Solid-state nmr of network polymers

The poly left bracket (ethylene glycol) dimethacrylates right bracket range from brittle glassy, through rubbery, to semicrystalline network polymers. They and their copolymers provide an ideal medium for establishing structure-property relationships. Preliminary results on two glassy and one rubbery dimethacrylate networks have already been reported. The authors now report on a more extensive study of T//1// rho (H), T//1// rho (C), T//S//L and dynamic mechanical and fracture properties of these and other dimethacrylates. The PE/MAS experiment enables the problem of variable limiting extent of cure to be overcome. This and water content have a very significant effect on both NMR and mechanical dynamic parameters. These studies have been augmented by high power **1H spectrometry. This old technique, particularly when performed using modern equipment, is a valuable adjunct to PE/MAS **1**3C experiments.