On the Kinetics of Shear Induced Crystallization in Polypropylene
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S. Liedauer
Abstract
With short term shearing at low degrees of supercooling a method has been developed by which nucleation during shearing can effectively be separated from the subsequent crystal growth, which, in these experiments, mainly occurs after the cessation of the flow. In this way the kinetics of nucleation by shear could be unravelled for isotactic polypropylene. The required measurement consists of the monitoring of the optical retardation which increases with the monitoring time and levels off by saturation. From these measurements conclusions could be drawn with respect to the modes of formation of the nuclei and of their type. Model predictions could be confirmed with the aid of electron micrographs.
© 1993, Carl Hanser Verlag, Munich
Articles in the same Issue
- Contents
- Contents
- Mixing
- Processing-Structure-Properties Relationships in Blends with Thermotropic Liquid Crystalline Polymers
- Screw Extrusion
- Extrusion of Recycled Polymer Feedstocks
- A Unified View of Modeling Flow in Counter-rotating Twin Screw Extruders
- Experimental Study on Dewatering and Devolatilizing Operations Using Intermeshed Twin Screw Extruders
- Molding
- Simulation of Injection Molding and Comparison with Experimental Values
- On the Kinetics of Shear Induced Crystallization in Polypropylene
- Structures and Properties of Injection Moldings of Glass Fiber-filled Polypropylenes
- Detailed Investigations of Structural Layering Phenomena in Injection Molded Thermotropic Liquid Crystalline Polymers
- Material Flow During Compression Moldings of Long Fiber Reinforced Thermoplastic Composites
- Rapid Communication of Recent Advances
- Dimensional Control of Multicomponent Extrusion
Articles in the same Issue
- Contents
- Contents
- Mixing
- Processing-Structure-Properties Relationships in Blends with Thermotropic Liquid Crystalline Polymers
- Screw Extrusion
- Extrusion of Recycled Polymer Feedstocks
- A Unified View of Modeling Flow in Counter-rotating Twin Screw Extruders
- Experimental Study on Dewatering and Devolatilizing Operations Using Intermeshed Twin Screw Extruders
- Molding
- Simulation of Injection Molding and Comparison with Experimental Values
- On the Kinetics of Shear Induced Crystallization in Polypropylene
- Structures and Properties of Injection Moldings of Glass Fiber-filled Polypropylenes
- Detailed Investigations of Structural Layering Phenomena in Injection Molded Thermotropic Liquid Crystalline Polymers
- Material Flow During Compression Moldings of Long Fiber Reinforced Thermoplastic Composites
- Rapid Communication of Recent Advances
- Dimensional Control of Multicomponent Extrusion