Monitoring the condition of thermally aged polymers by NMR relaxation measurements

Nuclear magnetic resonance (NMR) relaxation measurements are a microscopic probe of the dynamical behavior of a polymer chain. Various NMR relaxation measurements have been tested to determine their effectiveness for monitoring the condition of thermally aged polymers. The most convenient and promising approach utilizes 1 H NMR T 2 relaxation times of samples swollen in deuterated solvents. These relaxation times show an excellent correlation to traditional mechanical degradation parameters such as ultimate tensile elongation. In addition, these measurements are sensitive to the early stages of aging and can be performed on very small samples.