Higher-order crystalline structures of poly(oxyethylene) in poly(D,L-lactide)/poly(oxyethylene) blends

POLYMER

卷:54

Article

Nguyen-Dung Tien¹  Ta-Phuong Hoa²  Mochizuki, Masatsugu³  Saijo, Kenji⁴  Hasegawa, Hirokazu⁴  Sasaki, Sono^1,3  Sakurai, Shinichi^1,3 

[1] Kyoto Inst Technol, Dept Biobased Mat Sci, Sakyo Ku, Kyoto 6068585, Japan

[2] Hanoi Univ Sci & Technol, Ctr Polymer, Hanoi, Vietnam

[3] Kyoto Inst Technol, Ctr Fiber & Text Sci, Kyoto 6068585, Japan

[4] Kyoto Univ, Dept Polymer Chem, Kyoto 6068501, Japan

关键词: Higher-order crystalline structure;    Poly(oxyethylene);    Poly(lactide);   

DOI  :  10.1016/j.polymer.2013.06.028

来源: Elsevier

【 摘 要 】

Higher-order crystalline structures in blends of poly(lactide)/poly(oxyethylene) (PLA/PEG) were investigated using small-angle X-ray scattering (SAXS). For this purpose, the fact that two polymers are both crystalline makes situation much complicated. To simplify, we used non-crystalline PLA: poly(D,L-lactide) (DLPLA), which is a racemic copolymer comprising D- and L-lactide moieties. Higher-order peaks arising from the ordered lamellar stacking of PEG (i.e. the lattice peaks) were observed in the various blend samples, as well as in the PEG 100% sample, all of which were cast from their solutions in dichloromethane. Surprisingly, we found that the structure is more or less regular in the blend of DLPLA/PEG at compositions of 5-20 wt% of DLPLA than that in the PEG 100% sample. We further examined changes in such regular structures with temperature and found very peculiar SAXS profiles just 1 degrees C below melting temperature, which can be ascribed to a lamellar particle scattering. To our best knowledge, such a well-defined particle scattering has neither been reported for polymer blends, nor for the crystalline lamellar structure. Moreover, crossover from the lattice scattering to the particle scattering was observed in the temperature range from room temperature to 64 degrees C for the PEG 100% sample and blend samples with 5-20 wt% of DLPLA. (c) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

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