Crystallization-rate of Saran
I. Influence of Crystallization Temperature
1959 Volume 16 Issue 172 Pages 495-498
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1959 Volume 16 Issue 172 Pages 495-498
In the extrusion of Saran, the crystallization-rate of molten polymer is controlled by extrusion conditions. The influence of temperature on the crystallization-rate, as measured by the density gradient tube method, is discussed. The crystallization-rate constant, k, decreases with the lowering of the temperature. The induction period of crystallization ττichanges with the temperature. The temperature at which the induction period is less than one second is estimated to be about 80-90°C This value agrees with the temperature reported by R. Boyer. In the relation between log ττiand 1/T, a break point was found at about 15°C and at the temperature below this point, ττi increases rapidly. This point agrees with the second-order transition point of Saran. However, in the relation between the specific volume of amorphous polymer and the temperature, the second-order transition point was not confirmed.
