Poly[(R )-3-hydroxybutyrate)]/poly(styrene) blends compatibilized with the relevant block copolymer

摘要: A novel triblock copolymer PS-PHB-PS based on the microbial polyester Poly((R)-3-hydroxybutyrate)) (PHB) and poly- (styrene) (PS) was prepared to be used as compatibilizer for corresponding PHB/PS blends. It in a three-step procedure consisting of (i) transesterification reaction between ethylene glycol high-molecular-weight PHB, (ii) synthesis bromo-terminated PHB macroinitiator, (iii) atom transfer radical polymerization styrene initiated by PHB-based macroinitiator. Fourier transform infrared, gel perme- ation chromatography, 1 H-, 13 C-NMR spectroscopies were determine molecular structure and/or end-group functionalities at each step procedure. Although thermog- ravimetric analysis showed that block underwent stepwise thermal degradation had better stability than their respective homopolymers, differential scanning calo- rimetry displayed could not crystallize, thus generating total amorphous structure. Atomic force microscopy images indicated copoly- mer phase segregated well-defined morphological with nanodomain size � 40 nm. Contact angle meas- urements proved wettability properties those PS homo- polymers. Blends analyzed morphology good miscibility mor- phological features. Polymer blends exhibited lower crystallinity decreased stiffness which proportional amount content V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Chem 50: 5151-5160,