Use after World War

Some organochlorine, organophosphorus, and carbamate insecticides used after World War II (since 1945) were found to have various problems of adverse effects on mammals and environmental behavior and influences. The use of many industrial chemicals has been prohibited because those contained as impurities in minute quantities produced critical toxic substances by transformation and repeated chemical reactions in their environment. 

While each of these milestones brought forth a renewed interest in chemical weed control and led to more research in the field, the use of chemicals for selective weed control in crops was very limited and not very successful until the discovery and development of 2,4-D, MCPA, and other phenoxyacetic acid herbicides in the 1940s. These compounds were the first truly selective herbicides that could reliably kill broadleaf weeds in cereal crops, including com, and they quickly developed widespread popularity and use after World War II. With this major milestone, new application technology emerged, including the low-volume sprayer, and new herbicide formulations were developed. 

Although the purification of TNT by sodium sulphite was widely used after World War I a number of factories continued with the crystallization method using among other solvents toluene, which directly after crystallization was used for nitration. 

Steam Supply and Condensate Removal All cylinder dryers are heated by the steam condensing inside the sheet because of its efficiency (heat-transfer coefficient for film condensation of steam ranges from 5,700 to 17,000 W/m K (1,000-3,(XX) Btu/h ft °F). In the early days of papermaking, steam pressures as low as 14-21 kPa (2-3 psi) were used after World War n, the new machines for Kraft papers were made... 

In this field, Schutzenberger demonstrated the possibility of obtaining cellulose acetate, a derivative soluble in various organic solvents. His discovery seems to have been made without any application in mind but from then on, his main focus was on nitro-cellulose derivatives, in particular for artificial textile production. In that field, Schutzenberger was a scientific initiator, but not an innovator. Nevertheless, his works on cellulose acetate were useful after World War I, when new acetate fibres were developed that replaced nitrocellulose. 

Ma.nufa.cture. AU. manufacturers of butynediol use formaldehyde ethynylation processes. The earliest entrant was BASF, which, as successor to I. G. Farben, continued operations at Ludwigshafen, FRG, after World War II. Later BASF also set up a U.S. plant at Geismar, La. The first company to manufacture in the United States was GAF in 1956 at Calvert City, Ky., and later at Texas City, Tex., and Seadrift, Tex. The most recent U.S. manufacturer is Du Pont, which went on stream at La Porte, Tex., about 1969. Joint ventures of GAF and Hbls in Mad, Germany, and of Du Pont and Idemitsu in Chiba, Japan, are the newest producers. 

Ma.nufa.cture. Butyrolactone is manufactured by dehydrogenation of butanediol. The butyrolactone plant and process in Germany, as described after World War II (179), approximates the processes presendy used. The dehydrogenation was carried out with preheated butanediol vapor in a hydrogen carrier over a supported copper catalyst at 230—250°C. The yield of butyrolactone after purification by distillation was about 90%. 

Although a few simple hydrides were known before the twentieth century, the field of hydride chemistry did not become active until around the time of World War II. Commerce in hydrides began in 1937 when Metal Hydrides Inc. used calcium hydride [7789-78-8J, CaH2, to produce transition-metal powders. After World War II, lithium aluminum hydride [16853-85-3] LiAlH, and sodium borohydride [16940-66-2] NaBH, gained rapid acceptance in organic synthesis. Commercial appHcations of hydrides have continued to grow, such that hydrides have become important industrial chemicals manufactured and used on a large scale. 

Lime stabilization originated in Texas after World War II, and now it is used throughout the world. Lime is most commonly applied at a 4 wt % application or ca 11 kg/m (20 Ib/yd ) for 15 cm of compacted depth. It can be applied dry as hydrated time or granular quicklime or as a wet slurry. Distribution of the latter form is dusfless. Copious amounts (as much as 5—10%) of water are always needed in excess of the optimum moisture content of the soil. Then, a requisite for success is intimate mixing with a rotary mixer, followed by compaction to a minimum of 95% Proctor density. 

