| Popis: |
Dynamic calorimetry and thermomechanics have been used to study the effects of changes in the urethane diol block on the phase structure and the thermal properties of thermoelastoplasts (TEP) based on polybutylene adipate (PBA), 4,4-diphenyl-methane diisocyanate (DPMIC) and glycols of low molecular weight. The properties of TEP greatly depended on the ratio of blocks present, the glycol type, and the excess of NCO groups over the OH groups. The heat contents, heat of phase transitions, crystallinity of the PBA block, ranges of the melting and glassification temperatures of the TEP series with differing compositions, all indicated regular changes in the phase structure and a corresponding distribution of molecular interactions. The glass formation was examined in TEP in accordance with the free volume theory. |
