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46-480: Vinyl polymers are the most common type of plastic. Important examples can be distinguished by the R group in the monomer H 2 C=CHR: Vinyl polymers are produced using catalysts. Ziegler–Natta catalysts are used commercially for production of polyethylene and polypropylene. Many are produced using radical initiators which are produced from organic peroxides . Still others (polystyrene) are produced using anionic initiators such as butyl lithium . An exception from

92-534: A large variety of ligands containing oxygen (O 2 ), nitrogen (N 2 ), phosphorus (P), and sulfur (S). The complexes are activated using MAO, as is done for metallocene catalysts. Most Ziegler–Natta catalysts and all the alkylaluminium cocatalysts are unstable in air, and the alkylaluminium compounds are pyrophoric . The catalysts, therefore, are always prepared and handled under an inert atmosphere. The structure of active centers in Ziegler–Natta catalysts

138-429: A mixture of those two patterns. Additionally the substituted carbon center in such polymers is stereogenic (a "chiral center"), with the result that the relative absolute configurations of these centers within a polymer can influence the properties of the polymer. This feature is called tacticity . The polymerization conditions and the catalysts affect tacticity. Another major variation for vinyl polymers arises from

184-550: A newly-built complex known as the Union Carbide Corporate Center . 270 Park Avenue later became the headquarters of JPMorgan Chase . The building was demolished and replaced with a new 1,200-foot-tall (370 m) tower serving as the consolidated headquarters for JPMorgan Chase. At 700 feet (210 m) tall, the Union Carbide Building was the tallest building in the world ever voluntarily demolished at

230-442: A possible 'runaway reaction'. Around midnight on 3 December 1984, gas was accidentally released from the plant, exposing more than 500,000 people to MIC and other chemicals. The Government of Madhya Pradesh confirmed a total of 16,000 deaths related to the gas release. It left an estimated 40,000 individuals permanently disabled, maimed, or suffering from serious illness, making it the world's worst industrial disaster . Following

276-414: A solid with a high surface area. Both TiCl 4 and TiCl 3 give active catalysts. The support in the majority of the catalysts is MgCl 2 . A third component of most catalysts is a carrier, a material that determines the size and the shape of catalyst particles. The preferred carrier is microporous spheres of amorphous silica with a diameter of 30–40 mm. During the catalyst synthesis, both

322-452: A special feature of the polymer structure called stereoregularity . The concept of stereoregularity in polymer chains is illustrated in the picture on the left with polypropylene. Stereoregular poly(1-alkene) can be isotactic or syndiotactic depending on the relative orientation of the alkyl groups in polymer chains consisting of units −[CH 2 −CHR]−, like the CH 3 groups in the figure. In

368-595: A valve failure after a buildup of pressure in a storage tank containing 500 pounds of the chemical. A company spokesman insisted that the aldicarb oxime leak "never was a threat to the community." Union Carbide's operations in Australia commenced in 1957, when it purchased the plant of the Australian-owned company Timbrol Ltd. The Timbrol factory was on the shore of Homebush Bay in the Sydney suburb of Rhodes . Homebush Bay

414-455: Is amorphous. The stereoregularity of the polymer is determined by the catalyst used to prepare it. The first and dominant class of titanium-based catalysts (and some vanadium -based catalysts) for alkene polymerization can be roughly subdivided into two subclasses: The overlap between these two subclasses is relatively small because the requirements to the respective catalysts differ widely. Commercial catalysts are supported by being bound to

460-462: Is an organic modifier, usually an ester of an aromatic diacid or a diether . The modifiers react both with inorganic ingredients of the solid catalysts as well as with organoaluminum cocatalysts. These catalysts polymerize propylene and other 1-alkenes to highly crystalline isotactic polymers. A second class of Ziegler–Natta catalysts are soluble in the reaction medium. Traditionally such homogeneous catalysts were derived from metallocenes , but

506-462: Is normally produced using a base chemical, methyl isocyanate (MIC). Initially this plant imported MIC, but in 1979 the company decided to manufacture the ingredients on their own. They built a MIC unit within the Bhopal plant. This plant was located next to a very densely populated neighbourhood, and heavily trafficked railway station. Locating it near this densely populated area was a direct violation of

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552-575: Is on the Parramatta River which flows into Sydney Harbour . Tibrol produced phenol , the insecticides chlorobenzene / chlorophenol / DDT , and the herbicides 2,4-D and 2,4,5-T . Union Carbide continued the production of the 2,4-D and 2,4,5-T until 1976 and chlorobenzene/chlorophenol/DDT until 1983. Union Carbide also commenced the production of bisphenol A in 1960 and phenol formaldehyde resins in 1964. Union Carbide reclaimed land on neighboring properties by depositing spent lime and ash into

