In polymer chemistry, a comonomer refers to a polymerizable precursor to a copolymer aside from the principal monomer. In some cases, only small amounts of a comonomer are employed, in other cases substantial amounts of comonomers are used. Furthermore, in some cases, the comonomers are statistically incorporated within the polymer chain, whereas in other cases, they aggregate. The distribution of comonomers is referred to as the "blockiness" of a copolymer.
1-Octene, 1-hexene, and 1-butene are used comonomers in the manufacture of polyethylenes. The advantages to such copolymers has led to a focus on catalysts that facilitate the incorporation of these comonomers, e.g., constrained geometry complexes. [1]
Comonomers are often employed to improve the plastification of polymeric materials, i.e. the flexibility of the polymer. Unlike traditional plasticizers, comonomers are not leachable.
In other cases, comonomers are used to introduce crosslinking. Divinylbenzene, for example, when copolymerized with styrene, gives a crosslinked polystyrene. [2]
The homopolymers of acrylate esters (e.g., butyl acrylate) have few applications. Copolymers however have many applications/ They are produced by copolymerization of alkyl acrylates and one or more of the following comonomers methyl methacrylate, styrene, acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, and butadiene. [3]
In chemistry, a monomer is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging (plastic bags, plastic films, geomembranes and containers including bottles, etc.). As of 2017, over 100 million tonnes of polyethylene resins are being produced annually, accounting for 34% of the total plastics market.
Polyacrylonitrile (PAN), also known as polyvinyl cyanide and Creslan 61, is a synthetic, semicrystalline organic polymer resin, with the linear formula (C3H3N)n. Though it is thermoplastic, it does not melt under normal conditions. It degrades before melting. It melts above 300 °C if the heating rates are 50 degrees per minute or above. Almost all PAN resins are copolymers made from mixtures of monomers with acrylonitrile as the main monomer. It is a versatile polymer 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.
Acrylates (IUPAC: prop-2-enoates) are the salts, esters, and conjugate bases of acrylic acid. The acrylate ion is the anion CH2=CHCOO−. Often, acrylate refers to esters of acrylic acid, the most common member being methyl acrylate. These acrylates contain vinyl groups. These compounds are of interest because they are bifunctional: the vinyl group is susceptible to polymerization and the carboxylate group carries myriad functionalities. Methacrylates (CH2=C(CH3)CO2R) and cyanoacrylates (CH2=C(CN)CO2R) are usually considered separately even though they share several properties. Acrylate can refer to polyacrylates prepared through the polymerization of the vinyl groups of acrylate monomers.
In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are sometimes called bipolymers. Those obtained from three and four monomers are called terpolymers and quaterpolymers, respectively. Copolymers can be characterized by a variety of techniques such as NMR spectroscopy and size-exclusion chromatography to determine the molecular size, weight, properties, and composition of the material.
In polymer chemistry, anionic addition polymerization is a form of chain-growth polymerization or addition polymerization that involves the polymerization of monomers initiated with anions. The type of reaction has many manifestations, but traditionally vinyl monomers are used. Often anionic polymerization involves living polymerizations, which allows control of structure and composition.
In polymer chemistry, vinyl polymers are a group of polymers derived from substituted vinyl monomers. Their backbone is an extended alkane chain [−CH2−CHR−]. In popular usage, "vinyl" refers only to polyvinyl chloride (PVC).
A polyolefin is a type of polymer with the general formula (CH2CHR)n where R is an alkyl group. They are usually derived from a small set of simple olefins (alkenes). Dominant in a commercial sense are polyethylene and polypropylene. More specialized polyolefins include polyisobutylene and polymethylpentene. They are all colorless or white oils or solids. Many copolymers are known, such as polybutene, which derives from a mixture of different butene isomers. The name of each polyolefin indicates the olefin from which it is prepared; for example, polyethylene is derived from ethylene, and polymethylpentene is derived from 4-methyl-1-pentene. Polyolefins are not olefins themselves because the double bond of each olefin monomer is opened in order to form the polymer. Monomers having more than one double bond such as butadiene and isoprene yield polymers that contain double bonds (polybutadiene and polyisoprene) and are usually not considered polyolefins. Polyolefins are the foundations of many chemical industries.
