Kinetics and thermodynamics of l-lactide polymerization studied by differential scanning calorimetry. (January 2015)

• Record Type: Journal Article
• Authors: Sedush, Nikita G.; Chvalun, Sergei N.
• Is Part Of: European polymer journal. Volume 62(2015:Jan.)
• Page Start: 198
• Page End: 203
• Publication Date: 2015-01
• Subjects: Polylactide -- Biodegradable -- Kinetics curves -- Thermodynamics of reaction -- Differential scanning calorimetry; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2014.11.038
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Method of differential scanning calorimetry was found to be effective for studying polymerization of lactide. Kinetics of l -lactide polymerization with stannous octoate was studied at 180–220 °C. Enthalpy of l -lactide polymerization was found to be Δ H = −19 ± 0.5 kJ mol −1 . Activation energy, preexponential constant and entropy of l -lactide polymerization were calculated. Abstract: Kinetics of l -lactide polymerization was studied by differential scanning calorimetry in isothermal mode at various temperatures and catalyst concentrations. The enthalpy of l -lactide polymerization measured directly in DSC cell was found to be Δ H = −19 ± 0.5 kJ mol −1 . Kinetic curves of l -lactide polymerization and propagation rate constants were determined for polymerization with stannous octoate at concentrations 200–1100 ppm at temperatures 180, 190, 200 and 220 °C. Using model or reversible polymerization the following kinetic and thermodynamic parameters were calculated: activation energy Ea = 50 ± 5 kJ mol −1, preexponential constant ln A = 18 ± 1, entropy of polymerization Δ S = −12 ± 1 J mol −1 K −1 .