標題: Self-Assembly structures through competitive interactions of miscible crystalline-amorphous diblock copolymer/homopolymer blends
作者: Lin, I-Hong
Kuo, Shiao-Wei
Chang, Feng-Chih
應用化學系
Department of Applied Chemistry
關鍵字: Self-assembly;Block copolymer;Hydrogen bonding
公開日期: 20-Oct-2009
摘要: A series of miscible crystalline-amorphous diblock copolymers, (poly(epsilon-caprolactone)-b-(vinyl phenol), PCL-b-PVPh) were prepared through sequential ring-opening and controlled living free radical (nitroxide-mediated) polymerizations and then blended with poly(vinyl pyrrolidone) (PVP) homopolymer. Specific interactions, miscibility, and self-assembly morphologies mediated by hydrogen bonding interactions of this new A-B/C type blend, were investigated in detail. Micro-phase separation of these miscible PCL-b-PVPh diblock copolymers occurs by blending with PVP through competitive hydrogen bonding interaction in this A-B/C blend. FTIR, XRD, and DSC analyses provide positive evidences that the carbonyl group of PVP is a significantly stronger hydrogen bond acceptor than PCL, thus the PCL block is excluded from the PVPh/PVP miscible phase to form self-assembly structure. (13)C CP/MAS solid-state NMR spectra provide additional evidence confirming that micro-phase separation occurs in the blend system because of the presence of more than two T(1p)(H) values for this A-B/C blend system. According to the result of the FTIR and SAXS results, the smaller molecular weight system contains a greater fraction of the hydrogen-bonded carbonyl group, cause indirectly the high degree of phase separation among these blends. In addition, the SAXS profiles possess a sharp primary peak and highly long range ordered reflections q/q* ratios of 1:2:3 at lower PVP content, an indication of the lamellar structure in the blend which is consistent with TEM image. The phase behavior and morphology shifts from lamellar to cylinder structure with further increase in the PVP content. (C) 2009 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.polymer.2009.09.012
http://hdl.handle.net/11536/6558
ISSN: 0032-3861
DOI: 10.1016/j.polymer.2009.09.012
期刊: POLYMER
Volume: 50
Issue: 22
起始頁: 5276
結束頁: 5287
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