Finally, the polymers, in the form of a resin a mass of polymer chains go to a plastics factory, where additives give the plastic the desired properties.
In addition polymerisation—you guessed it—monomers are simply added together in a repeating pattern. This results in no other, additional, substance being created. The other way in which polymers can be created is called condensation polymerisation.
In this process, when each monomer is added to the chain, an additional, small molecule—such as water—is created as a by-product. Nylon and polyester are made this way. Addition polymerisation relies on a monomer with a double bond connecting two carbon atoms. A molecule called a free radical is introduced, which causes the double bond to open up and link with the next monomer molecule.
The polymer chain forms when the same basic unit is repeated over and over in a regular chain structure. This means that polymers can be made faster, cheaper, cleaner and with greater control of the final product. Polyethylene is the simplest synthetic polymer. Other polymers can be made of two or more different monomers. Polyethylene is formed when many thousands of ethylene molecules are joined end to end. This causes it to cleave in two, creating a free radical. A free radical is a molecule with a single unpaired electron.
Or, to get technical, a molecule with an unpaired electron in its outermost valence shell is an unstable molecule. Either way, the lone electron is going to want to pair up with another electron. It attacks the double bond joining the two carbons in the ethylene molecule and swipes an electron. The other carbon, previously happily paired, now has an unpaired electron.
It has become a free radical, with an unpaired electron eager to join up with another to make a pair. A second ethylene molecule is introduced.
The newly created free radical breaks the carbon-to-carbon bond, swiping an electron, and creating a new free radical with a single unpaired electron on the end. This continues, as a chain reaction, with a long chain forming as more ethylene molecules are added. The transfer of risk and costs commences from delivery to the buyer. Unless expressed otherwise, unloading at the destination is at the buyer's cost.
If the parties wish to diminish the sellers obligations, such as the payment of certain expenses due to importation, they will have to specify it. This term represents the seller's maximal obligation.
Debottlenecking - Increasing production capacity of existing facilities through the modification of existing equipment to remove throughput restrictions.
Debottlenecking generally increases capacity for a fraction of the cost of building new facilities. Decommission - To remove from service. Degradable - Plastics which will environmentally decompose to a powder or liquid form through biodegradation, volubility and photodegradation mechanisms. Degree of polymerization - An expression for the number of monomer units in a polymer chain.
Delta - An increment of a variable. In plastics, it usually refers to the difference between two grades of the same polymer. Demand - The amount of product being requested by potential customers. Total demand in a country is the combination of domestic demand and exports. High demand with a combination of low supply will equate to very high prices, while low demand with ample supply will help to push prices down as suppliers try to move inventory. Density - The mass of a substance per unit volume.
It is an important parameter for polyethylene, affecting most end product physical properties. Derivative - Chemical compound derived or made from other chemicals. Polyethylene is an ethylene derivative. Destocking - A process whereby converters work off their stocks in the expectation that they can replace the stock later at a cheaper price.
Rule of Thumb - In the plastics industry, destocking activities can greatly affect prices. If prices appear to be falling and converters choose to use their stocks rather than purchase new raw materials then demand for the raw material falls and this helps to push down the price of the raw material even further. Distillation Unit Atmospheric - The primary distillation unit that processes crude oil including mixtures of other hydrocarbons at approximately atmospheric conditions.
It includes a pipe still for vaporizing the crude oil and a fractionation tower for separating the vaporized hydrocarbon components in the crude oil into fractions with different boiling ranges.
This is done by continuously vaporizing and condensing the components to separate higher boiling point material. The selected boiling ranges are set by the processing scheme, the properties of the crude oil, and the product specifications. Downstream - A relative term, which indicates greater removal from origins than some point of reference. For example, a petrochemical plant which cracks naphtha lies downstream from a refinery. A PE plant lies downstream from a cracker.
