Polymers in the context of "Hydrogen cyanide"

Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and preventing corrosion.

In the most common use of the word, this means electrochemical oxidation of a metal reacting with an oxidant such as oxygen (O₂, gaseous or dissolved), or H₃O ions ( H, hydrated protons) present in aqueous solution. Rusting, the formation of red-orange iron oxides, is perhaps the most familiar example of electrochemical corrosion. This type of corrosion typically produces oxides or salts of the original metal and results in a distinctive coloration. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although, in this context, the term degradation is more common. Corrosion degrades the useful properties of materials and structures including mechanical strength, appearance, and permeability to liquids and gases. Corrosive is distinguished from caustic: the former implies mechanical degradation, the latter chemical.

Nucleotides are organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver.

Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine, and thymine; in RNA, uracil is used in place of thymine.

A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nucleotides. By convention, sequences are usually presented from the 5' end to the 3' end. For DNA, with its double helix, there are two possible directions for the notated sequence; of these two, the sense strand is used. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure.

The sequence represents genetic information. Biological deoxyribonucleic acid represents the information which directs the functions of an organism.

Microstructure is the very small-scale structure of a material, defined as the structure of a prepared surface of material as revealed by an optical microscope above 25× magnification. The microstructure of a material (e.g. metals, polymers, ceramics, or composites) can strongly influence physical properties such as strength, toughness, ductility, hardness, corrosion resistance, high/low temperature behaviour or wear resistance. These properties in turn govern the application of these materials in industrial practice.

Microstructure at scales smaller than can be viewed with optical microscopes is often called nanostructure, while the structure in which individual atoms are arranged is known as crystal structure. The nanostructure of biological specimens is referred to as ultrastructure.

An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula C
₂H
₃O
₂. The neutral molecules formed by the combination of the acetate ion and a positive ion (called a cation) are also commonly called "acetates" (hence, acetate of lead, acetate of aluminium, etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic anion CH
₃CO
₂, or CH
₃COO
.

Most of the approximately 5 million tonnes of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In nature, acetate is the most common building block for biosynthesis.

Specialty chemicals (also called specialties or effect chemicals) are particular chemical products that provide a wide variety of effects on which many other industry sectors rely. Some of the categories of speciality chemicals are adhesives, agrichemicals, cleaning materials, colors, cosmetic additives, construction chemicals, elastomers, flavors, food additives, fragrances, industrial gases, lubricants, paints, polymers, surfactants, and textile auxiliaries. Other industrial sectors such as automotive, aerospace, food, cosmetics, agriculture, manufacturing, and textiles are highly dependent on such products.

Speciality chemicals are materials used on the basis of their performance or function. Consequently, in addition to "effect" chemicals they are sometimes referred to as "performance" chemicals or "formulation" chemicals. They can be unique molecules or mixtures of molecules known as formulations. The physical and chemical characteristics of the single molecules or the formulated mixtures of molecules and the composition of the mixtures influences the performance end product. In commercial applications the companies providing these products more often than not provide targeted customer service to innovative individual technical solutions for their customers. This is a differentiating component of the service provided by speciality chemical producers when they are compared to the other sub-sectors of the chemical industry such as fine chemicals, commodity chemicals, petrochemicals and pharmaceuticals.