Investigation of Poly(lactide) Stereocomplexes: 3-Armed Poly(L-lactide) Blended with Linear and 3-Armed Enantiomers
Investigation of Poly(lactide) Stereocomplexes: 3-Armed Poly(L-lactide) Blended with Linear and 3-Armed Enantiomers
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聚（丙交酯）立体复合物的研究：与线性和 3 臂对映体混合的 3 臂聚（L-丙交酯）
DOI：
10.1021/jp303402j
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发表时间：
2012-08-23
影响因子：
3.3
通讯作者：
Chen, Xuesi
中科院分区：
文献类型：
--
作者：
Shao, Jun;Sun, Jingru;Chen, Xuesi
将三臂聚乳酸（3 PLLA）与线型聚乳酸（PDLA）以及对映体3 PLA之间进行溶液共混，得到了立体复合聚乳酸（sc-PLA）。差示扫描量热法和广角X-射线衍射结果表明，外消旋微晶优先产生在所有的二元共混物。聚乳酸的结构、组成和分子量不同，外消旋微晶的熔融温度和熔融焓也不同。通过本研究，中分子量二元共混物获得了较高的熔融温度，外消旋微晶的最高熔融温度达到246 ℃，是迄今为止报道的最高值。在分子量相近的共混物中（或线性PLA与3 PLA对映体的各分支相似），随着3 PLA组成的增加，相分离分子量逐渐减小（M-线性/I-分支共混物M-线性/3-分支共混物> M 3-分支/3-分支共混物）。3 PLLA/PDLA和3 PLLA/3 PDLA共混物的热性能和相行为因3 PLA和线性PLA的结构差异而不同。这些混合物的热性质及其变化为其工业应用提供了基础数据。
Stereocomplex poly(lactide)s (sc-PLAs) were obtained from solution blending of 3-armed poly(L-lactide) (3PLLA) and linear poly(D-lactide) (PDLA) and between enantiomeric 3PLAs. Differential scanning calorimetry and wide-angle X-ray diffraction results indicated that racemic crystallites were preferentially produced in all the binary blends. The melting temperature and fusion enthalpy of racemic crystallites were remarkably different through varying the structure, constituent, and molecular weight of PLA. Through this investigation, higher melting temperatures were obtained in the middle molecular weight binary blends, and the highest melt temperature of racemic Crystallites reached to 246 degrees C, it was the highest reported value until now. In similar molecular weight blends (or the linear PLA was similar to each branch of 3PLA enantiomers), with the composition of 3PLA increasing, the phase separation molecular weight decreased gradually (M-linear/Imear blends Mlinear/3-armed blends > M3-armed/3-armed blends). The structure distinction between 3PLA and linear PLA induced different thermal properties and phase behaviors of the 3PLLA/PDLA and 3PLLA/3PDLA blends. The thermal properties of these mixtures and its variations provided basic data for their industrial applications.