Flash DSC crystallization study of blown film grade bimodal high density polyethylene (HDPE) resins. Part 2. Non‐isothermal kinetics

Abstract

Non‐isothermal ultra‐fast cooling crystallization tests were conducted on three blown film grade bimodal high density polyethylene (HDPE) resins using a fast differential scanning calorimeter, the Flash DSC. Non‐isothermal tests were performed at cooling rates between 50 and 4000°K/s, and the data were analyzed using the modified Avrami model by Jeziorny (Polymer, 1978, 19, 1142). Non‐isothermal data were used to propose a new method named crystallization–time–temperature–superposition, and the two activation energies were obtained for each of the resins. This is very useful for obtaining theoretical crystallization kinetics data at different cooling rates, allowing its use in ultra‐fast cooling polymer processes such as blown film. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1822–1827

Understanding Glass through Differential Scanning Calorimetry

“…Different cooling rates in a wide range, 50 to 4000 K/s, were used for studying the thermal activity of HDPE. The crystallization temperature decreases with higher cooling rate, as expected. In isothermal studies, in which the sample is fast cooled from the melt to the crystallization temperature, and the isothermal heat flow is measured, the same dependence between the crystallization temperature and the cooling rate of HDPE was also observed …”

“…Treviño-Quintanilla and co-workers reported results regarding the nonisothermal crystallization of high-density polyethylene (HDPE) resins . The melting enthalpy was determined by Flash DSC.…”

“…42 Trevinõ-Quintanilla and co-workers reported results regarding the nonisothermal crystallization of high-density polyethylene (HDPE) resins. 633 The melting enthalpy was determined by Flash DSC. Different cooling rates in a wide range, 50 to 4000 K/s, were used for studying the thermal activity of HDPE.…”

Thermoanalytical and dynamic mechanical analysis of commercial geomembranes used for fluid retention of leaching in sanitary landfills

“…4b), it can be seen that the melting point in DSC curves widens when compared to the first heating, which was attributed to the molecular relaxation. Figure 4d shows the cooling of the materials, where the exothermic reaction from 115°C can be seen, which was attributed to the recrystallization of the material, while the weak exothermic events seen after peak recrystallization between -3 and -53°C are attributed to molecular rearrangement [27].…”

From Molecular Entanglement Network to Crystal-Cross-Linked Network and Crystal Scaffold during Film Blowing of Polyethylene: An in Situ Synchrotron Radiation Small- and Wide-Angle X-ray Scattering Study

“…However, this modified ERM model still describes a one-step transition from the polymer melt with reduced entropy to crystal . Actually, even for the “short-term flow”, there is still enough time for generation of crystals during flow (shorter than 1 s for PE and iPP). − These flow-induced crystals can act as the physical cross-links, forming the crystal-cross-linked network. − Then, the deformation of the crystal-cross-linked network and the relative displacement between nuclei and their surrounding chains may happen during flow, which complicate the mechanism of FIC. With the presence of crystal-cross-linked network, polymer chains are expected to deform more easily, which further accelerates nucleation .…”