TY - JOUR
T1 - Extremely fragile glass-formers? Calorimetric and rheological determinations
AU - Torres Arellano, Astrid K.
AU - McKenna, Gregory B.
N1 - Publisher Copyright:
© 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1261-1272.
PY - 2015/9/15
Y1 - 2015/9/15
N2 - We use calorimetry and rheology to investigate reports of extremely fragile polymers and the speculation that d,l-lactic acid should be extremely fragile. The dynamic fragilities of lactic acid, polysulfone, bisphenol-A polycarbonate, and poly(vinyl chloride) were studied. The polymers were used as received and after a wash-precipitation treatment. The current dynamic fragility findings are not in agreement with those reported by C. Evans, H. Deng, W. Jager, J. Torkelson, Macromolecules 2013, 46 (15), 6091-6103 of extremely high fragilities for the mentioned polymers. We also found no sample preparation history effect on the dynamic fragility values. The calorimetric and rheological results for the d,l-lactic acid show dynamic fragility values that are consistent with each other and are not extremely fragile. Calorimetric measurements that use a broad range of cooling rates gave smaller dynamic fragility values than those obtained from a limited range at higher cooling rates. The importance of the results is discussed.
AB - We use calorimetry and rheology to investigate reports of extremely fragile polymers and the speculation that d,l-lactic acid should be extremely fragile. The dynamic fragilities of lactic acid, polysulfone, bisphenol-A polycarbonate, and poly(vinyl chloride) were studied. The polymers were used as received and after a wash-precipitation treatment. The current dynamic fragility findings are not in agreement with those reported by C. Evans, H. Deng, W. Jager, J. Torkelson, Macromolecules 2013, 46 (15), 6091-6103 of extremely high fragilities for the mentioned polymers. We also found no sample preparation history effect on the dynamic fragility values. The calorimetric and rheological results for the d,l-lactic acid show dynamic fragility values that are consistent with each other and are not extremely fragile. Calorimetric measurements that use a broad range of cooling rates gave smaller dynamic fragility values than those obtained from a limited range at higher cooling rates. The importance of the results is discussed.
KW - calorimetry
KW - dynamic fragility
KW - lactic acid, glass formation, polymers, rheology
KW - polycarbonate
KW - polysulfone
KW - viscosity
UR - http://www.scopus.com/inward/record.url?scp=84938747282&partnerID=8YFLogxK
U2 - 10.1002/polb.23768
DO - 10.1002/polb.23768
M3 - Article
AN - SCOPUS:84938747282
SN - 0887-6266
VL - 53
SP - 1261
EP - 1272
JO - Journal of Polymer Science, Part B: Polymer Physics
JF - Journal of Polymer Science, Part B: Polymer Physics
IS - 18
ER -