Enhanced thermal stability of poly(1,4-dioxan-2-one) in melt by adding a chelator

Thermal stability of poly(p-dioxanone) (PPDO) was investigated isothermally and non-isothermally under air atmosphere using thermogravimetry (TG). The addition of 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (PMBP) could enhance successfully the thermal stability of PPDO compared with those of as-prepared and purified PPDO at temperature below about 230 °C. The activation energies for thermal degradation (ΔEtd) were evaluated at different weight loss values from TG data using the procedure recommended by MacCallum et al. The ΔEtd values of as-prepared PPDO, purified PPDO and PPDO containing 1.0 wt% PMBP were in the ranges of 20-50, 35-60, and 56-88 kJ mol−1, respectively, when they were evaluated at weight loss values of 10-80%. The remaining weights increase with the amounts of PMBP added up to 1.5 wt%. The mechanism for the enhanced thermal stability of PPDO was discussed.