Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Macro Lett. 2021 Jul 20;10(7):805-810. doi: 10.1021/acsmacrolett.1c00255. Epub 2021 Jun 14.
"Drop-in" additives that introduce chemically cleavable bonds into thermosets without compromising thermomechanical properties could enable triggered material deconstruction and enhanced sustainability. While the installation of cleavable bonds into the strands of the commercial thermoset polydicyclopentadiene (pDCPD) using comonomers facilitates chemical deconstruction, these additives can lower the material's glass transition temperature (). By contrast, the installation of cleavable crosslinkers into pDCPD can maintain or potentially increase but does not facilitate chemical deconstruction. Here, we introduce "strand-cleaving crosslinker" (SCC) additives that provide cleavable pDCPD network junctions. Notably, pDCPD samples featuring 10% v/v of SCCs can be deconstructed under mild conditions to yield soluble products and display a 48 °C higher than analogous decontructable pDCPD made using cleavable comonomers and an equivalent to virgin pDCPD. The SCC concept could offer a general strategy for the design of chemically deconstructable thermoset materials without compromise on thermomechanical performance.
“即插即用”添加剂可将可化学裂解的键引入热固性塑料中，而不会损害热机械性能，从而实现触发式材料解构和提高可持续性。虽然使用共聚单体在商业热固性聚二环戊二烯（pDCPD）的链中安装可裂解键有助于化学解构，但这些添加剂会降低材料的玻璃化转变温度（Tg）。相比之下，将可裂解的交联剂安装到 pDCPD 中可以保持或可能提高 Tg，但不会促进化学解构。在这里，我们引入了“链断裂交联剂”（SCC）添加剂，它提供了可裂解的 pDCPD 网络连接点。值得注意的是，含有 10%v/v SCC 的 pDCPD 样品可以在温和条件下进行解构，得到可溶产物，并显示出比使用可裂解共聚单体和相同量的原始 pDCPD 制备的可解构 pDCPD 高 48°C 的 Tg。SCC 概念为设计具有化学可解构性的热固性材料提供了一种通用策略，而不会损害热机械性能。
