Abstract
The temperature evolution of biphase segregation at the N-I as well as SA-N and SB-SA transitions of a main chain polyester I was studied by annealing the sample inside the relevant biphasic gaps. The thermodynamic width of the mesophasic transitions were 2 °C for the N-I transition and 6 and 4 °C for the SA-N and SB-SA transitions, respectively. The maximum efficiency of the biphase demixing, in terms of peak resolution, was found for the transitions at which the demixing was performed. It was suggested that the system lowers its free energy by selective redistribution of species of different molar masses between two different phases. The analysis of polyester I fractions with different molar masses and molar mass distributions showed that the location of the peaks moves to higher temperatures as the average molar mass increases. In addition, the width of the overall biphase segregation process was wider for the sample with the widest molar mass distribution, thus clearly indicating that the molar mass parameters are key factors in determining the overall biphase segregation phenomenology.
Lingua originale | Inglese |
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pagine (da-a) | 7190-7196 |
Numero di pagine | 7 |
Rivista | Macromolecules |
Volume | 34 |
Numero di pubblicazione | 20 |
DOI | |
Stato di pubblicazione | Pubblicato - 25 set 2001 |