Investigation of structural inhomogeneities in soft‐block modified methacrylate resins

Wideline 1 H NMR and selective high‐resolution 13 C cross‐polarization magic angle spinning (CP/MAS) NMR spectroscopy was used to investigate the polymer structure in methacrylate thermoset resins modified by the incorporation of a polyether soft‐block. Spin diffusion experiments indicate phase separation between a hard‐ and soft‐block phase. Similar soft‐block domain sizes were found regardless of the soft‐block content, reflecting the discriminatory nature of the delay used to create the magnetisation gradient. The main effect of increasing the polyether content is to ensure that more of the sample adopts a two‐phase hard/soft morphology. The selective 13 C CP/MAS NMR spectra show that partial mixing of the methacrylate resin and polyether must occur and adding a Goldman‐Shen preparation period establishes that the mixing occurs through the bulk and is not simply interfacial.