کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5178207 | 1502490 | 2017 | 7 صفحه PDF | دانلود رایگان |
- Stereocomplex mesophase in PLLA/PDLA blends was disclosed.
- Formation of stereocomplex mesophase was achieved just above Tg.
- Stereocomplex mesophase underwent melting upon heating.
- Homocrystals were induced from subsequent re-crystallization.
Stereocomplex mesophase is for the first time disclosed by annealing of 1:1 poly (l-lactide) (PLLA)/poly (d-lactide) (PDLA) blends just above glass transition temperature. Its structure is analogue to that of stereocomplex crystals, as a result of weak intermolecular interactions between PLLA and PDLA chains. In the limited temperature range formation of stereocomplex mesophase is enhanced with annealing temperatures; and its growth is well illustrated by Avrami formula with an index of about 3. Upon heating stereocomplex mesophase begins to melt at temperatures above 80 °C, followed by re-crystallization into homocrystals. The stereocomplex mesophase retards homocrystallization to some extent, since individual PLLA and PDLA chains need to be released from stereocomplex mesophase.
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Journal: Polymer - Volume 116, 5 May 2017, Pages 324-330