Manufacture and Processing. Terephthalic acid and dimethyl terephthalate did not become large-volume industrial chemicals until after World War II. Imperial Chemical Industries in the United Kingdom in 1949 and Du Pont in the United States in 1953 commercialized fibers made from poly(ethylene terephthalate). Dimethyl terephthalate and ethylene glycol were the comonomers used by both companies (see Fibers, polyester). 

Sodium ethoxide was the first metal alkoxide described in 1837 (1). The alkoxides of many transition metals were developed after World War II (2—5). Today some alkoxides, including those of sodium, potassium, magnesium, aluminum, zirconium, and titanium, are commercially important. The name metal alkoxides is preferred, although metal alcoholates is also used. 

After World War II, analytical methods for amino acids were improved and new methods were iatroduced. The first was microbial assay usiag lactic acid bacteria which require all of the regular amino acids for growth. Manometric determiaation (by use of a Warburg manometer) of CO2 Hberated by the... 

The first appHcation of the gas turbine principle to a ground system was in 1906 when waste heat from furnace gases was used to operate a turboblower which compressed air for a blast furnace. Developments in metallurgy and compressor design after World War I led, in 1937, to the first... 

After World War I, other chlohne-based bleaches were developed. In 1921 the use of chlorine dioxide for bleaching fibers was reported followed by the development of the commercial process for large-scale production of sodium chlorite. In 1928 the first dry calcium hypochlorite containing 70% available chlorine was produced in the United States. This material largely replaced bleaching powder as a commercial bleaching agent. 

During World War I, cellulose acetate replaced the highly flammable cellulose nitrate coating on airplane wings and the fuselage fabrics. After World War I, it found extensive use in photographic and x-ray films, spun fibers, and mol ding plastics. 

Guayule, potentially a source of natural mbber, is an unusual crop in that it has been an article of commerce in the past. Guayule grows wild in northern Mexico and the southwestern United States. When the leaves are milled in water, a latex is released that coagulates into natural mbber worms. These can easily be collected and relatively easily refined to give a product that is almost identical to the natural mbber from southeast Asia. During World War II there were several thousand acres of guayule planted in California and a small plant estabUshed to extract the mbber for military use. After the war. 

The Dow Chemical Company in the mid-1920s developed two processes which consumed large quantities of chlorobenzene. In one process, chlorobenzene was hydrolyzed with ammonium hydroxide in the presence of a copper catalyst to produce aniline [62-53-3J. This process was used for more than 30 years. The other process hydrolyzed chlorobenzene with sodium hydroxide under high temperature and pressure conditions (4,5) to product phenol [108-95-2]. The LG. Earbenwerke in Germany independentiy developed an equivalent process and plants were built in several European countries after World War II. The ICI plant in England operated until its dosing in 1965. 

Instant coffee is the dried water-extract of ground, roasted coffee. Although used in Army rations as eady as the U.S. Civil War, the popularity of instant coffee as a grocery product grew only after World War II, coincident with improvements in manufacturing methods and consumer trends toward convenience. Extensive patent Hterature dates back to 1865. Instant coffee products represented 15% of the coffee consumed in the United States in 1991 (31). 

Simplified nitrile mbber polymerization recipes are shown in Table 2 for "cold" and "hot" polymerization. Typically, cold polymerization is carried out at 5°C and hot at 30°C. The original technology for emulsion polymerization was similar to the 30°C recipe, and the redox initiator system that allowed polymerization at lower temperature was developed shortiy after World War II. The latter uses a reducing agent to activate the hydroperoxide initiator and soluble iron to reactivate the system by a reduction—oxidation mechanism as the iron cycles between its ferrous and ferric states. 

Shock-compression science originated during and after World War II when experimental facilities for creating planar shock waves were developed, along with prompt instrumentation techniques enabling shock velocity and particle velocity measurements to be made. The main thrust of shock-compression science is to understand the physics and to measure the material properties which govern the outcome of shock-compression events. Experiments involving planar shock waves are the most useful in shock-compression science. 

---