Sulfur-containing imidazole fiber having ionically bonded halides
The present invention concerns fiber made from a polymer comprising imidazole groups, fiber further having: i) a halide anion, the halide anion being present in an amount of 0.05 to 20.1 weight percent, based on weight of fiber; and ii) sulfur, wherein the sulfur is present in the fiber in an amount of 0.05 to 3 weight percent.
1. A fiber made from a polymer comprising imidazole groups, the fiber further having:
i) halide anions, the halide anions being present in an amount of 0.05 to 20.1 weight percent, based on weight of fiber, and ionically bound to protonated imidazole groups in the polymer, and
ii) sulfur, wherein the sulfur is present in the fiber in an amount of 0.05 to 3 weight percent, based on the weight of the fiber,
wherein the fiber has a yarn tenacity of 32 cN/dtex (35.6 gpd) or higher.
2. The fiber of claim 1 , where the halide anions are present in an amount of 0.05 to 10 weight percent, based on weight of the fiber and sulfur is present in an amount of 0.05 to 1 weight percent, based on the weight of the fiber.
3. The fiber of claim 1 wherein the halide anions are present in an amount of 0.1 to 5 weight percent.
4. The fiber of claim 3 wherein the halide anions are present in an amount of 0.1 to 1 weight percent.
5. The fiber of claim 1 , wherein said polymer comprises residues of 5(6)-amino-2-(p-aminophenyl)benzimidazole, aromatic diamine, and aromatic diacid-chloride.
6. The fiber of claim 5 , wherein said aromatic diacid-chloride is terephthaloyl dichloride.
7. The fiber of claim 5 , wherein said aromatic diamine is para-phenylenediamine.
8. The fiber of claim 5 having a molar ratio of 5(6)-amino-2-(p-aminophenyl)benzimidazole to aromatic diamine in the range of from 30/70 to 85/15.
9. The fiber of claim 8 , wherein the molar ratio of 5(6)-amino-2-(p-aminophenyl)benzimidazole to aromatic diamine is 45/55 to 85/15.
10. The fiber of claim 1 , wherein said halide anions comprise one or more of F—, Cl—, Br—, and I—.
11. The fiber of claim 10 , wherein said halide anions comprise one or more of Cl— and Br—.
12. The fiber of claim 1 wherein the fiber has 0.1 to 1.75 percent sulfur by weight.
13. The fiber of claim 12 wherein the fiber has 0.1 to 1.0 percent sulfur by weight.
14. A yarn comprising fiber of claim 1 .
15. Fabric comprising yarn of claim 14 .
16. The yarn of claim 14 wherein the yarn tenacity is 34 cN/dtex (37.8 gpd) or higher.
17. The yarn of claim 16 wherein the yarn tenacity is 36 cN/dtex (40 gpd) or higher.