Polybenzimidazole fibers

A report130 of DSC measurements on polybenzimidazole fibers describes important differences for the glass transition temperature depending on die mechanical treatment of the fiber. An as-spun fiber exhibits a Tg at 387°C instead of 401°C for a drawn fiber free to shrink or 435°C for a drawn fiber widi fixed length. 

Reverse osmosis membranes. The exceptionally hi moisture regain observed with polybenzimidazole fibers prompted a team at Ctelanese Research Co to investigate the utility of polybenzimidazole films as semipermeable membranes for reverse osmosis processes, sudi as sea water desalination A continuous process was devised in which films were... 

Reverse osmosis memhraaes. The exceptionally high moisture regain observed with polybenzimidazole fibers prompted a team at Celanese Research Co to investigate the utility of polybenzimidazole films as semipermeable membranes for reverse osmosis processes, such as sea water desalination66,94). A continuous process was devised in which films were cast from solution into a water precipitation bath. The films were tested for reverse osmosis performance with a saline solution (0.5% Nad) as feed stream at a pressure of 4.14 MN m-2 and a flow rate of 19.8 m min-1. Salt rejection was ca. 95% throughout. A cellulose acetate film of the type commonly used as a reverse osmosis standard was tested under the same conditions for comparison. Table 8 shows the results. 

The polybenzimidazole fiber PBl was originally developed as a flame-resistant textile fiber for the US aerospace program. Because of their high oxygen index, they... 

A polybenzimidazole fiber is treated with an acid such as H2SO4 to form a polybenzimida-zonium salt, which is then oxidized at 400-550°C and can be carbonized in an inert atmosphere at 650-875°C to form a carbonaceous fibrous material with at least 60% w/w carbon. The product can then be oxidized at 450-600°C to give an activated carbonaceous fibrous material [305]. 

Conciatori A, Buckley A, Stuetz D (1985) Polybenzimidazole fibers. High technology fibers part A, Handbook of fiber science and technology. Marcel Dekker, New York... 

Polybenzimidazole (PBI) Fibers. Poly(2,2 -(y -phenylene)-5,5 -bisbenzimidazole) [25734-65-0] is a textile fiber marketed by Hoechst-Celanese (11) which does not form Hquid crystalline solutions due to its bent meta backbone monomeric component. PBI has exceUent resistance to high temperature and chemicals. 

Polybenzimidazoles Developmental laminating resin, fiber, film stable 24 hours at 300°C (572°F) in air. 

Polyazo dyes, 9 363—361 Polybenzamide, 15 109-110 Poly(p-benzamide) (PBA), 10 212 19 714 crystal lattice parameters of, 19 728t laboratory synthesis of, 19 719 Polybenzimidazole (PBI), asbestos substitute, 3 3141 Polybenzimidazole (PBI) fibers,... 

A number of plastics are condensation polymers and include polyesters and nylons that are not as highly oriented as the same materials but in fiber form. Other plastics have been developed that have outstanding heat stability, strength, and other properties that allow their wide use. These plastics include polycarbonates, polyimides, polybenzimidazoles, polysulfides, polyethers, polysulfones, and polyketones. 

The resulting polybenzimidazole is amorphous and shows a very high glass transition temperature of 425 °C. It is highly flame resistant. Therefore, FBI fibers that are spun from solution, are used for the production of fireproof protection clothes and also for fabrics of airplane seats. 

Syntactic materials based on polybenzimidazole and glass or phenolic microspheres (y = 40-500 kg/m3) have been described in the literature109 nl). They have been used as ablation materials that consist of two layers, one of which is a monolithic carbon plastic. Carbon fiber was added to the polyimide binder to improve the mechanical properties of the material. 

Several other fibrous materials have been produced, but they are regarded as fibers with special performance characteristics, used either in limited textile or in specialized industrial applications. Some of these worth noting are Spandex (1959), Aramid (1961), polybenzimidazole (PBI) (1983), and Sulfar (1983). 

Poly-2-2 -(w-phenylene)-5,5 -bibenzimidazole, commonly called polybenzimidazole (PBI), was developed under the aegis of the U.S. Air Force Materials Laboratory in cooperation with the then-existing Celanese Corporation. The fiber went into commercial production in the United States in 1983. It is a condensation polymer obtained from the reaction of tetra-aminobiphenyl and diphenylisophthalate in a nitrogen atmosphere at temperatures that may reach 400°C in the final stages.29 The structure of a repeating unit is shown below. 

Pol ybenzImidazole asym tube Polybenzimidazole asym hoi low fiber Polylmide, methoxyl 10 pm... 

In 1983 Celanese began the production of polybenzimidazole (PBI) by using diphenyl isophthalate and 3,3 -diaminobenzidine, DAB. PBI is a high-temperature and flame-resistant fiber, used in the production of safety gloves and various items of protective clothing as well as for the production of PBI-based membranes for reverse osmosis and ultrafiltration applications. 

Polybenzimidazole asym tube Polybenz i mi dazole asym hollow fiber Polylmide, methoxyl iO pm... 

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