Who invented rubber? How rubber is made. When did winter tires appear?
The history of the discovery of rubber begins with the discovery of the American continent. For a long time, the indigenous people of Central and South America obtained rubber by collecting the milky sap from rubber trees.
Columbus once noticed that the balls the Indians played with were made of black rubber, and they bounced much better than the leather balls made by the Europeans. Not only balls were made from rubber, but also utensils, they used to seal the bottom of a pie, they created “stockings” that did not get wet (this was a rather painful technology: the legs were covered with a rubber mass, then they had to be held over the fire until a waterproof coating was formed) . Rubber was also used as glue; the Indians used it to decorate their bodies with feathers.
Columbus reported the existence of an extraordinary substance with numerous properties, but Europe did not pay due attention to this, although even the first settlers of the New World actively used rubber. For a long time, rubber was used to create soft toys, and attempts were also made to create a waterproof coating for shoes.
It was only in 1839 that the American inventor Charles Goodyear made a discovery. He stabilized the elastic composition of rubber by mixing raw rubber and sulfur, with further heating. This method was called vulcanization, most likely it was the first polymerization process in industry.
The material that was obtained as a result of the vulcanization process was called rubber. Later, rubber began to be actively used in the engineering industry, creating various seals and hoses. And when electrical engineering was just beginning to develop, it needed durable and elastic material for cables. Today rubber is used everywhere. These rubber mats are in great demand http://www.ru.all.biz/kovriki-rezinovye-bgg1001384. They are used in corridors, vestibules, in front of the entrance to a room, on the porch. These mats prevent dirt and snow from entering your home.
The production of rubber from refined petroleum products and gases dates back to 1951. For a long time, artificially created rubber was superior to real rubber in all respects except one - elasticity. But this problem was also solved.
Thus, the Hevea tree, being a natural gift, random experiments, and long-term painstaking work of scientists have developed one of the most necessary and universally used materials - rubber. Rubber is in demand every day, in various situations, in absolutely any field of human activity.
1817 - German baron Karl von Drais invented a bicycle made entirely of wood. We can say that it had wooden tires installed on it.
1844 - Charles Goodyear discovered the process of vulcanizing rubber, which changed the history of bicycle tires. Before the discovery of the vulcanization process, rubber was unstable because it did not retain its shape: it became too soft in hot weather and brittle in cold weather. Goodyear's invention transformed rubber into a soft material that was ideal for bicycle tires. For several years, bicycle tires have been made of hard rubber. Although they were heavy and did not provide a smooth ride, they were still stronger than the previous ones. Today you can still find several types of hard rubber tires.
1845 - Engineer Robert Thompson from England received a patent for his invention. The Thompson tire consisted of a tube, which was made of pieces of canvas impregnated with rubber and the tire itself was made of leather, attached to the wheel rim with rivets. Thompson called this invention the air wheel. Thompson's ingenious invention was not a commercial success and was soon forgotten.
1870 - In England, an engineer named James Starley produces a bicycle that uses solid molded rubber tires mounted on steel wheels.
1882 - Thomas B. Jeffrey, a bicycle manufacturer and inventor, received a patent for an improved tire. The innovation was that he fused a wire into the rubber along the edges of the tire, which firmly fixed it to the wheel rim. Previously, bicycle tires were attached to the edge of the rim using glue or rivets, which was unsafe because the tires often came off the rim.
1887 - Scottish veterinarian develops the world's first air-filled pneumatic tire for his son's tricycle. The Dunlop tire, for which he was granted a patent in 1888, has a leather hose serving as the inner tube and the outer part of the tire with a rubber tread. His invention made it possible to ride a bicycle comfortably. Such tires were used until the invention of a separate tube.
1893 - August Schroeder and his son George Schroeder invent an improved version of the valve for holding and inflating air in tires. Shredder valves are still widely used in the bicycle tire industry.
1911 - Philip Strauss invented a combination where there was a rubber tube filled with air inside and a rubber tire on the outside.
1933 - German engineer and entrepreneur who emigrated to America Ignaz Schwin developed an expanded tire, which gave rise to off-road use of the bicycle.
1978 - Launch of the first high-quality folding Turbo tires.
Modern bicycle tires have been in use since the 1970s, with many modifications and improvements aimed at reliability and to improve athletic performance. Modern tires are designed with a strong emphasis on aerodynamics, light weight and special materials that provide efficiency and minimal drag when driving. With the advent of modern technology and computer-aided design, the bicycle tire continues to evolve.
