Structural change with blending of crystalline/amorphous block copolymers having different types of microphase separations

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• 作者：Masaki  ; Kakiage¹ ; Miho  ; Sekiya ; Takeshi  ; Yamanobe ; Hiroki  ; Uehara  ; ;   ; ^{hirokiuehara@gunma-u.ac.jp}
• 关键词：Block copolymer ; Blend ; Morphology
• 刊名：Polymer
• 出版年：2011
• 出版时间：13 December 2011
• 年：2011
• 卷：52
• 期：26
• 页码：6146-6153
• 全文大小：1529 K

文摘

Two kinds of polystyrene/polyethylene diblock copolymers exhibiting bicontinuous and spherical microphase separations were blended at different ratios. Initial films were prepared by hot xylene dissolution, followed by casting and drying. The obtained films were melted and isothermally crystallized at various temperatures. Differential scanning calorimetry melting peak temperatures for the isothermally crystallized films suggested that characteristic crystal growth occurred at critical bicontinuous/spherical blend ratios of 90/10 and 85/15. The crystalline structure consisted of interior pure crystals and exterior defective crystals. Transmission electron microscopy observations of these blended films indicated the progressive isolation of the amorphous phase with increases in the spherical component. Specifically, the mixed morphologies of both the bicontinuous and spherical structures were obtained for the above critical blend ratios. Analysis implied that this unique morphology was formed as a result of the combination of the crystal nucleus effect and the competitive growth effect.