Comonomer compositional distribution and thermal and morphological characteristics of bacterial poly(3-hydroxybutyrate-co-3-hydroxyvalerate)s with high 3-hydroxyvalerate content.
Comonomer compositional distribution and thermal and morphological characteristics of bacterial poly(3-hydroxybutyrate-co-3-hydroxyvalerate)s with high 3-hydroxyvalerate content.
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DOI：
10.1021/bm010128o
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发表时间：
2001-10
影响因子：
6.2
通讯作者：
Yi Wang;Shino Yamada;N. Asakawa;Tsuneo Yamane;N. Yoshie;Yoshio Inoue
中科院分区：
文献类型：
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作者：
Yi Wang;Shino Yamada;N. Asakawa;Tsuneo Yamane;N. Yoshie;Yoshio Inoue
研究了细菌合成的聚(3-羟基丁酸酯-3-羟基戊酸酯)[P(3HB-co-3HV)][P(3HB-co-3HV)]的共聚单体组成分布、热性能和形态特征。通过改变氯仿/正庚烷混合溶剂的溶剂/非溶剂体积比，将这些样品分成许多3HV含量相差很大的馏分。本文研究的细菌P(3HB-co-3HV)样品具有广泛的共聚单体组成分布。3HV含量低于60mol%的P((3HB-co-3HV)S)与3HV含量高于80mol%的P((3HB-co-3HV))的分级析出趋势相反。用DSC、WAXD和固态(13)C-核磁共振研究了细菌聚(3-羟基丁酸酯)[P(3HB)]和一系列组成较好的P(3HB-co-3HV)样品的3HV含量与热性能和晶体结构的关系。结果表明，3HV含量低于约47mol%的P(3HB-co-3HV)样品形成了以3HV单元为组成的P(3HB)均聚型晶格，3HV含量大于约52mol%的P(3HV)样品形成了含有3HB单元的P(3HV)均聚型晶格。因此，P(3HB-co-3HV)S在很窄的3HV含量范围内表现出晶体结构的变化。
The comonomer compositional distribution and thermal and morphological characteristics were investigated for five bacterially synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] samples with 3HV content of 45, 49, 70, 80, and 96 mol %. All these samples were fractionated into many fractions with widely different 3HV content by changing solvent/nonsolvent volume ratio of chloroform/n-heptane mixtures. Bacterial P(3HB-co-3HV) samples investigated in this study were found to have broad comonomer compositional distribution. The tendencies of the fractional precipitation of the P((3HB-co-3HV)s with 3HV content lower than 60 mol % and those with 3HV higher than 80 mol % were found to be contrary. The 3HV content dependences of the thermal properties and crystalline structures were investigated for bacterial poly(3-hydroxybutyrate) [P(3HB)] and a series of compositionally well-fractionated P(3HB-co-3HV) samples with 3HV content ranged from 14 to 98 mol % by DSC, WAXD, and solid-state (13)C NMR. It was found that P(3HB-co-3HV) samples with 3HV content lower than about 47 mol % form the crystalline lattice having the P(3HB) homopolymer type lattice including the 3HV unit as the crystal constituent, and those with a 3HV content higher than about 52 mol % form the crystalline lattice having the P(3HV) homopolymer type lattice including the 3HB units. Thus, P(3HB-co-3HV)s show the crystalline structural change in a very narrow range of 3HV content.