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首页> 外文期刊>Polymer: The International Journal for the Science and Technology of Polymers >Comparison of poly(ethylene oxide) crystal orientations and crystallization behaviors in nano-confined cylinders constructed by a poly (ethylene oxide)-b-polystyrene diblock copolymer and a blend of poly(ethylene oxide)-b-polystyrene and polystyrene
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Comparison of poly(ethylene oxide) crystal orientations and crystallization behaviors in nano-confined cylinders constructed by a poly (ethylene oxide)-b-polystyrene diblock copolymer and a blend of poly(ethylene oxide)-b-polystyrene and polystyrene

机译：聚（环氧乙烷）-b-聚苯乙烯二嵌段共聚物和聚（环氧乙烷）-b-聚苯乙烯与聚苯乙烯的共混物构成的纳米约束圆柱体中聚环氧乙烷的晶体取向和结晶行为的比较

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A poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymer with a number average molecular. weight of PEO blocks, M-n(PEO) = 8.8 kg/mol, and a number average molecular weight of PS blocks, M-n(PS) = 24.5 kg/mol, (volume fraction of the PEO blocks, f(PEO), was 0.26) exhibited a hexagonal cylinder (HC) phase structure. Small angle X-ray scattering results showed that the PEO cylinder diameter was 13.3 run, and the hexagonal lattice was a = 25.1 nm. The cylinder diameter of this HC phase structure was virtually the same as that in the blend system constructed by a PEO-b-PS diblock copolymer (M-n(PEO) = 8.7 kg/mol and M-n(PS) = 9.2 kg/mol) and a PS homo-polymer (M-n(PS) = 4.6 kg/mol) in which the f(PEO) was 0.32. The cylinder diameter in this blend sample was 13.7 nm and the hexagonal lattice was a = 23.1 nm. Comparing crystal orientation and crystallization behaviors of this PEO-b-PS copolymer with the blend, it was found that the crystal orientation change with respect to crystallization temperature was almost identical. This is attributed to the fact that in both cases the PEO block tethering densities and confinement sizes are very similar. This indicates that when the M-n(PS) of PS homo-polymer is lower than the PS blocks, the PS homo-polymer is located inside of the PS matrix rather than at the interface between the PEO and PS in the HC phase structure. On the other hand, a substantial difference of crystallization behaviors was observed between these two samples. The PEO-b-PS copolymer exhibited much more retarded crystallization kinetics than that of the blend. Based on the small angle X-ray scattering results, it was found that in the blend sample, the HC phase structure was not as regularly ordered as that in the PEO-b-PS copolymer, and thus, the HC phase structure contained more defects in the blend. This led to a suggestion that the primary nucleation process in the confined crystallization is a defect-controlled process. The mean crystallite sizes were estimated by the Scherer equation, and the PEO crystal sizes are on the scale of the confined size. (c) 2006 Elsevier Ltd. All rights reserved.
机译：具有数均分子的聚（环氧乙烷）-b-聚苯乙烯（PEO-b-PS）二嵌段共聚物。 PEO嵌段的重量，Mn（PEO）= 8.8 kg / mol，PS嵌段的数均分子量，Mn（PS）= 24.5 kg / mol，（PEO嵌段的体积分数，f（PEO）为0.26 ）表现出六角圆柱（HC）相结构。小角X射线散射结果表明，PEO圆柱体直径为13.3nm，六边形晶格为a ＝ 25.1nm。 HC相结构的圆柱直径实际上与PEO-b-PS二嵌段共聚物（Mn（PEO）= 8.7 kg / mol和Mn（PS）= 9.2 kg / mol）构成的共混体系中的圆柱直径相同，一种PS均聚物（Mn（PS）＝ 4.6kg / mol），其中f（PEO）为0.32。该共混物样品中的圆柱直径为13.7nm，六边形晶格为a ＝ 23.1nm。将这种PEO-b-PS共聚物与共混物的晶体取向和结晶行为进行比较，发现相对于结晶温度的晶体取向变化几乎相同。这归因于在两种情况下，PEO块的束缚密度和限制尺寸非常相似的事实。这表明，当PS均聚物的M-n（PS）低于PS嵌段时，PS均聚物位于PS基质内部，而不是HC相结构中PEO和PS之间的界面。另一方面，在这两个样品之间观察到明显的结晶行为差异。与共混物相比，PEO-b-PS共聚物表现出更多的延迟结晶动力学。基于小角度X射线散射结果，发现在共混样品中，HC相结构不如PEO-b-PS共聚物中的规则排列，因此，HC相结构包含更多的缺陷。在混合中。这表明在有限的结晶中的主要成核过程是缺陷控制的过程。平均晶体尺寸通过Scherer方程估算，并且PEO晶体尺寸在受限尺寸的尺度上。 （c）2006 Elsevier Ltd.保留所有权利。

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