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Atomic force microscopy(AFM),wide-angle X-ray diffraction(WAXD) and differential scanning calorimetry are used to analyze the crystallization morphology and melting behavior of 4-arm PEO-b-PCL under high-pressure CO_2.It is demonstrated that CO_2 has certain effect on the melting and crystallization behavior of the samples.After crystallization under CO_2 at 4 MPa,spherulites with concentric ring-banded structure are formed which are composed of crystals with periodic thickness variation,and the band distance decreases with increasing treatment pressure.Due to the plasticization effect of CO_2,depression of the melting temperature is observed with sorption of CO_2 in polymers.
Atomic force microscopy (AFM), wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry are used to analyze the crystallization morphology and melting behavior of 4-arm PEO-b-PCL under high-pressure CO_2.It is characterized that CO_2 has some effect on the melting and crystallization behavior of the samples. After crystallization under CO_2 at 4 MPa, spherulites with concentric ring-banded structure are formed of crystals with periodic thickness variation, and the band distance decreases with increasing treatment pressure .Due to the plasticization effect of CO_2, depression of the melting temperature is observed with sorption of CO_2 in polymers.