Cooling rate effect

To study cooling rate effects which might affect the supramolecular self-assembly of trisamides in i-PP, we investigated the influence of the processing conditions on the electret performance. Isotactic polypropylene containing 0.09 wt% of compound 1 was chosen for these experiments. After compression molding, the films... 

Chang, R. Y, Chen, C. H., and Su, K. S., Modifying the Tait equation with cooling-rate effects to predict the pressure-volume-temperature behaviors of amorphous polymers modeling and experiments, Polym. Eng. Sci., 36, 1789-1795 (1996). 

Toro-Vazquez JF, Morales-Rueda J, Torres-Martinez A, Charo-Alonso MA, Mallia VA, Weiss RG. Cooling rate effects on the microstructure, solid content, and rheological properties of organogels of amides derived from stearic and (R)-12-hydroxystearic acid in vegetable oil. Langmuir. 29(25)... 

Fig. 38. Cooling rate effect on observed PET endothom areas and peak temperatures. The sample was remelted at 10° C/min after each different cooling...

Fig. 6.17 The generalized spin auto-correlation function (t) for temperatures T = 0.40,0.30,0.25,0.23, and 0.22 are plotted versus t/tsc (in logarithmic scale) where tsc = 130,400,1160,2260 and 3700 for the respective temperatures. All the curves collapse onto a single curve at late times. This result stems from a simulation of the 2d version of model A with N = 10, P = 200, and = 0.8 after eliminating all cooling rate effects.

We remark that the coupling-model predictions for contraction, i.e. 8>0, while reasonable at small AT, fit less well at large AT. This was attributed to finite cooling-rate effects, not accounted for in equation (92). Furthermore, the coupling-model predictions have not been compared with other experiments, e.g. memory effect, uniform heating through the transition, etc., and ultimate confirmation of the model awaits such quantitative comparison. The results presented above as an explanation of the x-effective paradox are encouraging. 

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