Abstract: PHBV decreased after incorporation ofMgO,meanwhile the densi- ty of spherulites increased.The onset thermal degradation temperature of part PHBV matrix in PHBV/ MgOcomposites increased more than 140℃ that of neat PHBVBased on DSC determination,the ef fects of MgOon the crystallization and thermal behavior were considered probably due to the reaction be tween PHBV and MgO occurred at molten state.

Key words: poly(β-hydroxybutyrate-co-B-hydroxyvalerate);magnesium oxide;crystallization, melting thermal degradation