Copolymer in the context of "Polyurethane"

Polylactic acid, also known as poly(lactic acid) or polylactide (PLA), is a plastic material. As a thermoplastic polyester (or polyhydroxyalkanoate) it has the backbone formula (C
₃H
₄O
₂)
_n or [–C(CH
₃)HC(=O)O–]
_n. PLA is formally obtained by condensation of lactic acid C(CH
₃)(OH)HCOOH with loss of water (hence its name). It can also be prepared by ring-opening polymerization of lactide [–C(CH
₃)HC(=O)O–]
₂, the cyclic dimer of the basic repeating unit. Often PLA is blended with other polymers. PLA can be biodegradable or long-lasting, depending on the manufacturing process, additives and copolymers.

Synthetic resin is an industrially produced, typically viscous substance that converts into rigid polymers by the process of curing. They are formed by the reaction of dibasic organic acids and polyhydric alcohols.. In order to undergo curing, resins typically contain reactive groups, such as acrylates or epoxides. Some synthetic resins have properties similar to natural plant resins, but many do not.

Synthetic resins are of several classes. Some are manufactured by esterification of organic compounds. Some are thermosetting plastics in which the term "resin" is loosely applied to the reactant(s), the product, or both. "Resin" may be applied to one or more monomers in a copolymer, the other being called a "hardener", as in epoxy resins. For thermosetting plastics that require only one monomer, the monomer compound is the "resin". For example, liquid methyl methacrylate is often called the "resin" or "casting resin" while in the liquid state, before it polymerizes and "sets". After setting, the resulting poly(methyl methacrylate) (PMMA) is often renamed "acrylic glass" or "acrylic". (Trade names include Plexiglas and Lucite).

Flame retardants are a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source and prevent or slow the further development of flames by a variety of different physical and chemical mechanisms. They may be added as a copolymer during the polymerisation process, or later added to the polymer at a moulding or extrusion process or (particularly for textiles) applied as a topical finish. Mineral flame retardants are typically additive, while organohalogen and organophosphorus compounds can be either reactive or additive.

Thermoplastic elastomers (TPE), sometimes referred to as thermoplastic rubbers (TPR), are a class of copolymers or a physical mix of polymers (usually a plastic and a rubber) that consist of materials with both thermoplastic and elastomeric properties.

While most elastomers are thermosets, thermoplastic elastomers are not, in contrast making them relatively easy to use in manufacturing, for example, by injection moulding. Thermoplastic elastomers show advantages typical of both rubbery materials and plastic materials. The benefit of using thermoplastic elastomers is the ability to stretch to moderate elongations and return to its near original shape creating a longer life and better physical range than other materials.

Polyacrylonitrile (PAN) is a synthetic, semicrystalline organic polymer resin, with the linear formula (CH₂CHCN)_n. Almost all PAN resins are copolymers with acrylonitrile as the main monomer. PAN is used to produce large variety of products including ultra filtration membranes, hollow fibers for reverse osmosis, fibers for textiles, and oxidized PAN fibers. PAN fibers are the chemical precursor of very high-quality carbon fiber. PAN is first thermally oxidized in air at 230 °C to form an oxidized PAN fiber and then carbonized above 1000 °C in inert atmosphere to make carbon fibers found in a variety of both high-tech and common daily applications such as civil and military aircraft primary and secondary structures, missiles, solid propellant rocket motors, pressure vessels, fishing rods, tennis rackets and bicycle frames. It is a component repeat unit in several important copolymers, such as styrene-acrylonitrile (SAN) and acrylonitrile butadiene styrene (ABS) plastic.

A modacrylic is a synthetic copolymer. Modacrylics are soft, strong, resilient and dimensionally stable. They can be easily dyed, show good press and shape retention, and are quick to dry. They have outstanding resistance to chemicals and solvents, are not attacked by moths or mildew, and are nonallergenic. Among their uses are in apparel linings, furlike outerwear, paint-roller covers, scatter rugs, carpets, and work clothing and as hair in wigs.

Commercial production of modacrylic fiber began in 1949 by Union Carbide Corporation in the United States. Modacrylic and acrylic fibers are similar in composition and at one time were in the same category. In 1960 the Federal Trade Commission decided to separate the two fibers and establish a category for each.

Acrylonitrile butadiene styrene (ABS) (chemical formula (C₈H₈)_x·​(C₄H₆)_y·​(C₃H₃N)_z ) is a common thermoplastic polymer. Its glass transition temperature is approximately 105 °C (221 °F). ABS is amorphous and therefore has no true melting point.

ABS is a terpolymer made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. The proportions can vary from 15% to 35% acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene. The result is a long chain of polybutadiene crisscrossed with shorter chains of poly(styrene-co-acrylonitrile). The nitrile groups from neighboring chains, being polar, attract each other and bind the chains together, making ABS stronger than pure polystyrene. The acrylonitrile also contributes chemical resistance, fatigue resistance, hardness, and rigidity, while increasing the heat deflection temperature. The styrene gives the plastic a shiny, impervious surface, as well as hardness, rigidity, and improved processing ease. The polybutadiene, a rubbery substance, provides toughness and ductility at low temperatures, at the cost of heat resistance and rigidity. For the majority of applications, ABS can be used between −20 and 80 °C (−4 and 176 °F), as its mechanical properties vary with temperature. The properties are created by rubber toughening, where fine particles of elastomer are distributed throughout the rigid matrix.

Spandex, Lycra, or elastane is a synthetic fiber known for its exceptional elasticity. It is a polyether-polyurea copolymer that was invented in 1958 by chemist Joseph Shivers at DuPont.