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>Hydroxypropylcellulose, a thermotropic liquid crystal: Characteristics and structure development in continuous extrusion and melt spinning
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Hydroxypropylcellulose, a thermotropic liquid crystal: Characteristics and structure development in continuous extrusion and melt spinning
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机译：Hydroxypropylcellulose, a thermotropic liquid crystal: Characteristics and structure development in continuous extrusion and melt spinning
AbstractHot‐stage polarized light microscopy suggests that bulk hydroxypropylcellulose (Hercules Klucel E) is a cholesteric liquid crystal. Rheological measurements indicate this system exhibits shear viscosities similar to those of polyolefin melts except that it has a yield value comparable to suspensions. Birefringent characteristics were observed in shear flow between glass slides. No relaxation of birefringence is observed following flow. Extruded filaments (without applied take‐up tensions) show high levels of birefringence and significant orientations from WAXS measurements. These have skin‐core structure with highly oriented outer layers which are caused by the flow patterns in the reservior and die preceding the extrudate. In the case of melt‐spun filaments, where tensile elongation occurs, a highly oriented structure of uniform cross section i
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