Also read on this topic:
Or take, for example, the period from 1951 to 1956, when a group of young cyclists, about 20 people from France, tried to develop a bicycle surprisingly similar to a modern mountain bike. It was equipped with a large number of technical innovations...
It is almost impossible to determine the inventor and the place of invention; the theory about this is based on guesswork and those small scraps of information that have survived to this day. About the same as it is impossible to determine when and where people learned to use the combustion process...
1817 - German baron Karl von Drais invented a bicycle made entirely of wood. We can say that it had wooden tires installed on it...
Having a mobile phone or any means of Internet access, you can see where there is a free bicycle nearby in your area and make a request for its use before leaving home. After this, the customer receives a PIN code...
Speed and maneuverability, small dimensions and low cost of the bicycle played a role in the choice of this type of transport to equip police patrols. A bicycle has the advantages of moving in traffic jams, maneuvering between cars, traveling on sidewalks...
RUBBER AND RUBBER
Rubber is a substance obtained from rubber-bearing plants, growing mainly in the tropics and containing a milky fluid (latex) in the roots, trunk, branches, leaves or fruits or under the bark. Rubber is a product of vulcanization of rubber-based compositions. Latex is not a plant sap, and its role in the life of the plant is not fully understood. Latex contains particles that coagulate into a solid elastic mass called raw or unprocessed rubber.
SOURCES OF NATURAL RUBBER
Raw natural rubber comes in two types:
1) wild rubber, extracted from trees, bushes and vines growing naturally;
2) plantation rubber, extracted from trees and other plants cultivated by humans. During the 19th century. The entire mass of raw rubber for industrial use was wild rubber, extracted by tapping Hevea brasiliensis in the equatorial tropical forests of Latin America, from trees and vines in equatorial Africa, on the Malay Peninsula and the Sunda Islands.
PROPERTIES OF RUBBER
Crude rubber, intended for subsequent industrial use, is a dense amorphous elastic material with a specific gravity of 0.91-0.92 g/cm3 and a refractive index of 1.5191. Its composition varies among different latexes and plantation preparation methods. The results of a typical analysis are presented in the table.
Rubber hydrocarbon is polyisoprene, a hydrocarbon polymer chemical compound having the general formula (C5H8)n. Exactly how rubber hydrocarbons are synthesized in wood is unknown. Unvulcanized rubber becomes soft and sticky in warm weather and brittle in cold weather. When heated above 180° C in the absence of air, rubber decomposes and releases isoprene. Rubber belongs to the class of unsaturated organic compounds that exhibit significant chemical activity when interacting with other reactive substances. Thus, it reacts with hydrochloric acid to form rubber hydrochloride, and also with chlorine by addition and substitution mechanisms to form chlorinated rubber. Atmospheric oxygen acts on rubber slowly, making it hard and brittle; ozone does the same thing faster. Strong oxidizing agents, such as nitric acid, potassium permanganate and hydrogen peroxide, oxidize rubber. It is resistant to alkalis and moderately strong acids. Rubber also reacts with hydrogen, sulfur, sulfuric acid, sulfonic acids, nitrogen oxides and many other reactive compounds, forming derivatives, some of which have industrial applications. Rubber is insoluble in water, alcohol or acetone, but swells and dissolves in benzene, toluene, gasoline, carbon disulfide, turpentine, chloroform, carbon tetrachloride and other halogenated solvents, forming a viscous mass used as an adhesive. Rubber hydrocarbon is present in latex in the form of a suspension of tiny particles, the size of which ranges from 0.1 to 0.5 microns. The largest particles are visible through an ultramicroscope; they are in a state of continuous motion, which can illustrate a phenomenon called Brownian motion. Each rubber particle carries a negative charge. If a current is passed through the latex, then such particles will move to the positive electrode (anode) and be deposited on it. This phenomenon is used in industry to coat metal objects. On the surface of rubber particles there are adsorbed proteins that prevent the latex particles from approaching each other and their coagulation. By replacing the substance adsorbed on the surface of the particle, you can change the sign of its charge, and then rubber particles will be deposited on the cathode. Rubber has two important properties that determine its industrial use. In the vulcanized state, it is elastic and, after stretching, returns to its original shape; in the unvulcanized state it is plastic, i.e. flows under the influence of heat or pressure. One property of rubbers is unique: when stretched, they heat up, and when compressed, they cool. Instead, rubber contracts when heated and expands when cooled, demonstrating a phenomenon called the Joule effect. When stretched by several hundred percent, the rubber molecules are oriented to such an extent that its fibers give an X-ray pattern characteristic of a crystal. The molecules of rubber extracted from Hevea have a cis configuration, while the molecules of balata and gutta percha have a trans configuration. Being a poor conductor of electricity, rubber is also used as an electrical insulator.
