CHAIN FOLDING IN EBEE SEMICRYSTALLINE DIBLOCK COPOLYMERS
CHAIN FOLDING IN EBEE SEMICRYSTALLINE DIBLOCK COPOLYMERS
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DOI：
10.1021/ma00045a033
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发表时间：
1992-09-14
期刊：
影响因子：
5.5
通讯作者：
COHEN, RE
中科院分区：
文献类型：
--
作者：
DOUZINAS, KC;COHEN, RE
采用X射线极图分析和小角X射线散射方法确定了乙烯-丁烯-b-乙基乙烯（EBEE）半结晶二嵌段共聚物相对于片层微观结构的晶格晶胞取向。的X-射线数据表明，结晶的EB链的取向是垂直于片层法线，不像链折叠已观察到的半结晶均聚物和提出的半结晶二嵌段共聚物，其中结晶的链对齐大致平行于片层法线。EBEE观察到的不寻常的链折叠是由于拓扑约束的影响，EB块结晶内的非晶层状微区中存在的嵌段共聚物的非均相熔体相。
X-ray pole-figure analysis and small-angle X-ray scattering were used to determine the lattice unit cell orientation with respect to the lamellar microstructure for semicrystalline diblock copolymers of ethylene-co-butylene-b-ethylethylene (EBEE). The X-ray data indicate that the orientation of the crystallized EB chains is perpendicular to the lamellar normals, unlike the chain folding which has been observed in semicrystalline homopolymers and proposed for semicrystalline diblock copolymers where the crystallized chains align roughly parallel to the lamellar normals. The unusual chain folding observed for EBEE is attributed to the influence of topological constraints on the EB blocks which crystallize within the amorphous lamellar microdomains present in the heterogeneous melt phase of the block copolymers.