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Process for the preparation of fibers of stereoregular polystyrene

Assignee: Dow Chemical Co
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Filing: 1989-08-19
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Granted: —
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Expires: 2009-08-19
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Abstract

Abstract The invention is a process for the preparation of fibers of syndiotactic polystyrene, or a mixture of isotactic polystyrene and syndiotactic polystyrene which comprises: A. heating syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene, to a temperature between its crystal melting point and the temperature at which the polystyrene undergoes degradation, wherein the polystyrene has sufficient viscosity to be extruded; B. extruding the polystyrene through an orifice to form a fiber at elevated temperatures; C. quenching the fiber by passing the fiber through one or more zones under conditions such that the fiber solidifies; and D. cooling the fiber to ambient temperature. The fibers prepared according to this invention are useful for making composites.

Inventors

  • 👤 David R. Pedersen

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-29 03:47
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/20; D01F6/22

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 102 words
A process for the preparation of fibers of syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene which comprises: A. heating syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene, to a temperature between its crystal melting point and the temperature at which the polystyrene undergoes degradation, wherein the polystyrene has sufficient viscosity to be extruded; B. extruding the polystyrene through an orifice to form a fiber at elevated temperatures; C. quenching the fiber by passing the fiber through one or more zones under conditions such that the fiber solidifies; and D. cooling the fiber to ambient temperature.
Claim 2
Dependent Claim 102 words
A process for the preparation of fibers of syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene which comprises: A. heating syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene, to a temperature between its crystal melting point and the temperature at which the polystyrene undergoes degradation, wherein the polystyrene has sufficient viscosity to be extruded; B. extruding the polystyrene through an orifice to form a fiber at elevated temperatures; C. quenching the fiber by passing the fiber through one or more zones under conditions such that the fiber solidifies; and D. cooling the fiber to ambient temperature.
Claim 3
Dependent Claim 48 words
A process of Claim 1, which after step D of Claim 1, further comprises: E. heating the fiber to a temperature above the glass transition temperature of the polystyrene; and F. redrawing the fiber to elongate the fiber and induce monoaxial orientation of the polystyrene in the fiber.
Claim 4
Dependent Claim 18 words
The process of Claim 2, wherein the fiber is quenched by passing the fiber through an air zone.
Claim 5
Dependent Claim 24 words
The process of Claim 3, wherein the polystyrene is heated prior to extrusion to, and extruded at, a temperature of between 260°C and 320°C.
Claim 6
Dependent Claim 18 words
The process of Claim 4, wherein the temperature of the air quench zone is between 0°C and 100°C.
Claim 7
Dependent Claim 24 words
The process of Claim 5, wherein the fiber is drawn down in the air quench zone at a ratio of between 10:1 and 100:1.
Claim 8
Dependent Claim 20 words
The process of Claim 6, wherein the fiber is heated for redraw to a temperature of between 150°C and 280°C.
Claim 9
Dependent Claim 19 words
The process of Claim 7, wherein the fiber is redrawn to an elongation ratio of between 1.5:1 and 10:1.
Claim 10
Dependent Claim 19 words
The process of Claim 8, wherein the fiber has a tensile strength of 68,948 kPa (10,000 psi) or greater.
Claim 11
Dependent Claim 50 words
A high strength fiber of syndiotactic polystyrene, or a mixture of syndiotactic polystyrene and isotactic polystyrene prepared by the process of Claim 1, wherein the fiber is monoaxially oriented, has a tensile strength of 68,948 kPa (10,000 psi) or greater, and a modulus of 6,894,800 kPa (1,000,000 psi) or greater.

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