聚(3-羟基丁酸酯)/聚氧化乙烯共混物非晶区相容性的固体核磁共振研究

SOLID-STATE ^(13)C-NMR STUDIES ON POLY(3-HYDROXYBUTYRATE)/POLY(ETHYLENE OXIDE) BLENDS: THE MISCIBILITY OF THE NONCRYSTALLINE REGIONS

用固体高分辨核磁共振碳谱方法研究了不同组成比的聚 (3 羟基丁酸酯 ) 聚氧化乙烯共混物的结晶度、非晶区的相容性和分子运动能力 .结果表明聚 (3 羟基丁酸酯 )的结晶度几乎不随组成比变化 ,而聚氧化乙烯的结晶度则随其在共混物中含量的降低而显著降低 .聚氧化乙烯的加入使得聚 (3 羟基丁酸酯 )非晶区的分子运动能力有所增强 .共混物的非晶区表现出一定的相容性 。

A series of poly(3-hydroxybutyrate) (PHB)/poly(ethylene oxide) (PEO) blends with different compositions were studied by solid-state high-resolution 13C-NMR spectroscopy.The crystallinity, 1H spin-spin relaxation time ( T 2 ) and 1H spin-lattice relaxation time in the rotating frame ( T 1ρ ) of PHB and PEO in the blends were measured.It was found that the crystallinity of PHB may keep almost constant over the whole composition range,while that of PEO decreased dramatically with decreasing PEO content. 1H T 2 of the noncrystalline region of PHB increases with the increase of PEO content,indicating that the mobility of the noncrystalline region of PHB has been enhanced. 1H T 1ρ s of the noncrystalline PHB and PEO become close to each other as composition of the blend changes.PHB and PEO are found to be partially miscible in the noncrystalline region of the blends.The miscibility depends on the composition.The highest miscibility of noncrystalline regions of PHB and PEO is achieved when the weight content of PEO is about 20%.