Cylindrical to Lamellar Microdomain Transition upon Heating for a Linear Tetrablock Copolymer with Upper Critical Ordering Transition
Cylindrical to Lamellar Microdomain Transition upon Heating for a Linear Tetrablock Copolymer with Upper Critical Ordering Transition
复制标题
具有上临界有序转变的线性四嵌段共聚物在加热时从圆柱形到层状微域的转变
DOI：
10.1021/acs.macromol.9b01690
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发表时间：
2019-11-26
期刊：
影响因子：
5.5
通讯作者：
Li, Weihua
中科院分区：
文献类型：
--
作者：
Ahn, Seonghyeon;Seo, Yeseong;Li, Weihua
We investigated the order-to-order transition (OOT) of the polystyrene-block-polyisoprene-block-polystyrene-block-polyisoprene (S1I1S2I2) linear tetrablock copolymer at the symmetric volume fraction of total PS and PI blocks but asymmetry of the PI block (tau(PI) = f(PI1)/(f(PI1) + f(PI2)) = 0.19), in which f(PI1) and f(PI2) are the volume fractions of PI in the second and fourth blocks, respectively. Very interestingly, this block copolymer showed cylindrical to lamellar microdomain transition upon heating. Such a behavior is exactly the opposite of commonly observed OOT for the linear AB diblock and A(1)BA(2) triblock copolymers with upper critical ordering transition, where lamellar microdomains have been transformed to cylindrical microdomains upon heating. This interesting transition sequence is due to the chain architecture of the linear tetrablock copolymer with two PS and two PI blocks. Experimentally observed microdomains during the transition are consistent with predicted equilibrium microdomains by the self-consistent field theory.
