Methods of dynamic mechanical analysis using nuclear magnetic resonance

Abstract

Method of dynamic mechanical analysis of a sample including providing a magnet with a constant gradient where at least a portion of the sample is in the constant gradient, inducing a vibration in the sample in the direction of the constant gradient, the vibration comprising a vibration waveform and a vibration period, generating an NMR pulse sequence comprising at least two pulses with a delay between the pulses, acquiring echos from the pulse sequence at multiple points along the vibration period, measuring the phase of the NMR signal at each of the acquired echos, using the phase of the NMR signal to measure the velocity of the vibration at the multiple points where the echos are acquired, using the velocity measurements to acquire a velocity waveform, and using the velocity waveform and processing the velocity waveform to extract the loss angle and the magnitude of the dynamic modulus of the sample.