Self-Assembly of Poly(styrene- block -acrylated epoxidized soybean oil) Star-Brush-Like Block Copolymers
Self-Assembly of Poly(styrene- block -acrylated epoxidized soybean oil) Star-Brush-Like Block Copolymers
复制标题
聚(苯乙烯嵌段丙烯酸酯化环氧化大豆油)星刷状嵌段共聚物的自组装
DOI：
10.1021/acs.macromol.0c00441
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发表时间：
2020
期刊：
影响因子：
5.5
通讯作者：
Cochran, Eric W.
中科院分区：
文献类型：
--
作者：
Lin, Fang-Yi;Hohmann, Austin D.;Hernández, Nacú;Shen, Liyang;Dietrich, Hannah;Cochran, Eric W.
在这里，我们报告的动态和热力学方面的自组装在一系列支链大豆油衍生苯乙烯嵌段共聚物通过可逆加成-破碎链转移（RAFT）聚合生产。这些生物基材料显示出在常规石油基嵌段共聚物中没有看到的不寻常的畴扩展。聚苯乙烯-b-丙烯酸化环氧大豆油嵌段共聚物（PS-PAESO）由于PAESO重复单元的体积和多功能性，其链结构从星形到星刷状不等。通过（超）小角度x射线散射（SAXS）、透射电子显微镜和动态剪切流变学来评估自组装行为。PS-PAESO中的微相分离受到动力学限制，因为链动力学缓慢，由于交联反应的干扰而不能热加速。残留的PAESO乙烯基选择性加氢延缓但不消除交联反应，表明酯交换也在起作用。SAXS实验表明，PS-PAESO结构域的尺寸与统计片段的数量几乎成线性关系，可以观察到大asd= 155 nm的结构。我们认为，结构域的扩张与PAESO结构域中庞大的脂肪侧链有关，这些侧链延伸了主链主干，产生了刷子状构象。对这些新型生物基嵌段共聚物的结构-性能关系的理解，为新型聚合物结构的设计提供了见解，有利于新的应用。
Here we report dynamic and thermodynamic aspects of the self-assembly in a series of branched-chain soybean-oil-derived styrenic block copolymers produced via reversible addition–fragmentation chain transfer (RAFT) polymerization. These biobased materials display unusual domain expansion which has not been seen in conventional petroleum-based block copolymers. The chain architecture of poly(styrene-b-acrylated epoxidized soybean oil) (PS–PAESO) block copolymers varies from star-like to star-brush-like owing to the bulk and multifunctionality of the PAESO repeat unit. The self-assembly behavior is evaluated through a combination of (ultra) small-angle X-ray scattering (SAXS), transmission electron microscopy, and dynamic shear rheology. Microphase separation in PS–PAESO is kinetically limited due to sluggish chain dynamics that cannot be thermally accelerated due to interference from cross-linking reactions. Selective hydrogenation of the residual PAESO vinyl groups retards but does not eliminate cross-linking reactions, indicating that transesterification is also at play. SAXS experiments show that the PS–PAESO domain size scales nearly linearly with the number of statistical segments, with structures as large asd= 155 nm observed. We believe that domain dilation is related to bulky aliphatic side chains in PAESO domains that extend the primary chain backbone to produce a brush-like conformation. The understanding of the structure–property relationships of these new biobased block copolymers gives insights on the design of novel polymer architectures benefiting new applications.