Hydrothermal aging behavior of poly(butylene fumarate)(PBF) has been systematically studied in this article in order to evaluate the feasibility of PBF to be used as a biodegradable material.The variation of mechanical properties

thermal properties

molecular weight and chemical groups with the progress of aging has been investigated in detail by GPC

mechanical tests

DSC and ATR-FTIR.The results show that PBF possesses good aging resistance under natural condition.The mechanical properties vary little upon aging at 30 ℃ for 40 days.But the aging resistance of PBF decreases sharply with increasing temperature and the temperature greatly influences the aging behavior.With increasing the temperature to 60 ℃

the sample ages faster

and Mn decreases by about 50% upon degradation for 20 days.Further increasing temperature to 80 ℃

the sample ages very quickly

and Mn decreases to about 13% upon degradation for 5 days.No obvious change in content of C=C double bonds and carboxyl index has been observed.The presence of C=C double bonds is not the main cause of the aging of PBF and the aging mechanism is the plasticization and swelling of water

hydrolyzation of ester bonds

breakdown of polymer chains

and decrease of molecular weight.Obvious increase in crystallization temperature (3~18 K)

melting temperature (2~4 K)

and enthalpy (21%~55%) of PBF upon aging can be found

arising from the chemical crystallization.