RUBBER PROCESSING AND RUBBER PRODUCTION
Plasticization. One of the most important properties of rubber - plasticity - is used in the production of rubber products. To mix rubber with other rubber compound ingredients, it must first be softened, or plasticized, by mechanical or thermal treatment. This process is called rubber plasticization. T. Hancock's discovery in 1820 of the possibility of plasticizing rubber was of great importance for the rubber industry. His plasticizer consisted of a spiked rotor rotating in a spiked hollow cylinder; this device was manually driven. In the modern rubber industry, three types of similar machines are used before introducing other rubber components into the rubber. These are a rubber grinder, a Banbury mixer and a Gordon plasticizer. The use of granulators - machines that cut rubber into small granules or plates of uniform size and shape - facilitates dosing operations and controlling the rubber processing process. The rubber is fed into the granulator upon exiting the plasticizer. The resulting granules are mixed with carbon black and oils in a Banbury mixer to form a masterbatch, which is also granulated. After processing in a Banbury mixer, it is mixed with vulcanizing agents, sulfur and vulcanization accelerators.
Preparation of rubber mixture. A chemical compound of rubber and sulfur alone would have limited practical use. To improve the physical properties of rubber and make it more suitable for use in various applications, it is necessary to modify its properties by adding other substances. All substances mixed with rubber before vulcanization, including sulfur, are called rubber compound ingredients. They cause both chemical and physical changes in the rubber. Their purpose is to modify hardness, strength and toughness and increase resistance to abrasion, oil, oxygen, chemical solvents, heat and cracking. Different compounds are used to make rubber for different applications.
Accelerators and activators. Certain chemicals called accelerators, when used in conjunction with sulfur, reduce curing time and improve the physical properties of rubber. Examples of inorganic accelerators are white lead, litharge (lead monoxide), lime and magnesia (magnesium oxide). Organic accelerators are much more active and are an important part of almost any rubber compound. They are added to the mixture in a relatively small proportion: usually from 0.5 to 1.0 parts per 100 parts of rubber is sufficient. Most accelerators are fully effective in the presence of activators such as zinc oxide, and some require an organic acid such as stearic acid. Therefore, modern rubber compound formulations usually include zinc oxide and stearic acid.
Softeners and plasticizers. Softeners and plasticizers are usually used to reduce the time of preparation of the rubber mixture and lower the temperature of the process. They also help disperse the ingredients of the mixture, causing the rubber to swell or dissolve. Typical softeners are paraffin and vegetable oils, waxes, oleic and stearic acids, pine tar, coal tar and rosin.
Strengthening fillers. Certain substances strengthen rubber, giving it strength and resistance to wear. They are called strengthening fillers. Carbon black (gas) in finely ground form is the most common strengthening filler; it is relatively cheap and is one of the most effective substances of its kind. The tread rubber of a car tire contains approximately 45 parts carbon black to 100 parts rubber. Other commonly used strengthening fillers are zinc oxide, magnesium carbonate, silica, calcium carbonate and some clays, but all are less effective than carbon black.
Fillers. In the early days of the rubber industry, even before the advent of the automobile, certain substances were added to rubber to reduce the cost of the products obtained from it. Hardening was not yet of great importance, and such substances simply served to increase the volume and mass of rubber. They are called fillers or inert rubber ingredients. Common fillers are barite, chalk, some clays and diatomaceous earth.
Antioxidants. The use of antioxidants to maintain the desired properties of rubber products during their aging and use began after World War II. Like vulcanization accelerators, antioxidants are complex organic compounds that, at a concentration of 1-2 parts per 100 parts of rubber, prevent the growth of rubber hardness and brittleness. Exposure to air, ozone, heat and light is the main cause of rubber aging. Some antioxidants also protect rubber from damage due to bending and heat.
Pigments. Strengthening and inert fillers and other rubber compound ingredients are often called pigments, although real pigments are also used to impart color to rubber products. Zinc and titanium oxides, zinc sulfide and lithopone are used as white pigments. Crown yellow, iron oxide pigment, antimony sulfide, ultramarine and lamp black are used to give various color shades to products.