598-430: Is well established only for metallocene catalysts. An idealized and simplified metallocene complex Cp 2 ZrCl 2 represents a typical precatalyst. It is unreactive toward alkenes. The dihalide reacts with MAO and is transformed into a metallocenium ion Cp 2 + Zr CH 3 , which is ion-paired to some derivative(s) of MAO. A polymer molecule grows by numerous insertion reactions of C=C bonds of 1-alkene molecules into

644-573: The Cold War , the company was active in the field of rocket propulsion research and development for aerospace and guided missile applications, particularly in the field of chemicals and plastics, solid rocket motors , and storable liquid fuels . R&D and engineering were conducted at the Technical Center in South Charleston, West Virginia . The Aerospace Materials Department was part of

690-621: The vinyl double bond): The 1963 Nobel Prize in Chemistry was awarded to German Karl Ziegler , for his discovery of first titanium-based catalysts, and Italian Giulio Natta , for using them to prepare stereoregular polymers from propylene . Ziegler–Natta catalysts have been used in the commercial manufacture of various polyolefins since 1956. As of 2010, the total volume of plastics, elastomers, and rubbers produced from alkenes with these and related (especially Phillips) catalysts worldwide exceeds 100 million tonnes. Together, these polymers represent

736-604: The 1975 Bhopal Development Plan. This development plan posed that hazardous industries such as the MIC plant be located in a different part of the city that was further away, and downwind, from more densely populated areas. According to one of the authors of the Bhopal Development Plan, "Union Carbide India Limited's" initial application for a permit was rejected, yet the company was able to gain approval from centralized governing authorities. In 1982, Carbide's auditors had warned of

782-497: The Bhopal disaster, a faulty valve at the UC plant in Institute, West Virginia caused a large cloud of gas that injured six employees and caused almost 200 nearby residents to seek medical treatment for respiratory and skin irritation. Union Carbide blamed the leak of aldicarb oxime (made from MIC but does not contain any MIC itself), the main ingredient in the popular farm pesticide Temik , on

828-524: The C=C bond into the Ti−C bond at the active center. On occasion, the polymer chain is disengaged from the active centers in the chain termination reaction. Several pathways exist for termination: Another type of chain termination reaction called a β-hydride elimination reaction also occurs periodically: Polymerization reactions of alkenes with solid titanium-based catalysts occur at special titanium centers located on

874-449: The Zr–C bond in the ion: Many thousands of alkene insertion reactions occur at each active center resulting in the formation of long polymer chains attached to the center. The Cossee–Arlman mechanism describes the growth of stereospecific polymers. This mechanism states that the polymer grows through alkene coordination at a vacant site at the titanium atom, which is followed by insertion of

920-550: The accident was an act of sabotage by a plant worker. The plant site has not yet been cleaned up. Hazardous chemicals can still be found in the now abandoned site. Warren Anderson , CEO at the time of the disaster, refused to answer to homicide charges and remained a fugitive from India's courts. The U.S. denied several extradition requests. Anderson died on 29 September 2014 in Florida. Seven UCC employees were convicted of criminal negligence in 2010 and fined $ 2,000 each. The year after

966-676: The activity of the titanium-based catalysts. These catalysts were so active that the removal of unwanted amorphous polymer and residual titanium from the product (so-called deashing) was no longer necessary, enabling the commercialization of linear low-density polyethylene (LLDPE) resins and allowed the development of fully amorphous copolymers. The fluidized-bed process remains one of the two most widely used processes for producing polypropylene . Natta first used polymerization catalysts based on titanium chlorides to polymerize propylene and other 1-alkenes. He discovered that these polymers are crystalline materials and ascribed their crystallinity to

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1012-630: The adjacent marshes in Homebush Bay . This practice, which had been approved by the Maritime Services Board, ceased in 1970. Union Carbide ceased operations in Australia in 1985. In 1987, the New South Wales Pollution Control Commission ordered Union Carbide to remediate the site. This work, which cost Union Carbide $ 30 million, was conducted between 1988 and 1993. The work involved excavation and encapsulation of

1058-461: The company set up a chemicals division which manufactured ethylene glycol for use as automotive antifreeze . The company continued to acquire related chemical producers, including the Bakelite Corporation in 1939. The company changed its name to "Union Carbide Corporation" in 1957 and was often referred to as Carbide. It operated Oak Ridge National Laboratory from 1947 to 1984. During

1104-566: The company's Carbon Products Division. Ucar batteries was Carbide's industrial and consumer zinc chloride battery business. The business, including Eveready and Energizer alkaline batteries , was sold to Ralston Purina in 1986, following a hostile takeover attempt. After the Bhopal disaster , Union Carbide was the subject of repeated takeover attempts. In order to pay off its debt, Carbide sold many of its most familiar brands such as Glad Trashbags and Eveready Batteries. Dow Chemical announced

1150-543: The contaminated soil. In 2004, the New South Wales Minister for Planning granted consent for additional remediation of the former Union Carbide site to proceed, including parts of Homebush Bay. Approximately 900,000 tons of soil were excavated from the site, 190,000 tons of soil from the adjacent Allied Feeds site, and approximately 50,000 tons of sediment from the bay. Remediation of the Allied Feeds Site

1196-545: The copolymerization of differing vinyl monomers. The simplest example is ethylene-propylene copolymer. The % comonomer is yet another variation. Ziegler%E2%80%93Natta catalyst A Ziegler–Natta catalyst , named after Karl Ziegler and Giulio Natta , is a catalyst used in the synthesis of polymers of 1-alkenes ( alpha-olefins ). Two broad classes of Ziegler–Natta catalysts are employed, distinguished by their solubility: Ziegler–Natta catalysts are used to polymerize terminal alkenes (ethylene and alkenes with

1242-402: The early 1960s, Union Carbide Corporation began mining a newly identified outcrop of chrysotile asbestos fibers near King City and New Idria, California . These fibers were sold under the brand name "Calidria", a combination of "Cal" and "Idria", and sold in large quantities for a wide variety of purposes, including additives for joint compound or drywall accessory products. Union Carbide sold

1288-431: The exterior of the catalyst crystallites. Some titanium atoms in these crystallites react with organoaluminum cocatalysts with the formation of Ti–C bonds. The polymerization reaction of alkenes occurs similarly to the reactions in metallocene catalysts: The two chain termination reactions occur quite rarely in Ziegler–Natta catalysis and the formed polymers have a too high molecular weight to be of commercial use. To reduce

1334-512: The incident, organizations representing the victims in Bhopal filed a U.S. $ 10 billion injury claim against Union Carbide. Additionally, the Government of India filed its own $ 3.3 billion claim against the company. Union Carbide's response was an offer in the range of $ 300-$ 350 million. In 1989 the company paid $ 470 million to the Indian government as a final settlement. Broken down, the total cost of

1380-439: The isotactic polymers, all stereogenic centers CHR share the same configuration. The stereogenic centers in syndiotactic polymers alternate their relative configuration. A polymer that lacks any regular arrangement in the position of its alkyl substituents (R) is called atactic. Both isotactic and syndiotactic polypropylene are crystalline, whereas atactic polypropylene, which can also be prepared with special Ziegler–Natta catalysts,

1426-583: The largest-volume commodity plastics as well as the largest-volume commodity chemicals in the world. In the early 1950s workers at Phillips Petroleum discovered that chromium catalysts are highly effective for the low-temperature polymerization of ethylene, which launched major industrial technologies culminating in the Phillips catalyst . A few years later, Ziegler discovered that a combination of titanium tetrachloride (TiCl 4 ) and diethylaluminium chloride (Al(C 2 H 5 ) 2 Cl) gave comparable activities for

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1472-425: The mine to its employees under the name KCAC ("King City Asbestos Mine") in the 1980s, but it only operated for a few more years. Union Carbide India Limited , owned by Union Carbide (50.9%) and Indian investors (49.1%), operated a pesticide plant in Bhopal , the capital of Madhya Pradesh . This plant was opened in 1969. The pesticides and herbicides they produced were created from a insecticide carbaryl , which

1518-412: The modern petrochemical industry . The company divested consumer products businesses Eveready and Energizer batteries, Glad bags and wraps, Simoniz car wax and Prestone antifreeze . The company divested other businesses before being acquired by Dow including electronic chemicals, polyurethane intermediates, industrial gases (Linde) and carbon products. The Union Carbide and Carbon Corporation

1564-585: The molecular weight, hydrogen is added to the polymerization reaction: Another termination process involves the action of protic (acidic) reagents, which can be intentionally added or adventitious. Union Carbide Union Carbide Corporation ( UCC ) is an American chemical company. UCC is a wholly owned subsidiary (since February 6, 2001) of Dow Chemical Company . Union Carbide produces chemicals and polymers that undergo one or more further conversions by customers before reaching consumers. Some are high-volume commodities and others are specialty products meeting

1610-665: The needs of smaller markets. Markets served include paints and coatings, packaging, wire and cable, household products, personal care, pharmaceuticals, automotive, textiles, agriculture, and oil and gas. The company is a former component of the Dow Jones Industrial Average . Founded in 1917 as the Union Carbide and Carbon Corporation , from a merger with National Carbon Company , the company's researchers developed an economical way to make ethylene from natural gas liquids, such as ethane and propane , giving birth to

1656-448: The particle bed in the reactor was either not fluidized or not fully fluidized. In 1968, the first gas-phase fluidized-bed polymerization process, the Unipol process, was commercialized by Union Carbide to produce polyethylene. In the mid-1980s, the Unipol process was further extended to produce polypropylene . In the 1970s, magnesium chloride (MgCl 2 ) was discovered to greatly enhance

1702-470: The production of polyethylene. Natta used crystalline α-TiCl 3 in combination with Al(C 2 H 5 ) 3 to produce first isotactic polypropylene . Usually Ziegler catalysts refer to titanium -based systems for conversions of ethylene and Ziegler–Natta catalysts refer to systems for conversions of propylene . Also, in the 1960s, BASF developed a gas-phase, mechanically-stirred polymerization process for making polypropylene . In that process,

1748-483: The purchase of Carbide in 1999 for $ 8.89 billion in stock. The deal was consummated in 2001 and valued at $ 11.6 billion. The Hawks Nest Tunnel disaster took place between 1927 and 1932 in a West Virginia tunnel project led by Union Carbide. During the construction of the tunnel, workers found the mineral silica and were asked to mine it for use in electroprocessing steel. The workers were not given masks or breathing equipment to use while mining, despite best practices at

1794-533: The settlement to Union Carbide's expenses was 43 cents per share, an amount criticized by some for its comparison to the annual report post-settlement declaring earnings per share. In that 1988 report, Union Carbide claimed to have had its best year yet, citing a record $ 4.88 earnings per share (this figure included the 43 cents per share charge from the Bhopal settlement). After the settlement, Union Carbide’s parent company divested its entire stake in UCIL. Carbide insists

1840-425: The structures of active catalysts have been significantly broadened to include nitrogen-based ligands. These catalysts are metallocenes together with a cocatalyst, typically MAO, −[O−Al(CH 3 )] n −. The idealized metallocene catalysts have the composition Cp 2 MCl 2 (M = Ti, Zr , Hf ) such as titanocene dichloride . Typically, the organic ligands are derivatives of cyclopentadienyl . In some complexes,

1886-475: The time. Due to silica dust exposure, many workers developed silicosis , a debilitating lung disease. According to a marker on site, there were 109 admitted deaths. A congressional hearing placed the death toll at 476, but a book published by epidemiologist Martin Cherniack, and as stated by the U.S. National Park Service, estimated the death toll to be 764, making it America's deadliest industrial disaster. In

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1932-402: The titanium compounds and MgCl 2 are packed into the silica pores. All these catalysts are activated with organoaluminum compounds such as Al(C 2 H 5 ) 3 . All modern supported Ziegler–Natta catalysts designed for polymerization of propylene and higher 1-alkenes are prepared with TiCl 4 as the active ingredient and MgCl 2 as a support. Another component of all such catalysts

1978-494: The two cyclopentadiene (Cp) rings are linked with bridges, like −CH 2 −CH 2 − or >SiPh 2 . Depending on the type of their cyclopentadienyl ligands, for example by using an ansa -bridge , metallocene catalysts can produce either isotactic or syndiotactic polymers of propylene and other 1-alkenes. Ziegler–Natta catalysts of the third class, non-metallocene catalysts, use a variety of complexes of various metals, ranging from scandium to lanthanoid and actinoid metals, and

2024-455: The usual rules, polyvinyl alcohol , (CH 2 CHOH ) n , is produced by hydrolysis of polyvinyl acetate. Vinyl alcohol is not sufficiently stable to undergo polymerization. Vinyl polymers are subject of several structural variations, which greatly expands the range of polymers and their applications. With the exception of polyethylene, vinyl polymers can arise from head-to-tail linking of monomers, head-to-head combined with tail-to-tail, or

2070-810: Was completed in August 2009, Homebush Bay sediments in August 2010, and the Union Carbide site in March 2011. The cost of the remediation work was $ 35M for the Allied Feeds site, and $ 100 million for Union Carbide site and Homebush Bay sediments. The former Union Carbide headquarters building, at 270 Park Avenue in New York City, was a 52-story modernist office building designed by architectural firm Skidmore, Owings & Merrill and completed in 1960. The company relocated its headquarters to Danbury, Connecticut in 1983, to

2116-750: Was formed on November 1, 1917, from the merger of the Union Carbide Company founded in 1898, the National Carbon Company founded in 1886, Linde Air Products Company , a maker of liquid oxygen at Buffalo confiscated from Gesellschaft für Linde's Eismaschinen AG under the Trading with the Enemy Act of 1917 , and the Prest-O-Lite company, manufacturer of calcium carbide in Indianapolis . In 1920,

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