The effect of polymer structure on fragility was determined by relating the apparent fragility to the relaxation response, heat capacity, and thermal expansion. For the 14 polymers studied, the fragility estimates based on the relaxation behavior (log aT) correlated well with the thermodynamic estimates of ΔCp/Mo, and Δα. In general, polymers with less sterically hindered repeat unit structures exhibited strong behavior. Polymers with sterically hindered backbones containing oxygen or ringed structures in the backbone were consistently fragile using log aT, ΔCp/Mo, and Δ α as measures of fragility. On the other hand, using Cp1/Cpg as a fragility criterion resulted in very different fragility classifications.
|Number of pages||6|
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - 1997|
|Event||Proceedings of the 1996 MRS Fall Meeting - Boston, MA, USA|
Duration: Dec 2 1996 → Dec 6 1996