Microstructure Formation in Extruded and Drawn Polyblends of PC with a Thermotropic LCP
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J. He
Abstract
Melt blending, extrusion and drawing of polycarbonate (PC) blends containing a thermotropic liquid crystalline polymer (LCP) are reported for a copolyester PCDT synthesised in this laboratory. A single screw extruder is used at four temperatures. The rheology of the PCDT/PC blend, PCDT and PC was measured by means of a capillary rheometer at these temperatures. The morphology of extruded and subsequently drawn strands was studied with the help of a scanning electron microscope and analysed. In PCDT/PC extruded strands, the morphology of the PCDT dispersed phase, changes from spherical through ellipsoidal to elongated with decreasing processing temperature. In contrast to this, in drawn strands with a draw ratio of 10, the morphology of the PCDT changes from ellipsoidal through elongated to fibrillar with increasing processing temperature. It is believed that the relative viscosity of the two phases is the decisive factor determining the microstructure formation of polymer blends containing thermotropic liquid crystalline polymers. Fibril formation is related to the deformation and coalescence of PCDT melt droplets by the drawing at higher temperatures.
© 1993, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Contents
- Contents
- Internal Mixers
- Estimation of Quality of Mixing
- Screw Extrusion and Continuous Mixing
- An In-line Rheometer for Molten Plastics
- Melting of Plastics in Kneading Blocks
- Development of Phase Morphology of a Polyethylene-Polyamide 6-Blend in a Modular Co-rotating Twin Screw Extruder
- Microstructure Formation in Extruded and Drawn Polyblends of PC with a Thermotropic LCP
- Die Extrusion
- A Slip Model for Linear Polymers Based on Adhesive Failure
- Film
- Effect of Biaxial Stretching on Mechanical Properties and Surface Roughness of PMMA Films
- Molding
- Dynamics and Control of Surface and Mold Temperatures in Injection Molding
- A Study on Flexural Properties of Sandwich Injection Moldings
- Detailed Investigations of Structural Layering Phenomena in Injection Molded Thermotropic LCP
- Computer Controlled Rotational Molding of Liquid Silicone Polymer
Artikel in diesem Heft
- Contents
- Contents
- Internal Mixers
- Estimation of Quality of Mixing
- Screw Extrusion and Continuous Mixing
- An In-line Rheometer for Molten Plastics
- Melting of Plastics in Kneading Blocks
- Development of Phase Morphology of a Polyethylene-Polyamide 6-Blend in a Modular Co-rotating Twin Screw Extruder
- Microstructure Formation in Extruded and Drawn Polyblends of PC with a Thermotropic LCP
- Die Extrusion
- A Slip Model for Linear Polymers Based on Adhesive Failure
- Film
- Effect of Biaxial Stretching on Mechanical Properties and Surface Roughness of PMMA Films
- Molding
- Dynamics and Control of Surface and Mold Temperatures in Injection Molding
- A Study on Flexural Properties of Sandwich Injection Moldings
- Detailed Investigations of Structural Layering Phenomena in Injection Molded Thermotropic LCP
- Computer Controlled Rotational Molding of Liquid Silicone Polymer