Calendering. Once the raw rubber is plasticized and mixed with rubber compound ingredients, it is further processed before vulcanization to shape it into the final product. The type of treatment depends on the application of the rubber product. Calendering and extrusion are widely used at this stage of the process. Calenders are machines designed for rolling rubber mixture into sheets or coating fabrics with it. A standard calender usually consists of three horizontal rollers stacked one above the other, although four-shaft and five-shaft calenders are used for some applications. Hollow calender rolls have a length of up to 2.5 m and a diameter of up to 0.8 m. Steam and cold water are supplied to the rolls to control the temperature, the selection and maintenance of which is crucial to obtain a quality product with a constant thickness and a smooth surface. Adjacent shafts rotate in opposite directions, with the rotation speed of each shaft and the distance between the shafts precisely controlled. The calender is used to coat fabrics, coat fabrics, and roll out the rubber mixture into sheets.
Extrusion. The extruder is used to form pipes, hoses, tire treads, pneumatic tire tubes, automotive gaskets and other products. It consists of a cylindrical steel body equipped with a heating or cooling jacket. A screw that fits tightly to the body feeds the unvulcanized rubber mixture, preheated on the rollers, through the body to the head, into which a replaceable molding tool is inserted, which determines the shape of the resulting product. The product emerging from the head is usually cooled by a stream of water. Pneumatic tire tubes come out of the extruder as a continuous tube, which is then cut to the required length. Many products, such as gaskets and small tubing, come out of the extruder in their final shape and are then cured. Other products, such as tire treads, come out of the extruder as straight blanks, which are subsequently applied to and vulcanized to the tire body, changing their original shape.
Curing. Next, it is necessary to vulcanize the workpiece to obtain a finished product suitable for use. Vulcanization is carried out in several ways. Many products are given their final shape only at the vulcanization stage, when the rubber mixture enclosed in metal molds is exposed to temperature and pressure. Car tires, after being assembled on a drum, are molded to the desired size and then vulcanized in grooved steel molds. The molds are placed one on top of the other in a vertical vulcanizing autoclave, and steam is released into a closed heater. An air bag of the same shape as the tire tube is inserted into the unvulcanized tire blank. Air, steam, hot water are released into it through flexible copper tubes, individually or in combination with each other; These pressure transfer fluids push the tire carcass apart, forcing the rubber to flow into the shaped recesses of the mold. In modern practice, technologists are striving to increase the number of tires vulcanized in separate vulcanizers called molds. These casting molds have hollow walls that allow internal circulation of steam, hot water, and air to transfer heat to the workpiece. At the specified time, the molds open automatically. Automated vulcanizing presses have been developed that insert a cooking chamber into a tire blank, vulcanize the tire, and remove the cooking chamber from the finished tire. The cooking chamber is an integral part of the vulcanization press. Tire tubes are vulcanized in similar molds that have a smooth surface. The average vulcanization time for one chamber is about 7 minutes at 155° C. At lower temperatures, the vulcanization time increases. Many smaller products are cured in metal molds that are placed between parallel platens in a hydraulic press. The press plates are hollow inside to provide steam access for heating without direct contact with the product. The product receives heat only through a metal mold. Many products are vulcanized by heating in air or carbon dioxide. Rubberized fabric, clothing, raincoats and rubber shoes are vulcanized in this way. The process is usually carried out in large horizontal vulcanizers with a steam jacket. Dry heat vulcanized rubber compounds usually contain less sulfur to prevent some of the sulfur from escaping onto the surface of the product. To reduce the vulcanization time, which is usually longer than with open steam or press vulcanization, accelerator substances are used. Some rubber products are vulcanized by immersion in hot water under pressure. The rubber sheet is wound between layers of muslin on a drum and vulcanized in hot water under pressure. Rubber bulbs, hoses, and wire insulation are vulcanized in open steam. Vulcanizers are usually horizontal cylinders with tightly fitting lids. Fire hoses are vulcanized with steam from the inside and thus act as their own vulcanizers. The rubber hose is pulled inside the braided cotton hose, connecting flanges are attached to them, and steam is injected under pressure into the workpiece for a specified time. Vulcanization without heat can be carried out using sulfur chloride S2Cl2 by either immersion in a solution or exposure to vapor. Only thin sheets or items such as aprons, bathing caps, finger guards or surgical gloves are vulcanized in this way because the reaction is rapid and the solution does not penetrate deeply into the workpiece. Additional treatment with ammonia is necessary to remove the acid formed during the vulcanization process.
