Crystalline/amorphous triblock copolymers PMMA-b-PHBV-b-PMMA with bacterial polyester poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as crystalline component and polymethyl methacrylate (PMMA) as amorphous component were prepared via atom transfer radical polymerization (ATRP).Molecular weight and molecular weight distribution

molecular structure have been characterized by gel permeation chromatography (GPC)

together with Fourier transform infrared spectroscopy (FTIR)

and 1H nuclear magnetic resonance (1H-NMR).The morphology of the triblock copolymers was characterized by polarizing optical microscopy (POM).Thermal stabilities have been studied by thermal gravimetric method (TG)

and the degradation activation energy was calculated by Horowitz-Metzger method.Results showed that the maximum yield of triblock copolymer was 92.39%.The crystalline morphology of neat PHBV shows obvious banded spherulites.With PMMA content increase

the crystalline morphology of triblock copolymers changes from banded pattern to radial pattern

with a decreasing radius of spherulites.When the molar ratios of PMMA and PHBV is 10:1

the edge of spherulites becomes unclear.The TG analysis revealed that T0

T5%

Tmax of triblock copolymer with the molar ratios of PMMA and PHBV between 2:1 and 8:1 were raised to 25

15 and 40℃

and the degradation activation energy of triblock copolymers may decrease from 428.25 kJ mol-1 to 169.83 kJ mol-1.