Multiscale Network Structure Analysis by Time Domain 1H DQ NMR and DMA of Resorcinol Diglycidyl Ether‐Jeffamine Matrices

Abstract

AbstractEpoxy‐amine networks have found their way in everyday and technical applications for the past several years. Special attention on biosourced monomers has increased for sustainable development applications. This work investigates the influence of the chemical structure on the thermomechanical behavior of biosourced epoxy‐based matrices through a multiscale approach. Resorcinol Diglycidyl Ether (RE) was hardened with Jeffamines (molecular weights MW≈230, 500, 800, and 2000 g mol−1). Bisphenol A Diglycidyl Ether (DGEBA) was also studied for comparison. By combining Dynamic Mechanical Analysis (DMA) and Time Domain Nuclear Magnetic Resonance (NMR), it was proven that the difference in the chemical structure of Jeffamines yielded matrices with distinct network morphologies, influencing the behavior of the matrices. A linear relationship between the crosslink densities probed by DMA and Time NMR was observed, demonstrating a direct influence of the network structure at the molecular level with the obtained macroscopic properties. It was demonstrated that physical entanglements in these matrices act as mechanical reinforcements. This work shows a novel and robust multiscale experimental approach allowing to understand key structure‐property relationships for epoxy‐amine thermosets.