The opposite of upstream. Dry Gas - Natural gas composed mainly of methane with only minor amounts of ethane, propane and butane and little or no heavier hydrocarbons in the gasoline range. Elastomer - A polymer that forms a disorganized molecular pile capable of uncoiling and recoiling in response to physical force and its removal.
This ability to yield and recover makes a substance rubbery. Industry turns molecules into flexible, strectchable, compressible, resilient goods. Elastomers are the base material for all rubber products and for many adhesives. Most elastomers, e. Electrochemical Process - The direct process end use in which electricity is used to cause a chemical transformation.
Major uses of electrochemical process occur in the aluminum industry in which alumina is reduced to molten aluminum metal and oxygen, and in the alkalies and chlorine industry, in which brine is separated into caustic soda, chlorine, and hydrogen. Electrochemical Unit ECU - The chlor-alkali process produces chlorine and caustic soda in set ratios of one unit of chlorine and 1. The combination of one unit of chlorine and 1. Electrolysis - The process of decomposing a substance, usually in solution or as a melt by the passage of an electric current.
Element - A substance that is composed of a single type of atom; a substance that cannot be decomposed by a chemical change. Emulsifier - A compound added to a mixture of two immiscible liquids in order to make it an emulsion and not just two layers of liquid lying on top of each other. The emulsifier is usually something like a soap whose molecules have a water-soluble end and an organic-soluble end.
The soap molecules form little balls called micelles, in which the water-soluble ends point out into the water, and the organic-soluble ends point into the inside of the ball. The oil is stabilized in the water by hiding in the center of the micelle. Thus the water and oil stay mixed. Emulsion - A dispersion where a liquid is dispersed in another liquid - for example, milk is an emulsion of oil in water.
Emulsion polymerization - Batch, semi-continuous or continuous. VCM monomer is emulsified in water by means of surface-active agents. The monomer is thus present as droplets and a small fraction is dissolved in micelles. Water-soluble initiator is added and polymerization starts in the micelles. Monomer is added to the latex particles micelles by diffusion from the emulsion droplets through the aqueous phase.
Batch: all components in reactor; polymerization is stopped when the yield is reached. Semi-continuous: emulgator is continuously added during the polymerization. Continuous: water, initiator, monomer and emulgator are added at the top of the reactor. The PVC latex is removed at the bottom of the reactor. The latex is degasified and dried; the resulting solid PVC is stored. End groups - Structural units that terminate polymer chains.
Engineering plastic - A polymer with an appropriate combination of stiffness, toughness, and dimensional stability that is formed into parts such as gears, bearings and casings. Ethane - A normally gaseous straight-chain hydrocarbon, C2H6. It is a colorless, paraffinic gas that boils at a temperature of It is the second most important constituent of natural gas, it also occurs dissolved in petroleum oils and as a by-product of oil refinery operations and of the carbonisation of coal.
Ethane is a major raw material for the huge ethylene petrochemical industry, which produces such products as polyethylene plastic, ethylene glycol, and ethyl alcohol. Ethylene - An olefinic hydrocarbon recovered from refinery processes or petrochemical processes. Ethylene is used as a petrochemical feedstock for numerous chemical applications and the production of consumer goods.
Expanded polystyrene EPS - Expanded polystyrene, manufactured from styrene, is a thermal plastic material supplied to moulders in the form of a polystyrene bead. The beads, which contain a blowing agent, are processed and moulded into low-density foam articles, such as protective packaging, and foam insulation for building and construction.
Exploration - The phase of operations which covers the search for oil or gas by carrying out detailed geological and geophysical surveys followed up where appropriate by exploratory drilling. Extruded polystyrene XPS - Extruded polystyrene, manufactured from polystyrene, is a thermal plastic material manufactured by a variety of extrusion processes.
Polystyrene foam board and extruded foam sheet have properties that make it a frequent choice for thermal insulation, sheathing, roofing and building and construction application. Extruder - A machine for producing more or less continuous lengths of plastic sections. Extrusion - A thermoplastic process whereby pellets, granules, or powder are melted and forced through a die under pressure to form a given, continuous shape.