Poly(methyl acrylate) (PMA) is a family of organic polymers with the formula (CH2CHCO2CH3)n. It is a synthetic acrylate polymer derived from methyl acrylate monomer. The polymers are colorless. This homopolymer is far less important than copolymers derived from methyl acrylate and other monomers. PMA is softer than polymethyl methacrylate (PMMA), It is tough, leathery, and flexible.
An acrylate polymer is any of a group of polymers prepared from acrylate monomers. These plastics are noted for their transparency, resistance to breakage, and elasticity.
1,1-Dichloroethene, commonly called 1,1-dichloroethylene or vinylidene chloride or 1,1-DCE, is an organochloride with the molecular formula C2H2Cl2. It is a colorless liquid with a sharp odor. Like most chlorocarbons, it is poorly soluble in water, but soluble in organic solvents. 1,1-DCE was the precursor to the original clingwrap, Saran, for food, but this application has been phased out.
Synthetic resins are industrially produced resins, typically viscous substances that convert into rigid polymers by the process of curing. In order to undergo curing, resins typically contain reactive end groups, such as acrylates or epoxides. Some synthetic resins have properties similar to natural plant resins, but many do not.
Ethyl acrylate is an organic compound with the formula CH2CHCO2CH2CH3. It is the ethyl ester of acrylic acid. It is a colourless liquid with a characteristic acrid odor. It is mainly produced for paints, textiles, and non-woven fibers. It is also a reagent in the synthesis of various pharmaceutical intermediates.
Vinyl bromide is a simple vinyl halide. It is a colorless liquid. It is produced from ethylene dibromide. It is mainly used as a comonomer to confer fire retardant properties to acrylate polymers.
Methyl acrylate is an organic compound, more accurately the methyl ester of acrylic acid. It is a colourless liquid with a characteristic acrid odor. It is mainly produced to make acrylate fiber, which is used to weave synthetic carpets. It is also a reagent in the synthesis of various pharmaceutical intermediates. Owing to the tendency of methyl acrylate to polymerize, samples typically contain an inhibitor such as hydroquinone.
2-Vinylpyridine is an organic compound with the formula CH2CHC5H4N. It is a derivative of pyridine with a vinyl group in the 2-position, next to the nitrogen. It is a colorless liquid, although samples are often brown. It is used industrially as a precursor to specialty polymers and as an intermediate in the chemical, pharmaceutical, dye, and photo industries. Vinylpyridine is sensitive to polymerization. It may be stabilized with a free radical inhibitor such as tert-butylcatechol. Owing to its tendency to polymerize, samples are typically refrigerated.
4-Vinylbenzyl chloride is an organic compound with the formula ClCH2C6H4CH=CH2. It is a bifunctional molecule, featuring both vinyl and a benzylic chloride functional groups. It is a colorless liquid that is typically stored with a stabilizer to suppress polymerization.
Vinyl propionate is the organic compound with the formula CH3CH2CO2CH=CH2. This colorless liquid is the ester of propionic acid and vinyl alcohol. It is used to produce poly(vinyl propionate) as well as copolymers with acrylate esters, vinyl chloride, and vinyl acetate, some of which are used in paints. The compound resembles vinyl acetate.
Poly(ethyl acrylate) (PEA) is a family of organic polymers with the formula (CH2CHCO2CH2CH3)n. It is a synthetic acrylate polymer derived from ethyl acrylate monomer. The polymers are colorless. This homopolymer is far less important than copolymers derived from ethyl acrylate and other monomers. It has a low glass-transition temperature about -8 °C (20 °C.
Poly(ethyl acrylate) (PBA) is a family of organic polymers with the formula (CH2CHCO2CH2CH2CH2CH3)n. It is a synthetic acrylate polymer derived from butyl acrylate monomer. The polymers are colorless. This homopolymer is far less important than copolymers derived from methyl acrylate and other monomers. It has a low glass-transition temperature about -43 °C (20 °C.