Premium
Morphology and Melt Crystallization of PCL‐PEG Diblock Copolymers
Author(s) -
Xu Ying,
He Yong,
Wei Jia,
Fan Zhongyong,
Li Suming
Publication year - 2008
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200800137
Subject(s) - spherulite (polymer physics) , copolymer , crystallization , materials science , morphology (biology) , polymer chemistry , isothermal process , peg ratio , chemical engineering , composite material , polymer , thermodynamics , physics , finance , biology , economics , genetics , engineering
ROP of PCL was realized in the presence of mPEG with $\overline M _{\rm n}$ = 5 000, using Zn(La) 2 as a catalyst. The resulting diblock copolymers with molar ratios of the CL/EO repeat units from 0.2–5.0 were characterized by DSC, WAXD, SEC, and 1 H NMR. Melt crystallization was studied and analyzed with the Avrami equation. The spherulite growth rate G was determined at different crystallization temperatures. The G values were found to range between those of mPEG and PCL homopolymers. The morphology of an isothermally crystallized sample with CL/EO = 0.5 was examined. Spherulites with PCL embedded in PEG were observed, in contrast to concentric spherulites reported in the literature.