Latent curing agents are essential in the formulation of one-component epoxy resins, yet they are seldom derived from fully biobased chemicals. In the present work, a fully biobased latent curing agent for epoxy resins (BIMPA) was produced by synthesizing an ionic complex of lignin-derived triaryl-imidazole (BIM) and phytic acid (PA). Benefiting from the synergistic effect of BIM and PA, the one-component epoxy resin, composed of BIMPA and commercially available E51, exhibits a storage stability of over 90 days. Upon heating, the ionic complex undergoes decomposition, liberating the active imidazole to cure the precursor. The resulting epoxy resins exhibited a flexural modulus of 3.09 GPa, a flexural strength of 107.47 MPa, a notched izod impact strength of 2.47 kJ/m³, and a shear strength of 41.02 MPa. The outcome can provide an effective supplement for the development of biobased epoxy resins.

中文翻译：

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基于木质素三芳基咪唑与植酸协同作用的高性能单组份环氧胶粘剂


潜伏性固化剂在单组分环氧树脂的配方中至关重要，但它们很少源自完全生物基化学品。在目前的工作中，通过合成木质素衍生的三芳基咪唑（BIM）和植酸（PA）的离子复合物，生产了一种全生物基环氧树脂潜伏性固化剂（BIMPA）。受益于BIM和PA的协同效应，由BIMPA和市售E51组成的单组份环氧树脂具有超过90天的储存稳定性。加热后，离子络合物发生分解，释放出活性咪唑以固化前体。所得环氧树脂的弯曲模量为3.09 GPa，弯曲强度为107.47 MPa，缺口伊佐德冲击强度为2.47 kJ/m ³ ，剪切强度为41.02 MPa。该成果可为生物基环氧树脂的发展提供有效的补充。