How the Complex Interplay between Different Blocks Determines the Isothermal Crystallization Kinetics of Triple-Crystalline PEO-b-PCL-b-PLLA Triblock Terpolymers
How the Complex Interplay between Different Blocks Determines the Isothermal Crystallization Kinetics of Triple-Crystalline PEO-b-PCL-b-PLLA Triblock Terpolymers
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DOI：
10.1021/acs.macromol.7b02148
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发表时间：
2017-12
期刊：
影响因子：
5.5
通讯作者：
Jordana K. Palacios;Junpeng Zhao;N. Hadjichristidis;A. Müller
中科院分区：
文献类型：
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作者：
Jordana K. Palacios;Junpeng Zhao;N. Hadjichristidis;A. Müller
PEO-b-PCL-b-PLLA三嵌段三元共聚物是令人着迷的三晶材料。本文首次用差示扫描量热法(DSC)研究了这些三元共聚物的等温结晶动力学，并与类似的PCL-b-PLLA两嵌段共聚物以及PLLA、PCL和PEO均聚物进行了比较。结果得到了SAXS/WAXS同步加速器现场实验的补充。采用一步、两步和三步结晶方案研究了块体的结晶动力学。在PLLA嵌段结晶温度下，PCL和PEO熔融链均对PLLA嵌段结晶有较强的增塑作用，且PLLA嵌段在三元共聚物中的总结晶速率高于PLLA-b-PCL两嵌段共聚物。在PCL嵌段的情况下，在PLLA完全结晶(两步结晶)之后进行结晶。观察到了先前形成的PLLA晶体的成核效应。..。
PEO-b-PCL-b-PLLA triblock terpolymers are fascinating triple-crystalline materials. In this work, the isothermal crystallization kinetics of these terpolymers evaluated by differential scanning calorimetry (DSC) is presented for the first time and compared to analogous PCL-b-PLLA diblock copolymers and to PLLA, PCL, and PEO homopolymers. The results are complemented by in situ SAXS/WAXS synchrotron experiments. One-, two-, and three-step crystallization protocols were employed to study the crystallization kinetics of the blocks. At PLLA block crystallization temperatures, both PCL and PEO molten chains caused a strong plasticizing effect on the PLLA block crystallization, and the overall crystallization rate of the PLLA block in the terpolymers was higher than that in the PLLA-b-PCL diblock copolymers. In the case of the PCL block, the crystallization was followed after PLLA was fully crystallized (two-step crystallization). A nucleating effect induced by the previously formed PLLA crystals was observed. ...