HARD RUBBER
Hard rubber products differ from soft rubber products mainly in the amount of sulfur used in vulcanization. When the amount of sulfur in a rubber compound exceeds 5%, vulcanization results in hard rubber. The rubber compound can contain up to 47 parts of sulfur per 100 parts of rubber; this produces a hard and tough product, called ebonite, because it is similar to ebony (black) wood. Hard rubber products have good dielectric properties and are used in the electrical industry as insulators, such as switchboards, plugs, sockets, telephones and batteries. Pipes, valves and fittings made using hard rubber are used in areas of the chemical industry where corrosion resistance is required. The manufacture of children's toys is another source of hard rubber consumption.
SYNTHETIC RUBBER
The synthesis of rubber that occurs in wood has never been done in a laboratory. Synthetic rubbers are elastic materials; they are similar to the natural product in chemical and physical properties, but differ from it in structure. Synthesis of an analogue of natural rubber (1,4-cis-polyisoprene and 1,4-cis-polybutadiene). Natural rubber, obtained from Hevea brasiliensis, has a structure consisting of 97.8% 1,4-cis-polyisoprene:
The synthesis of 1,4-cis-polyisoprene has been carried out in several different ways using stereostructure-controlling catalysts, and this has enabled the production of various synthetic elastomers. The Ziegler catalyst consists of triethylaluminum and titanium tetrachloride; it causes isoprene molecules to combine (polymerize) to form giant molecules of 1,4-cis-polyisoprene (polymer). Likewise, lithium metal or alkyl and alkylene lithium compounds, such as butyllithium, serve as catalysts for the polymerization of isoprene to 1,4-cis-polyisoprene. Polymerization reactions with these catalysts are carried out in solution using petroleum hydrocarbons as solvents. Synthetic 1,4-cis-polyisoprene has the properties of natural rubber and can be used as its substitute in the production of rubber products.
see also PLASTICS. Polybutadiene, consisting of 90-95% 1,4-cis isomer, has also been synthesized via stereostructure-regulating Ziegler catalysts such as triethylaluminum and titanium tetraiodide. Other stereostructure-controlling catalysts, such as cobalt chloride and aluminum alkyl, also produce polybutadiene with a high (95%) content of the 1,4-cis isomer. Butyllithium is also capable of polymerizing butadiene, but produces polybutadiene with a lower (35-40%) content of the 1,4-cis isomer. 1,4-cis-polybutadiene has extremely high elasticity and can be used as a filler in natural rubber. Thiokol (polysulfide rubber). In 1920, while trying to make a new antifreeze from ethylene chloride and sodium polysulfide, J. Patrick instead discovered a new rubber-like substance, which he called thiokol. Thiokol is highly resistant to gasoline and aromatic solvents. It has good aging characteristics, high tear resistance and low gas permeability. Although not a true synthetic rubber, it is nevertheless used for the manufacture of special-purpose rubbers.
Neoprene (polychloroprene). In 1931, DuPont announced the creation of a rubber-like polymer, or elastomer, called neoprene. Neoprene is made from acetylene, which in turn is made from coal, limestone and water. Acetylene is first polymerized to vinyl acetylene, from which chloroprene is produced by adding hydrochloric acid. Next, chloroprene is polymerized to neoprene. In addition to being oil-resistant, neoprene has high heat and chemical resistance and is used in hoses, pipes, gloves, and machine parts such as gears, gaskets, and drive belts. Buna S (SBR, styrene butadiene rubber). Buna S synthetic rubber, referred to as SBR, is produced in large jacketed reactors, or autoclaves, that are charged with butadiene, styrene, soap, water, a catalyst (potassium persulfate) and a chain growth regulator (mercaptan). Soap and water serve to emulsify the butadiene and styrene and bring them into close contact with the catalyst and chain growth regulator. The contents of the reactor are heated to approximately 50 ° C and stirred for 12-14 hours; During this time, as a result of the polymerization process in the reactor, rubber is formed. The resulting latex contains rubber in small particle form and has a milky appearance, much like natural latex extracted from wood. The latex from the reactors is treated with a polymerization interrupter to stop the reaction and an antioxidant to preserve the rubber. It is then purified from excess butadiene and styrene. To separate (by coagulation) rubber from latex, it is treated with a solution of sodium chloride (table salt) in acid or a solution of aluminum sulfate, which separates the rubber in the form of fine crumbs. Next, the crumbs are washed, dried in an oven and pressed into bales. Of all the elastomers, SBR is the most widely used. Most of it goes to the production of car tires. This elastomer has properties similar to natural rubber. It is not oil resistant and exhibits low chemical resistance in most cases, but has high impact and abrasion resistance.
