Essential work of fracture to evaluate toughness in interfacially modified HDPE/TPS blends

International audienc

Influence of melt-down ratio and composition on drop coalescence in PA6/HDPE blends

The deformation of polyamide-6 drops in high density polyethylene at different compositions and melt-drawn ratio was studied. The mixtures were prepared using a twin-screw extruder with a rectangular slit at 250 °C. The rectangular sheets were cooled in water and then taken up on a roll. The extrusion velocity was maintained constant at 100 cm/min. The take up velocity was varied in order to obtain different states of deformation of the minor phase. The morphology results show that at low take up velocity the final state deformation is independent on the dispersed phase composition. However, at high take up velocity the drop deformation increases with the composition. This result may be explained in terms of the coalescence phenomena. In the determination of average particle volume of the dispersed phase as a function of the drawn ratio, it was observed that the coalescence effects becomes important at concentration higher than 5% volume of PA6

Essential work of fracture to evaluate toughness in interfacially modified HDPE/TPS blends

International audienc

Influence of melt-down ratio and composition on drop coalescence in PA6/HDPE blends

The deformation of polyamide-6 drops in high density polyethylene at different compositions and melt-drawn ratio was studied. The mixtures were prepared using a twin-screw extruder with a rectangular slit at 250 °C. The rectangular sheets were cooled in water and then taken up on a roll. The extrusion velocity was maintained constant at 100 cm/min. The take up velocity was varied in order to obtain different states of deformation of the minor phase. The morphology results show that at low take up velocity the final state deformation is independent on the dispersed phase composition. However, at high take up velocity the drop deformation increases with the composition. This result may be explained in terms of the coalescence phenomena. In the determination of average particle volume of the dispersed phase as a function of the drawn ratio, it was observed that the coalescence effects becomes important at concentration higher than 5% volume of PA6

Barrier properties of polyamide-6/high density polyethylene blends

The barrier properties of Polyamide-6 (PA6)/High Density Polyethylene (HDPE) blends with and without compatibilizer prepared by ribbon extrusion were studied. The results show that the toluene diffusivity was improved by the addition of an interfacial agent and by inducing orientation of the polymer chains. The presence of PA-6 in the blend results in a decrease of the toluene diffusivity. This reduction is even larger for the case of the interfacial modified system. However, the most important reduction of the toluene diffusivity is observed for pure HDPE when stretched. A six-fold decrease is observed when the draw ratio is increased two fold. In the case of the permeability of different solvents through blends a gravimetric permeation cell was used. The results show that the permeability decreases with increasing size of the penetrant molecules (CH2Cl2, CHCl3 and CCl4) and this decrease is more important for a compatibilized blend

Deformation of drops in extensional viscoelastic flow

The deformation of nylon drops in polyethylene, with and without an interfacial agent, in an extensional flow has been studied. The presence of an interfacial agent reduces the size of the dispersed phase, and the deformation of the drop is reduced. An analysis is given, which accurately predicts the deformation for all values of the capillary number considered. The predicted and observed shapes are, however, only in agreement at low values of capillary number. Possible causes for this discrepancy are discussed. © 1996 John Wiley & Sons, Inc

Depolarization for quantum channels with higher symmetries

The deformation of nylon drops in polyethylene, with and without an interfacial agent, in an extensional flow has been studied. The presence of an interfacial agent reduces the size of the dispersed phase, and the deformation of the drop is reduced. An analysis is given, which accurately predicts the deformation for all values of the capillary number considered. The predicted and observed shapes are, however, only in agreement at low values of capillary number. Possible causes for this discrepancy are discussed. " 1996 John Wiley & Sons, Inc.",,,,,,,,,"http://hdl.handle.net/20.500.12104/40506","http://www.scopus.com/inward/record.url?eid=2-s2.0-0030571459&partnerID=40&md5=226d2e4eedefd0cc5709832311400dd6",,,,,,"10",,"Journal of Applied Polymer Science",,"162

Determination of a limiting dispersed phase concentration for coalescence in PA6/HDPE blends under extensional flow

Blends of PA6/HDPE at different compositions and melt-draw ratio were prepared using a twin-screw extruder with a rectangular slit at 250�C. The morphology results show that at low take up velocity, the final state of deformation is independent of the dispersed phase composition. However, at high take up velocity the drop deformation increases with the composition. To determine a lower limiting concentration, at which coalescence occurs, the average particle volume of the dispersed phase was evaluated. In the concentration range of 1-4 vol% of PA6, the average volume of the particles remains constant (no coalescence) during the stretching process. However, at higher concentrations (>5 vol% of PA6) coalescence takes place and the volume increases with stretching. These results clearly indicate the limiting dispersed phase concentration for coalescence in this system under extensional flow. The approach used here represents a possible technique to separate out the relative contribution of single particle deformation and particle-particle coalescence in dispersed phase fiber formation in an extensional flow field. � 2001 Elsevier Science Ltd