Thermodynamics and kinetics of Novozym 435 catalyzed ring-opening polymerization of 1,4-dioxan-2-one

• Novozym 435 catalyzed ROP of PDO exhibit equilibrium behavior.
• ΔHp and ΔSp0 were −19 kJ mol−1 and −66 J K−1 mol−1, respectively.
• The ROP kinetic of PDO was first order with the monomer concentration.
• Eapp of ROP of PDO was 45.3 kJ mol−1.

In this paper thermodynamics and kinetics of bulk ring-opening polymerization (ROP) of 1,4-dioxan-2-one (PDO) catalyzed by Novozym 435 were investigated. Results showed that the polymerization reached equilibrium after 12 h at 60 °C in the presence of 5 wt% Novozym 435 (based on PDO). The calculated thermodynamic parameters, enthalpy and standard entropy of the polymerization, are −19 kJ mol−1 and −66 J K−1 mol−1, respectively. The kinetic plot of ln{([M]0 − [M]e)/([M]t − [M]e)} vs time is linear, indicating that the polymerization is first order with respect to the monomer concentration. The calculated apparent activation energy (Eapp) is 45.3 kJ mol−1, which is lower than that using Sn(Oct)2 and La(OiPr)3 as catalysts. According to 1H NMR and GPC analysis, the ROP of PDO with Novozym 435 catalyzed follows monomer activated mechanism.

The thermodynamics and kinetics of Novozym 435 catalyzed the ROP of 1,4-dioxan-2-one (PDO) were investigated. The calculated enthalpy and standard entropy of the polymerization were −19 kJ mol−1 and −66 J K−1 mol−1, respectively. The kinetic plot of ln{([M]0 − [M]e)/([M]t − [M]e)} vs time was a linear indicating that Novozym 435 catalyzed the polymerization was first order with respect to the monomer concentration. Novozym 435 catalyzed the ROP of PDO also follows monomer activated mechanism.Figure optionsDownload as PowerPoint slide