This effort provides a multifaceted analysis of the structural changes and material dynamics of thermally driven softening and curing of three distinct phthalonitrile (PN) resins that cross‐link into thermally stable and oxidation‐resistant thermosets. Although this material system has yielded a large subset of fire‐retardant composites that require facile processing and low‐temperature curing, to date, insufficient information had been available on the fundamental processes that drive their softening and curing stages. Our approach conducted a complementary analysis the chemistry, monomer mobility, and rheology of three PN polymers in order to correlate the curing processes with corresponding structural and behavioral transformations of thermosets. We focused on PNs with a bisphenol S backbone, a bisphenol A (PEEK^TM‐like) backbone, and a resveratrol backbone. We relied on quasi‐elastic neutron scattering (QENS) in order to analyze the in situ dynamics and self‐diffusion properties of PN monomers, and to track changes in their mobilities during cross‐linking and staging. Our analysis facilitates proper control over the staging and final curing of these resins and enables more efficient processing of these thermosets.

中文翻译：

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双酚S，类PEEKTM和白藜芦醇邻苯二甲腈热固性树脂的化学结构和固化动力学

这项工作对交联成热稳定和抗氧化热固性材料的三种不同的邻苯二甲腈（PN）树脂的热驱动软化和固化的结构变化和材料动力学进行了多方面的分析。尽管此材料系统已产生大量需要简便加工和低温固化的阻燃复合材料，但迄今为止，有关推动其软化和固化阶段的基本工艺的信息尚不足。我们的方法对三种PN聚合物的化学，单体迁移率和流变性进行了补充分析，以使固化过程与热固性塑料的相应结构和行为转变相关。我们专注于具有双酚S主链，双酚A（PEEK ^TM样）骨架和白藜芦醇骨架。我们依靠准弹性中子散射（QENS）来分析PN单体的原位动力学和自扩散特性，并跟踪其在交联和阶段化过程中迁移率的变化。我们的分析有助于对这些树脂的阶段性和最终固化进行适当的控制，并使这些热固性塑料的加工效率更高。