Typical shapes extruded are flat films and sheets, filaments and fibers, strands for pelletizing, and webs for coating and laminating. The seller's only responsibility is to put the merchandise at the buyer's disposal, on its premises.
The seller is not responsible for loading the goods on the vehicle produced by the buyer, except by a different agreement. The risk transfer takes place at the moment the goods are made available to the buyer. The buyer bears all risks and costs inherent to the transport of the goods, from that point to the destination. This term represents the seller's minimum obligation. Exclusively by sea or by inland waterway. According to this term, the seller's obligations are fulfilled when the goods are placed alongside the ship, on the quay or on barges.
The seller produces the merchandise along with the invoice and the documents specified in the contract, and cleared for export. This is contrary to the Incoterms. The costs and risks are transferred from seller to buyer upon delivery. This means that the buyer must cover the costs and risks of loss or damage to the goods. It is the buyer who designates the ship and pays for maritime freight.
FCA - Free Carrier FCA Aliaga. It is the buyer who chooses the method of transport and the carrier, and who pays for them. The seller fulfils his obligations when he hands the goods over to the carrier designated by the buyer, at the location agreed on in the Incoterm.
The transfer of costs and risks becomes effective from the moment the carrier takes over the merchandise. If the agreed place is the seller's premises , the delivery is done when the goods are loaded on the vehicle of the carrier named by the buyer. If the agreed place isn't the seller's premises , the delivery is done when the goods are made available to the carrier named by the buyer on the loaded vehicle. The seller is responsible, at his own cost and risk, of providing the buyer with all the necessary documentation for exportation licences, customs formalities, Feedstock - The physical components that are combined in production to produce a product.
A product of oil or gas processing suitable for charging to introduction into an upgrading unit for further refining or transformation. In general, each stage of hydrocarbon processing regards the material, it receives for alteration as its feedstock and what it makes of that material as it product. A cracker, for instance, takes naphtha as its feedstock and yields ethylene, its product.
The feedstock business deals in those partially refined petroleum streams intermediates and gas plant products processed by refinery units and basic petrochemical plants. Fiber - A single homogeneous strand of material having a length of at least 5 mm, which can be spun into a yarn or roving, or made into a fabric by interlacing in a variety of methods.
Also a thread-like structure having a length at least times its diameter. Fibers can be made by chopping filaments converting. Staple fibers may be one-half to a few inches in length and usually 1 to 5 denier. Filament - A variety of fiber characterized by extreme length, which permits its use in yarn with little or no twist and usually without the spinning operation required for fibers. Filler - A relatively inert material used as the discontinuous phase of a polymer composite.
Film - An optional term for sheet having a nominal thickness not greater than 0. Flexibility - The degree to which a processing unit can make a desired product from various feed stocks. The term applies particularly to steam crackers. Some such plants can produce ethylene from a range of hydrocarbon streams spanning ethane to vacuum gasoil. Other units have less flexibility. The process requires high temperatures and the presence of a specialized catalyst.
Propylene is a petrochemical by-product of FCC units. The merchandise must be placed aboard the ship by the seller at the designated port of shipment. It is the buyer who chooses the ship and pays for the freight. The risk and expenses transfer between the seller and buyer is done when the merchandise passes the ship's rail. Export formalities are the seller's responsibility. Force Majeure - Legal terminology for excusing either party for failure to comply with the contract for reasons that are out of their immediate control.
Examples include unexpected production outages, acts of God like weather , war, or inability to procure feedstocks. Plastics producers may declare force majeure after an unexpected plant outage if it cannot supply its obligations to its customers.
Rule of Thumb - A force majeure generally has an affect on plastics prices, assuming the market is not severely oversupplied. A force majeure, unlike planned maintenance, is not factored into current prices, meaning players have assumed those supplies would be available and current prices reflect that assumption.
A force majeure may also force both the producer and its customers into the spot market to cover their requirements which can make a temporary bounce up in demand and this can help push up prices.
