An effective way to improve the thermostability of poly(β-hydroxybutyrate)(PHB) was developed．Maleic anhydride (MAH) was grafted onto PHB by 60Coγcharacterize radiation．1H-NMR

13C-NMR．TGA

DSC and XRD were used to characterize the radiated samples The results of beth 1H-NMR and 13C-NMR are consistent with the successful grafting of MAH monomem onto PHB molecules．The TGA measurements demonstrated that the thennal stability of grafted PHB was measurably improved with the introduction of MAH groups．The 5％ weight loss temporatureof the grafted PHB with a graft degree of 0.52％ was enhanced by 36 K．These significant results suggest that wide commercial application of PHB may be possible The DSC results showed beth the melting temperature and crystallization temperature of the grafting products were decreased Moreover．Lhe erystallinity of the grafted PHB was decreased with the introduction of MAH groups

and the hydmphilie pmporty was impmved.