Effect of Microdomain Structure on the Mechanical Behavior of Binary Blends  

作　　者：Bin Su Yong-sheng Zhao 陈枫 傅强 

机构地区：[1]College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering,Sichuan University

出　　处：《Chinese Journal of Polymer Science》2015年第7期964-975,共12页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51173112 and 51121001);the Special Funds for Major State Basic Research Projects of China(No.2011CB606006)

摘　　要：The relationship between microphase structure and mechanical response of the binary blends consisting of polystyrene-block-polyisoprene-block-polystyrene copolymer and low molecular weight polystyrene has been investigated. Low molecular weight polystyrene was chosen to obtain uniformly solubilized nano-blends without macrophase separation. The specimens were solution-cast by adding different amounts of homo-polystyrene to acquire different microphase structures. Small angle X-ray scattering（SAXS）, transmission electron microscopy（TEM） and atom force microscopy（AFM） have been used to study the microdomain and grain structure. It is observed that the structural changes in d-spacing and grain size on account of different amounts of polystyrene alter the mechanical behavior in both monotonic tensile and cyclic tests. The elastic and the Mullins effects are strongly sensitive to the changes in d-spacing and grain sizes. Moreover, the sample with bi-continuous structure shows the largest tensile strength and Mullins effect. In addition, the Mooneye-Rivlin phenomenological model was used to evaluate and explore the relationship between the polymer topological networks and the rubber elasticity of these styrenic nano-blends.The relationship between microphase structure and mechanical response of the binary blends consisting of polystyrene-block-polyisoprene-block-polystyrene copolymer and low molecular weight polystyrene has been investigated. Low molecular weight polystyrene was chosen to obtain uniformly solubilized nano-blends without macrophase separation. The specimens were solution-cast by adding different amounts of homo-polystyrene to acquire different microphase structures. Small angle X-ray scattering（SAXS）, transmission electron microscopy（TEM） and atom force microscopy（AFM） have been used to study the microdomain and grain structure. It is observed that the structural changes in d-spacing and grain size on account of different amounts of polystyrene alter the mechanical behavior in both monotonic tensile and cyclic tests. The elastic and the Mullins effects are strongly sensitive to the changes in d-spacing and grain sizes. Moreover, the sample with bi-continuous structure shows the largest tensile strength and Mullins effect. In addition, the Mooneye-Rivlin phenomenological model was used to evaluate and explore the relationship between the polymer topological networks and the rubber elasticity of these styrenic nano-blends.

关 键 词：Microphase Grain size d-Spacing Bi-continuous structure Elastic response 

分 类 号：O631.21[理学—高分子化学]