Formula versus Market Pricing - Market pricing, as the name implies, is a freely negotiated price between buyer and seller with each having other options. Formula pricing is more commonly agreed upon for products with a very limited number of either buyers or sellers, or simply in cases where both parties are willing to agree to fix a component such as costs or margin.
Free radical - A chemical component that contains a free electron which covalently bonds with a free electron on another molecule. Fractionation - The process by which saturated hydrocarbons are removed from natural gas and separated into distinct products, or "fractions," such as propane, butane, and ethane.
Fractions - Part of a hydrocarbon mixture isolated according to the temperature where it evaporates. Distillation units ordinarily divide a combination of liquid hydrocarbons, such as crude oil or the output stream of a cracker, by sorting its molecules into portions with different boiling ranges. These parts, or fractions, also go by the name, cuts. The bottom and top temperatures of a fraction sometimes serve as its designation, as in fraction. Gas Oil - A liquid petroleum distillate having a viscosity intermediate between that of kerosene and lubricating oil.
It derives its name from having originally been used in the manufacture of illuminating gas. It is now an intermediate distillate product used for diesel fuel, heating fuel and sometimes as feedstock for petrochemicals. Gasoline - A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in spark-ignition engines. Gasoline Blending Components - Naphthas e.
Glass transition temperature, Tg - The temperature where the molecules of a polymer can begin to move relative to one another, giving a substance that behaves like a rubber, rather than a brittle glass.
Grade - The designation given a material by a manufacturer such that it is always reproduced to the same specifications established by the manufacturer. Graft copolymer - A polymer with polymer chains which are a different kind of polymer than the backbone chain growing out of it. Granule - Molding compound in the form of spheres or small cylindrical pellets.
Hardness - Resistance of a polymer surface to deformation. HDA - Hydrodealkylation, a process used for making benzene from toluene. High-density polyethylene HDPE - A plastic used in the manufacture of plastic items, such as plastic pipe, grocery bags, water coolers and milk bottles. Homopolymer - A polymer which consists only of one type of monomer unit. Hydrocarbon - An organic chemical compound of hydrogen and carbon in either gaseous, liquid, or solid phase. The molecular structure of hydrocarbon compounds varies from the simplest e.
Hydrocracker - Refinery units which use a catalyst and extraordinary high pressure, in the presence of surplus hydrogen, to shorten molecules. This process can crack a variety of hydrocarbons. It might change atmospheric gasoil to naphtha or reduce naphtha to LPG. In most cases, though, refiners use it to convert vacuum gasoil to high quality middle distillate.
In periods of strong motor gasoline demand, high severity operations can emphasize production of naphtha, called hydrocrackate, instead of diesel and kerosene. Hydrogenation - Chemical process whereby hydrogen is introduced into a compound. Hydrolysis - Chemical decomposition of a substance involving the addition of water.
Hydrophobic - From the Greek words for water hydro and fear phobos. A compound is hydrophobic if it "hates" water and will not dissolve in it. The reverse situation is called hydrophilic. Impact strength - A material's ability to withstand shock loading. Examples of naturally occurring polymers are silk, wool, DNA, cellulose and proteins. In our previous section on network polymers, we mentioned vulcanized rubber and pectin.
Vulcanized rubber is a synthetic man-made polymer, while pectin is an example of a natural polymer. Rubber can be found in nature and harvested as a latex milky liquid from several types of trees. Natural rubber coming from tree latex is essentially a polymer made from isoprene units with a small percentage of impurities in it. Rubber can also be made synthesized by man. Synthetic rubber can be made from the polymerization of a variety of monomers, including isoprene.
Natural rubber does not handle easily it's sticky , nor does it have very good properties or durability it rots. I agree. The major chemical elements making up petroleum are oxygen O , hydrogen H , and carbon C. Petroleum is decomposed under heat into gasoline, kerosene, naphtha, light oil, heavy oil, etc.
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