Kinetics of D,L–Lactide Polymerization Initiated with Zirconium Acetylacetonate

Autor: Nikita G. Sedush, Sergei N. Chvalun, Petr V. Dmitryakov, Kirill T. Kalinin
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: ChemistryOpen, Vol 9, Iss 10, Pp 1027-1032 (2020)
ChemistryOpen
ISSN: 2191-1363
Popis: The kinetic of D,L‐lactide polymerization in presence of biocompatible zirconium acetylacetonate initiator was studied by differential scanning calorimetry in isothermal mode at various temperatures and initiator concentrations. The enthalpy of D,L‐lactide polymerization measured directly in DSC cell was found to be ΔH=−17.8±1.4 kJ mol−1. Kinetic curves of D,L‐lactide polymerization and propagation rate constants were determined for polymerization with zirconium acetylacetonate at concentrations of 250–1000 ppm and temperature of 160–220 °C. Using model or reversible polymerization the following kinetic and thermodynamic parameters were calculated: activation energy Ea=44.51±5.35 kJ mol−1, preexponential constant lnA=15.47±1.38, entropy of polymerization ΔS=−25.14 J mol−1 K−1. The effect of reaction conditions on the molecular weight of poly(D,L‐lactide) was shown.
Zirconium acetylacetonate is a biocompatible initiator, which demonstrates high activity in the bulk polymerization of lactide. Polylactide with molecular weight up to 187 kDa and conversion of 96 % can be synthesized in less than an hour. The effect of temperature and initiator concentration on kinetics of D,L‐lactide polymerization was studied by differential scanning calorimetry.
Databáze: OpenAIRE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje