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CHEMICAL GLOSSARY
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Acetaldehyde
Acetaldehyde is an intermediate formed during the oxidation of ethylene to acetic acid (second
WACKER Process). At WACKER, acetaldehyde was converted into acetic acid, acetic anhydride,
ketene-diketene and ethyl acetate until 2012.
Acetic Acid
Acetic acid is a carboxylic acid. It is a corrosive, colorless liquid and is used in the food and
chemical industries to produce acetic anhydride and diketene, for example. At WACKER, acetic
acid is made to react with ethylene to yield vinyl acetate, which is then polymerized to polyvinyl
acetate.
Acetic Anhydride
Acetic anhydride is formed by elimination of water from acetic acid, and is used to convert alcohols into acetates.
One of its application areas is the production of cellulose acetate and acetyl salicylic acid.
Acetone
Acetone is used as a solvent and a starting material for many organic syntheses. It was Wacker Chemie’s first sales product,
being first marketed in 1916. Produced from acetic acid, its uses included the manufacture of synthetic rubber.
Acetylacetone
Acetylacetone is a starting material used in the synthesis of pharmaceuticals (e.g. the manufacture of sulfonamides) and dyes. It also
serves as a solvent, absorption agent, and extraction agent in the chemical industry and is used to treat metal-containing wastewater.
Acetylene
Acetylene is a colorless gas produced from calcium carbide by WACKER on an industrial scale in Burghausen, Germany, and
Siechnice, Poland. It served as a precursor for the industrial production of key feedstocks, such as chlorinated hydrocarbons, acetic
acid, vinyl acetate and vinyl chloride. Addition of acetic acid to acetylene yields vinyl acetate, which is used to manufacture polyvinyl
acetate.
B
Biotechnology
Biotechnology processes use living cells or enzymes to transform and produce substances.
Depending on the application, a distinction is made between red, green and white biotechnology.
Red biotechnology: medical-pharmaceutical applications. Green biotechnology: agricultural
applications. White biotechnology: biotech-based products and industrial processes, e.g. in the
chemical, textile and food industries.
C
Calcium Carbide (“Carbide”)
Calcium carbide, also known as calcium acetylide, consists of calcium and carbon. It was used in the past to provide the illumination
for cyclists’ and miners’ lamps. It was chiefly used to produce acetylene gas at Wacker Chemie between 1916 and 1968. Acetylene
gas was the primary source of all key products in the company’s founding years. Acetylene is now used by WACKER to produce
specialty chemicals.
Catalysis
Catalysts lower the energy needed to activate a reaction and can boost the rate of the reaction. In a catalyzed reaction, the rate –
but not the position of equilibrium – of the reaction is altered. There are lots of examples of catalysis in nature, in which the catalysts
are often enzymes (biocatalysts).
Cellulose Acetate
Cellulose acetate is one of the oldest thermoplastic polymers. The acetate and triacetate fibers made from it are derivatives of
cellulose, a natural substance. Wacker Chemie produced one such synthetic fiber under the brand name Drawinella. Cellulose acetate
is mostly converted into textile fibers and fabrics (artificial silk) which have the look and feel of natural silk. These materials lend themselves to articles such as raincoats and umbrellas because they exhibit very little swelling and absorption when in contact with water.
Chlorinated Hydrocarbons (CHCs)
Chlorinated hydrocarbons were developed at the Consortium für elektrochemische Industrie in 1903, prior to the founding of Wacker
Chemie. The sales products trichloroethylene and perchloroethylene (WACKER-Tri and WACKER-Per) are non-combustible organic
solvents that superseded mineral spirits, a harmful combustible liquid which was used as a dry-cleaning agent and to degrease metals.
Chlorine
Chlorine never occurs as an in Nature, but always as a compound (e.g. as sodium chloride, better known as rock salt ). Chlorine is
obtained by electrolysis and is highly reactive, and so is used to make chorinated and non-chlorinated compounds. Wacker Chemie
now utilizes the chemical energy of chlorine to produce a large number of silicones, most of which are chlorine-free, and hyperpure
silicon, via intermediates such as chlorosilanes and organochlorosilanes. Hydrogen chloride released during conversion of the intermediates into sales products is recovered and fed back into the integrated chlorine/vinyl chloride production system.
Chlorosilanes
Chlorosilanes are compounds made from silicon and chlorine, and possibly other chemical groups. The semiconductor industry uses
trichlorosilane both to make polysilicon and for the epitaxial deposition of silicon.
Cyclodextrins
Cyclodextrins are a family of compounds composed of ring-shaped sugar molecules. They are
able to encapsulate foreign substances such as fragrances and to release active ingredients at
a controlled rate. Cyclodextrins are produced and marketed by WACKER BIOSOLUTIONS.
Cysteine
Cysteine is a sulfur-containing amino acid. It is considered a non-essential amino acid because it can be formed in the body. It is
used, for example, as an additive in foods and cough mixtures. Cysteine and its derivatives are a business field at WACKER
BIOSOLUTIONS.
Czochralski Process
The bulk of the monocrystalline silicon produced for the semiconductor industry is made by the Czochralski process. This entails
melting polycrystalline silicon in quartz crucibles. A seed crystal made of monocrystalline silicon is introduced into the molten silicon
metal and is rotated while it is slowly pulled out of the melt again. The silicon which crystallizes out from the melt is hyperpure; the
impurities remain in the melt.
D
Dichloroethane
Dichloroethane is a colorless, combustible liquid that is made by the chlorination or oxychlorination of ethylene. It can be converted
into vinyl chloride and hydrogen chloride. Vinyl chloride is the starting product for the production of polyvinyl chloride (PVC), which
was one of the key products made by WACKER from 1935 to 2000.
Diketene
Diketene is a reactive, colorless liquid that serves as intermediate in the production of pharmaceuticals, insecticides and dyes.
Dimethyldichlorosilane
Dimethyldichlorosilane (Silane M2) is the principal product of the Müller-Rochow direct synthesis of methylchlorosilanes. It is
converted into silicone fluids and silicone polymers.
Dispersible Polymer Powders
Dispersible polymer powders are made by spray-drying aqueous dispersions. VINNAPAS® polymer powders from WACKER serve
as binders in the construction industry, e.g. for tile adhesives, self-leveling compounds, plasters and mortars in external thermal
insulation composite systems. The powders improve adhesion, cohesion, flexibility and flexural strength, as well as the processing
properties of dry-mix mortars.
Dispersions
A dispersion is a system in which at least one component in finely divided form (disperse phase) is finely dispersed in another phase
(the continuous phase or dispersion medium). VINNAPAS® dispersions are polymer particles that are finely dispersed in water and
are made from vinyl acetate and/or other monomers by emulsion polymerization. They serve as binders for construction products
(e.g. tile adhesives, primers, plasters), as well as for adhesives, paints and fiber-bonding.
Distillation
Distillation is a thermal way of separating the components of liquid mixtures. The process exploits differences in the liquids’ boiling
points.
E
Elastomers
Elastomers are polymers that can be deformed but return to their original shape when the force
is released. While elastic behavior is not affected by the length of time the force acts, it is influenced by temperature. Silicone elastomer is also known as cured (or crosslinked) silicone rubber.
Emulsion
An emulsion is a system comprising two immiscible liquids, one of which (the disperse phase)
is finely dispersed as tiny droplets in the other (dispersion medium) to yield a disperse system.
In a laundry cycle, detergents emulsify grease and dirt in the water, enabling these impurities to
be rinsed out.
Epitaxy
The growth of thin (epitaxial) layers on a substrate (silicon). There are a variety of methods (gas-phase and molecular-beam epitaxy)
to create perfect monocrystals (i.e. no defects) with the desired doping profiles.
ESETEC® Process
ESETEC® is the trade mark for an expression and secretion system developed and patented by WACKER. It is based on an E. coli
K12 bacterial strain which can flush proteins into the culture medium via the outer cell membrane. The result is an efficient, inexpensive
way of manufacturing pharmaceutical proteins. The ESETEC® E. coli secretion technology lends itself to antibody fragment production.
The use of ESETEC® E. coli secretion technology in conjunction with DENSETEC® high-cell-density fermentation can boost product
yield by up to 50 percent.
Ethyl Acetate
Ethyl acetate is a colorless liquid that serves as a solvent, e.g. in the manufacture of adhesives, films, coatings and artificial silk.
Ethylene
Ethylene is produced from crude oil and is a necessary chemical feedstock for a great many polymers, including polyethylene,
polyvinyl acetate and polyvinyl chloride. These polymers have become an essential part of everyday life.
External Thermal Insulation Composite Systems
External thermal insulation composite systems (ETICS) are systems for thermally insulating
buildings and help to save energy. They are made up of a combination of materials: adhesive
mortar, insulation board, base coat, glass fiber mesh and finish coat. VINNAPAS® polymer powders
from WACKER POLYMERS ensure that the insulation material bonds firmly to the mortar and
finish coat. As a result, the insulating system offers greater durability and much more resistance
to weathering and wear.
F
Fine Chemicals
Fine chemicals are usually complex molecules, produced in multi-step syntheses. They primarily serve as building blocks for
medicines, plant-protection agents and specialty chemicals.
Float-Zone Pulling
In float-zone pulling or zone melting, an annular electric induction heater is passed along a polycrystalline silicon ingot, creating a
zone of molten metal. The bulk of the impurities in the ingot dissolve in the melt and move along with it. As with the Czochralski
process, the outcome is a highly pure, monocrystalline silicon ingot. At Siltronic, float-zone pulling is less important than the
Czochralski process.
Fluidized Bed Reactor
Fluidized beds are beds of bulk particles through which a fluid (gas or liquid) flows upward and keeps the particles in suspension
such that they can move freely. At WACKER, fluidized-bed reactors are used, among other things, to synthesize chloromethylsilanes
and trichlorosilane.
G
Granular Polysilicon
The granular form of polysilicon for photovoltaic applications simplifies the handling and metering of polysilicon by virtue of its
free-flow properties.
H
Hybrid Polymers
Silicone hybrid polymers are materials which are created by chemically linking together silicone
building blocks with organic polymer building blocks. They combine the typical properties of
both classes of substance.
Hydrogen Chloride (HCl)
The chemical industry uses HCl to generate valuable intermediates from organic and inorganic
raw materials. Hydrogen chloride, a colorless gas, dissolves in water to yield hydrochloric acid,
which is also used on an industrial scale.
I
Industrial Resins
Polyvinyl acetate and polyvinyl butyral solid resins, e.g. for the production of printing inks, coatings and nonwoven textiles.
K
Ketene
An unstable product obtained from acetic acid by eliminating water at 700 ˚C. This highly reactive product is needed for the
production of specialty chemicals.
M
Metallurgical Silicon
Metallurgical silicon is obtained from quartz and is a precursor for the production of
chlorosilanes. This also makes it a precursor for the manufacture of hyperpure polycrystalline
silicon and silicone products.
Methanol
Methanol or methyl alcohol is the simplest member of the alcohols family. It is needed at
WACKER for the production of methyl chloride (monochloromethane).
Methyl Chloride
Methyl chloride (chloromethane) is produced by chlorination of methanol. Methyl chloride and silicon are the starting materials
for the Müller-Rochow direct synthesis of methylchlorosilanes.
Methyl Resins
Generic term for three-dimensionally crosslinked polymethylsiloxanes used in the construction and other sectors. The properties
of methyl resins can be modified with various additives, such as phenyl silicones.
Methylchlorosilanes
Methylchlorosilanes (MCS) are the principal products yielded by the Müller-Rochow direct synthesis. They are subsequently distilled
to yield the desired pure methylchlorosilanes.
Methyltrichlorosilane
Methyltrichlorosilane (Silane M3) is a minor product of the Müller-Rochow direct synthesis of methylchlorosilanes. It serves to
crosslink silicone chains in silicone resins.
Monomer
A monomer is a molecule which, under the right conditions, can react with molecules that have
the same composition as itself or a different composition to form long chains (polymers).
Monosilicon
Monosilicon is an abbreviation for monocrystalline silicon. Hyperpure monocrystalline
semiconductor-grade silicon is needed for microelectronics applications. In particular, levels of
contamination with elements which also make suitable doping element must be brought down
to below critical values by means of either crucible pulling (Czochralski process) or zone melting.
The term monocrystalline describes the crystal structure: the resultant silicon ingots, which can
weigh up to 450 kg, constitute a single, hyperpure silicon crystal.
Monsanto Process
A process for making acetic acid from methanol and carbon monoxide using a rhodium compound as a catalyst.
Müller-Rochow Synthesis
The Müller-Rochow synthesis is the name for the direct synthesis of methylchlorosilanes from silicon and methyl chloride, and is so
named in honor of its inventors. It ushered in the era of economic polysiloxane (silicone) production after 1940.
O
Oxychlorination
Oxychlorination is a way of incorporating chlorine into an organic compound with the aid of hydrogen chloride in the presence of
oxygen or air. Oxychlorination of ethylene yields vinyl chloride.
P
Perchloroethylene
Perchloroethylene (tetrachloroethene) is a colorless, non-combustible, volatile liquid that serves as a solvent and degreasing agent in
the textiles, sheet film, optical and metal industries.
Pharmaceutical Proteins (Biologics)
Examples of pharmaceutical proteins are enzymes, which by cleaving can transform other proteins into a biologically active form.
Messengers are other pharmaceutical proteins which, after binding to receptors on cell surfaces, can trigger a series of reactions.
Yet a further group comprises antibodies and inhibitors, which are substances that bind to target proteins and render them ineffective.
Polydimethylsiloxane
Polydimethylsiloxanes (PDMS) are members of the silicones family. Silicones are classified as synthetic materials. They can be found
in nearly all areas of everyday life and industry. Their structure can be modified during synthesis and processing in such a way that
they exhibit outstanding properties in many applications.
Polyethylene
Polyethylene is an ethylene-based thermoplastic polymer that is converted into numerous
products, e.g. household goods and packaging.
Polymers
Polymers are long-chain or branched macromolecules (large molecules) that are built up from
building blocks (monomers) of identical or different composition. Polymers can be elongated or
ball-shaped. Plastics such as PE and PVC are polymers.
Polysilicon
Polysilicon is an abbreviation for polycrystalline silicon produced by the WACKER POLYSILICON division. This hyperpure silicon is a
starting material for the production of wafers for the electronics and solar industries.
Polyvinyl Acetate Solid Resins
VINNAPAS® solid resins are homogeneous, colorless, odorless and tasteless resins that pose no known physiological risks. All
VINNAPAS® grades yield clear films with good gloss and excellent adhesion. This is particularly true of the low-viscosity B grades,
which are often preferred for primer coatings or for combinations with other coatings raw materials.
Polyvinyl Acetate
Polyvinyl acetate (PVAc or PVA) is a thermoplastic polymer which serves as a binder in paints and surface coatings and is also used
as a wood glue and adhesive. Other application areas are paper manufacturing and coating, textile impregnation, carpet-backing
coating and the modification of plaster and concrete (VINNAPAS®).
Polyvinyl Alcohol
Polyvinyl alcohol is a water-soluble polymer first produced in 1924 at the Consortium für elektrochemische Industrie by the saponification of polyvinyl esters. It serves in the production of many everyday articles, e.g. adhesives, packaging, PET bottles, shampoos,
and textile fibers.
Polyvinyl Chloride
Polyvinyl chloride (PVC) is a thermoplastic polymer. Thanks to added stabilizers, it can be thermally processed and so molded and
used in technical applications. PVC is used in floor coverings, window frames, piping, and cable insulation.
R
Rock Salt
Rock salt (sodium chloride) is a mineral salt that is mined in underground deposits or is obtained by dissolving a deposit in water and then evaporating the brine (vacuum salt). Sodium
chloride is one of the chemical industry’s most important raw materials; it is also used in the
food sector and for road maintenance in the winter.
S
Semiconductor
Semiconductors are substances whose electrical conductivity is much lower than that of metals but increases dramatically as the
temperature rises. They are non-conductors at absolute zero. These physical properties are needed in the electronics industry to
construct circuits. Semiconductors can be modified for a particular purpose by doping with foreign atoms.
Silanes
Silanes are used as monomers for the synthesis of siloxanes and are sold directly as reagents or raw materials. Application areas
include surface treatment, adhesive primers for coatings as well as pharmaceutical syntheses.
Silanes, Organofunctional
A name for silanes that, in addition to hydrolyzable substituents, bear organofunctional groups such as aminoalkyl or chloroalkyl.
These organofunctional groups are used for tailoring particular surface properties, crosslinking polymers and coupling organic
materials to inorganic or metallic surfaces.
Silica – Pyrogenic, Fumed (WACKER HDK®)
Pyrogenic silica is generated by flame hydrolysis and has a virtually pore-free surface. Silicas are hydrophilic when formed initially,
due to free silanol groups on the surface. But they can be rendered hydrophobic by treatment with chlorosilanes. Applications
include reinforcing fillers for rubber compounds and sealants, matting of paints, and toothpaste additives.
Silica
Synthetic silicas are made from chlorosilanes and from water glass. They are known as either precipitated silicas or pyrogenic silicas
(WACKER HDK®) depending on the chosen production method.
Silicates
Silicates are salts and esters of silicic acid. More than 90 percent of the earth’s crust consists of silicate minerals. Tetraethyl silicate
is an important product for the coatings industry.
Silicon Carbide
Silicon carbide is a crystalline compound of silicon and carbon. Its physical properties are similar to those of diamond, it has a high
melting point and is very hard. It is used as an abrasive and as an ingredient of refractory materials. Metallurgical silicon carbide is an
alloying material for cast iron.
Silicon Wafer
A silicon wafer is a disc which is between 200 and 800 µm thick. In the semiconductor industry,
wafers are used to make chips for producing semiconductor devices, e.g. for integrated circuits
and discrete devices.
Silicon
After oxygen, silicon is the most common element in the earth’s crust. In Nature, it occurs without exception in the form of
compounds, chiefly silicon dioxide and silicates. Silicon is obtained through energy-intensive reaction of quartz sand with carbon
and is the most important raw material in the electronics industry.
Silicone Fluids
Silicone fluids are polymers which are based on linear silicon-oxygen structural units and whose chains can vary in length from two
to over 1,000 silicon atoms. Compared with that of mineral oils, the viscosity of silicone fluids remains relatively constant over a wide
temperature range. Application areas include hydraulic fluids, release agents, high-temperature lubricants, polishes and conditioners,
and cosmetics additives.
Silicone Resins
Silicone resins range from relatively low-molecular precursors to high-molecular, extensively crosslinked resinous solids having all
manner of different structures. Their compatibility with many different types of organic polymers can be exploited to optimize
properties such as curing behavior, flexibility, adhesive properties and weathering resistance. Typical areas of application include
high-temperature coatings, molding compounds, laminates and casting resins (for the electronics industry).
Silicone Rubber – HTV
HTV silicone rubbers are plastic materials. They very often contain organic peroxides for initiating crosslinking. Crosslinking is
conducted at high temperature and yields heat-resistant products called elastomers that are elastic at temperatures between -40
and 250 °C, and are converted into high-quality sealing and damping parts, electrically insulating parts, cable jackets and the like.
Silicone Rubber – LSR
Liquid silicone rubber (LSR) is a crosslinkable silicone composition that is processed on injection molding machines. Self-adhesive
LSR silicone rubber safeguards reliable parts production and ensures that the end products are fully functional. Consequently, LSR
injection molding lends itself especially to the production of automotive parts. Preferred applications include membranes, weatherresistant and contamination-resistant parts, spark plug boots, and molded seals.
Silicone Rubber – RTV
Silicone rubber grades that vulcanize at room temperature; they can be divided into one- and
two-component systems. One-component systems (RTV-1) polymerize slowly at room temperature under the influence of humidity (condensation crosslinking). Two-component systems
(RTV-2) crosslink by either condensation or addition (typically by reaction between an Si-H
crosslinker and vinyl groups in the presence of a metal catalyst).
Silicone Rubber
In chemical terms, silicone rubber is derived from linear siloxanes that may bear hydroxyl, vinyl or other reactive groups. These
polymers can be crosslinked in a variety of ways to produce more or less loose-mesh structures that exhibit pronounced elastic
behavior. Silicone rubber owes its characteristic properties of elasticity, shock absorption and strength to added active fillers,
especially pyrogenic silica. Typical applications are found in the automotive, electrical, chemical and mechanical engineering sectors.
Silicones
Silicones is the generic term for polymers consisting of silicon-oxygen structural units that bear organic groups. In accordance with
the properties conferred by their structure, silicones can be fluids, resins or rubber grades. Silicones are characterized by a myriad of
outstanding properties. Typical areas of application include construction, the electrical and electronics industries, shipping and transportation, textile finishing and paper coating.
Siloxanes
Siloxanes is the systematic name given to compounds in which silicon atoms are linked together via oxygen atoms, with the remaining valencies being occupied by hydrogen or organic groups. Siloxanes are the building blocks for the polymers (polysiloxane and
polyorganosiloxane) upon which silicones are based.
Sodium Hydroxide
Sodium hydroxide is a by-product of the chlor-alkali electrolysis of rock salt. It is one of the most widely employed laboratory and
industrial chemicals and is needed, for example, in the aluminum, paper and chemical industries.
Spray Dryer
A device for drying aqueous polymer dispersions to produce a free-flowing powder. There are two types of dryer. In the first type,
the dispersion is sprayed through dual-material nozzles under high air pressure or is atomized under high pump pressure via high
pressure nozzles. In the second type, atomization is effected by means of a rotating disc.
Surface Coating Resins
Generic name for natural resins or synthetic products widely used in surface coatings.
T
Tetrachloroethane
Tetrachloroethane is a chemical compound and a member of the chlorinated hydrocarbons family. It was formerly used as an
intermediate in the manufacture of trichloroethylene.
Tetrachlorosilane
Tetrachlorosilane is a clear, colorless liquid that reacts highly exothermically with water. It is
formed by the decomposition of trichlorosilane to hyperpure silicon and is a key feedstock for
the production of pyrogenic silica (HDK®).
Trichloroethylene
Trichloroethylene is a clear, colorless, non-flammable liquid. On account of its good degreasing
properties, it was incorporated into detergents for cleaning molds and rolls in the printing industry, into cleaning agents for machines
used in metal processing factories, and into dry-cleaning agents and textile-processing chemicals.
Trichlorosilane
Trichlorosilane (TCS) is a clear, colorless liquid that enters into a highly exothermic reaction with water. This silicon compound is
important for the production of organofunctional silanes and the production of polysilicon.
V
VINNAPAS®
VINNAPAS® is the WACKER brand name for its dispersions and dispersible polymer powders, as well as solid resins and resin
solutions. VINNAPAS® dispersions and dispersible polymer powders are chiefly used as polymeric binders in the construction
industry and many other application areas. VINNAPAS® solid resins are a key component of low-profile additives, adhesives, paints
and other applications.
Vinyl Acetate
Vinyl acetate is used in the manufacture of polyvinyl acetate, vinyl acetate copolymers and
polyvinyl alcohol. These polymers, variously added to dispersions, dispersible polymer powders,
solid resins, and solutions, serve as binders for the construction and paints and coatings sectors,
as well as for raw materials for the adhesives, paper and textiles industry.
Vinyl Acetate-Ethylene Copolymer (VAE) Dispersions
The term vinyl acetate-ethylene (VAE) copolymer refers to a family of polymers derived from the monomers vinyl acetate and
ethylene. These serve as binders in industrial sectors, such as construction, adhesives, paints, nonwovens, carpet and paper-making.
Vinyl Chloride
Vinyl chloride (VC) is the starting substance for the production of polyvinyl chloride (PVC).
W
Wacker Kupferkalk (copper lime)
Copper lime – a neutral copper oxychloride that proved to be a particularly effective fungicide, especially for hop crops and viniculture.
Production ceased in the 1990s.
WACKER Process
The first WACKER Process was the production of acetaldehyde from acetylene. It was developed at the Consortium in 1913, which
also developed the second WACKER Process in 1957. This produces acetaldehyde from ethylene in the presence of a palladium (II)
chloride catalyst. Both processes found their way into organic chemistry textbooks and were licensed all around the world.