COMPATIBILITY AND SPECIFIC INTERACTIONS I N POLY(BETA-HYDROXYBUTYRATE) AND POLY(P-VINYLPHENOL) BLENDS

The miscibility and specific interactions in poly (beta-hydroxybutyrat e) (PHB)/poly(p-vinylphenol) (PVPh) blends were studied by differentia l scanning calorimetry(DSC) , fourier transform infrared(FTIR) spectro meter and high resolution solid state C-13 NMR, A single composition-d ependent glass transition temperatures were obtained by DSC which indi cate the blends of PHB/PVPh were miscible in the melt state, The exper imental glass transition temperatures were fitted quite well with thos e obtained from Couchman-Karasz equation. The FTIR study shows that th e strong intermolecular hydrogen bonding exists in blends of PHB with strong proton acceptor and PVPh with strong proton donor and is the or igin of its compatibility. The CPMAS C-13 NMR spectra also show that t he strong hydrogen bonding exists in PHB/PVPh blends. From the T-1 rho (H) relaxation time it follows that the blends of PHB/PVPh(40/60, 20/8 0) studied are completely homogeneous on the scale of about 3.2 nm.