Effect of Polymer Composition and Morphology on Mechanochemical Activation in Nanostructured Triblock Copolymers

被引：21

作者：

Huo, Zijian ^{[1
]}

Arora, Swati ^{[1
]}

Kong, Victoria A. ^{[1
]}

Myrga, Brandon J. ^{[1
]}

Statt, Antonia ^{[2
]}

Laaser, Jennifer E. ^{[1
]}

机构：

[1] Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15260 USA

[2] Univ Illinois, Grainger Coll Engn, Mat Sci & Engn, Champaign, IL 61801 USA

来源：

MACROMOLECULES | 2023年 / 56卷 / 05期

基金：

美国国家科学基金会;

关键词：

FORCE; SPIROPYRAN; DISORDER; BEHAVIOR; ORDER;

D O I：

10.1021/acs.macromol.2c02475

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The effect of composition and morphology on mechanochemical activation in nanostructured block copolymers was investigated in a series of poly(methyl methacrylate)-block-poly(n-butyl acrylate)-block-polycontaining a force-responsive spiropyran unit in the center of the rubbery PnBA midblock. Triblock copolymers with identical PnBA midblocks and varying lengths of PMMA end-blocks were synthesized from a spiropyrancontaining macroinitiatior via atom transfer radical polymerization, yielding polymers with volume fractions of PMMA ranging from 0.21 to 0.50. Characterization by transmission electron microscopy revealed that the polymers self-assembled into spherical and cylindrical nanostructures. Simultaneous tensile tests and optical measurements revealed that mechanochemical activation is strongly correlated to the chemical composition and morphologies of the triblock copolymers. As the glassy (PMMA) block content is increased, the overall activation increases, and the onset of activation occurs at lower strain but higher stress, which agrees with predictions from our previous computational work. These results suggest that the self-assembly of nanostructured morphologies can play an important role in controlling mechanochemical activation in polymeric materials and provide insights into how polymer composition and morphology impact molecular-scale force distributions.

引用

页码：1845 / 1854

页数：10

共 51 条

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