PbAcet(2)center dot 3H(2)O) and cadmium(II) acetate dihydrate (CdAcet(2)center dot 2H(2)O) complexes as initiators without any co-initiator. The highest molecular weight PVL (45 438 g mol(-1), 91% yield) was obtained with CdAcet(2)center dot 2H(2)O. Characterization of the synthesized products was performed by FTIR, H-1 NMR, C-13 NMR, gel permeation chromatography (GPC), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS), TGA and DSC. Electrostatic data (natural bond orbital and Hirshfeld) and lowest unoccupied molecular orbital (LUMO) of the initiators were obtained by using several density functional theory methods (B3LYP, omega B97X-D, PBEPBE, BPV86, HSEH1PBE, MPW1PW91, M06 and M062X). In addition, the initiation stage of the ROP mechanism of delta-valerolactone with these metal acetate complexes was investigated at the omega B97X-D level with a mixed basis set. It was computationally determined that the most effective initiator was also CdAcet(2). The molecular weight variation of PVLs synthesized with these initiators can be associated with the combined evaluation of atomic charge, LUMO and orbital overlap analyses. The computationally obtained reaction barriers for the initiators support this idea, also. In addition, toxicity tests carried out for PVLs synthesized with acetate complexes containing Sn, Cd and Pb revealed that the Sn and Cd complexes do not have a toxic effect on cell viability at some dilution rates. (C) 2021 Society of Industrial Chemistry.
Açıklama
Anahtar Kelimeler
poly(delta-valerolactone), ring-opening polymerization (ROP), density functional theory, metal acetates, biodegradable polymers, Hirshfeld, Effective Core Potentials, Epsilon-Caprolactone, L-Lactide, Delta-Valerolactone, Basis-Sets, Molecular Calculations, Cyclic Esters, Zinc, Acetate, Complexes
Kaynak
Polymer International
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
71
Sayı
7
