HYDROGEN BONDING, MISCIBILITY, AND THERMAL BEHAVIOR OF BIODEGRADABLE POLYMER BLENDS OF POLY(3-HYDROXYBUTYRATE) AND POLY(4-VINYLPHENOL)

摘要

@@The hydrogen bonding interactions, miscibility, and crystallinity of biodegradable polymer poly(3hydroxybutyrate) (PHB) blended with poly(4vinylphenol) (PVPh) were studied on the casting films as a function of the blend composition wpvph and temperature by using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and wide angle X-ray diffraction (WAXD). Over the whole composition range of PHB/PVPh blends, all DSC thermograms apparently exhibit a single T_g, and these values increase with wrvn, indicating that the PHB is miscible with PVPh in the melt state or the amorphous part of PHB is miscible with PVPh when PHB is crystallized in the blend. The intermolecular hydrogen bondings between the C=O groups of PHB and the OH groups of PVPh (designed as inter) were explored not only in C=O stretching vibration region but also in OH stretching vibration region. For PHB, the intramolecular hydrogen bonding interactions between the C=O groups and CH_3 groups of PHB (designed as intra) exists in lamellar structure of crystal part. The competing hydrogen bonding interactions between intra and inter is a crucial physical factor underlying the basic physics of the blends with respect to ordering via crystallization, miscibility, and even phase separation.