Most elastomers are formed using solvent-based processes which result in an environmental burden. Consequently, elastomers formed using water-based nanoparticle dispersions are highly desirable. Here, we investigate elastomer-like films based on water-dispersible carboxylic acid-containing core–shell (CS) nanoparticles. The nanoparticles contain a poly(n-butylacrylate) (PBA) core and a poly(BA-co-acrylonitrile-co-methacrylic acid) shell. We react the –COOH groups of the shell with a di-epoxide (1,4-butanediol diglycidyl ether, BDDE) which replaces dissipative hydrogen bonds in the nanoparticle elastomer films with covalent bonds. The reaction with BDDE enables the transformation of a stretchable dissipative film (shear modulus of 9.0 MPa with 20% strain energy recovery) into a predominantly elastic film (shear modulus of 0.20 MPa with almost 100% energy recovery). Our optimum system, CS-0.5, has a shear modulus of 0.40 MPa, an impressive strain-at-break of greater than 300% and an energy recovery of 80%. The strain-at-break is increased to more than 450% using a monofunctional epoxide. We further explore the inter- and intra-nanoparticle nature of the di-epoxide reaction and how the mechanical properties can be tuned by varying the method of film formation. The facile approach introduced here enables the tuning of the mechanical properties of elastomeric core–shell nanoparticle films from dissipative to predominantly elastic on demand.

中文翻译：

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使用二环氧交联将高模量水基弹性核壳纳米颗粒薄膜从粘弹性转化为主要弹性薄膜


大多数弹性体是使用溶剂型工艺形成的，这会导致环境负担。因此，使用水基纳米颗粒分散体形成的弹性体是非常理想的。在这里，我们研究了基于水分散性含羧酸的核壳 （CS） 纳米颗粒的弹性体样薄膜。纳米颗粒包含一个聚（正丁基丙烯酸酯）（PBA） 核心和一个聚（BA-co-丙烯腈-co-甲基丙烯酸）壳。我们将壳的 –COOH 基团与二环氧化物（1,4-丁二醇二缩水甘油醚，BDDE）反应，二环氧化物用共价键取代纳米颗粒弹性体膜中的耗散氢键。与 BDDE 的反应使可拉伸耗散膜（剪切模量为 9.0 MPa，应变能回收率为 20%）转变为主要弹性膜（剪切模量为 0.20 MPa，能量回收率几乎为 100%）。我们的最佳系统 CS-0.5 的剪切模量为 0.40 MPa，令人印象深刻的大于 300% 的断裂应变和 80% 的能量回收率。使用单功能环氧化物将断裂应变增加到 450% 以上。我们进一步探讨了二环氧化物反应的纳米间和纳米内颗粒性质，以及如何通过改变成膜方法来调整机械性能。这里介绍的简单方法可以按需将弹性核壳纳米颗粒薄膜的机械性能从耗散调整为主要弹性。