Abstract
Pulse NMR methods have been employed to investigate the phase state and the process of phase separation in segmented PUs based on 1,4-butanediol and 4,4′-diphenylmethane diisocyanate with crystallizable (polybutylene glycol adipate) and non-crystallizable as part of PU (polybutylene ethylene glycol adipate) polyesters. For both samples the same T g of flexible blocks (-20°C) and temperature of the disappearance of the microphase of the rigid blocks (110°C) are observed. The segregation process was found to have two stages with acceleration as the temperature rises in a certain interval. The crystallization processes of the flexible blocks were found to influence the rate of segregation of the rigid blocks.
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