Liquid crystalline poly (2,6-benzothiazole) compositions, process, and products
AssigneeSRI International
InventorsJames F. Wolfe, Paul D. Sybert, Joanne R. Sybert, Blake Wilson
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Abstract
Novel compositions comprising a high concentration of poly(2,6-benzothiazole) and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.
Claims19
A process for preparing an extended chain polymer composition of workable viscosity which is useful as a dope in the production of fibers and films, said composition comprising liquid crystalline poly(2,6-benzothiazole), said process comprises the following steps:
- (a) mixing a selected monomer with or without oxidation protecting atoms or groups with a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,
- (b) heating and optionally placing the resulting mixture under reduced pressure to remove any volatilized protecting atoms or groups present and provide a solution of the monomer in the preliminary solvent,
- (c) then increasing the phosphorus pentoxide content of the mixture resulting from step (b) by adding phosphorus pentoxide in two or more portions to provide a monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,
- (d) causing polymerization of the monomer at a temperature sufficient to effect reaction at a rate to form a homo-oligomeric product having a preselected intrinsic viscosity or a homopolymeric product.
A process for preparing an extended chain polymer composition of workable viscosity which is useful as a dope in the production of fibers and films, said composition comprising a liquid crystalline poly(2,6-benzothiazole), and said process comprises:
- (a) incorporating a selected monomer in a preliminary solvent of phosphoric acid having a relatively low phosphorus pentoxide content,
- (b) increasing the phosphorus pentoxide content of the resultant preliminary solvent by adding phosphorus pentoxide in two or more portions to provide a monomer reaction medium of greater phosphorus pentoxide content suitable for polymerization,
- (c) causing polymerization of the monomer at a temperature sufficient to effect reaction at a rate to form a polymer having a preselected intrinsic viscosity.
Dependencies are inferred from the claim text.