Latexes for emulsion paints. Styrene-butadiene latexes are widely used in emulsion paints, in which the latex forms a mixture with the pigments of conventional paints. In this application, the styrene content of the latex must exceed 60%.
Low temperature oil-extended rubber. Low temperature rubber is a special type of SBR rubber. It is produced at 5°C and provides better tire wear resistance than standard SBR produced at 50°C. Tire wear resistance is further enhanced if the low temperature rubber is given high impact strength. To do this, certain petroleum oils called petroleum softeners are added to the base latex. The amount of oil added depends on the required impact strength value: the higher it is, the more oil is added. The added oil acts as a hard rubber softener. Other properties of oil-extended low-temperature rubber are the same as those of ordinary low-temperature rubber.
Buna N (NBR, butadiene acrylonitrile rubber). Along with Buna S, an oil-resistant type of synthetic rubber called perbunan, or Buna N, was also developed in Germany. The main component of this nitrile rubber is also butadiene, which copolymerizes with acrylonitrile by essentially the same mechanism as SBR. NBR grades differ in the content of acrylonitrile, the amount of which in the polymer varies from 15 to 40% depending on the purpose of the rubber. Nitrile rubbers are oil resistant to a degree corresponding to their acrylonitrile content. NBR was used in military equipment where oil resistance was required, such as hoses, self-sealing fuel cells, and vehicle structures.
Butyl rubber. Butyl rubber, another synthetic rubber, was discovered in 1940. It is remarkable for its low gas permeability; A tire tube made of this material retains air 10 times longer than a tube made of natural rubber. Butyl rubber is made by polymerizing isobutylene obtained from petroleum with a small addition of isoprene at a temperature of -100 ° C. This polymerization is not an emulsion process, but is carried out in an organic solvent, such as methyl chloride. The properties of butyl rubber can be greatly improved by heat treating a masterbatch of butyl rubber and carbon black at temperatures ranging from 150 to 230° C. Butyl rubber has recently found new use as a tire tread material due to its good driving characteristics, lack of noise and excellent traction. Butyl rubber is incompatible with natural rubber and SBR and therefore cannot be mixed with them. However, once chlorinated to chlorobutyl rubber, it becomes compatible with natural rubber and SBR. Chlorobutyl rubber retains low gas permeability. This property is exploited in the manufacture of CBR/natural rubber blended products, or SBR, which are used to produce the inner liner of tubeless tires.
Ethylene propylene rubber. Ethylene-propylene copolymers can be produced in a wide range of compositions and molecular weights. Elastomers containing 60-70% ethylene are vulcanized with peroxides and produce a vulcanizate with good properties. Ethylene propylene rubber has excellent weather and ozone resistance, high heat, oil and wear resistance, but also high breathability. This rubber is made from cheap raw materials and has numerous industrial applications. The most widely used type of EPDM is EPDM (diene comonomer). It is mainly used for making wire and cable sheaths, single-ply roofing and as an additive for lubricating oils. Its low density and excellent ozone and weather resistance lead to its use as a roofing material.
Vistanex. Vistanex, or polyisobutylene, is an isobutylene polymer, also produced at low temperatures. It is similar in properties to rubber, but unlike rubber it is a saturated hydrocarbon and, therefore, cannot be vulcanized. Polyisobutylene is ozone resistant.
Korosil. Korosil, a rubber-like material, is a plasticized polyvinyl chloride made from vinyl chloride, which in turn is obtained from acetylene and hydrochloric acid. Korosil is remarkably resistant to oxidizing agents, including ozone, nitric and chromic acids, and is therefore used for the internal lining of tanks to protect them from corrosion. It is impervious to water, oils and gases and is therefore used as a coating for fabrics and paper. Calendered material is used in the production of raincoats, shower curtains and wallpaper. Low water absorption, high electrical strength, non-flammability and high aging resistance make plasticized polyvinyl chloride suitable for the manufacture of wire and cable insulation.
Polyurethane. A class of elastomers known as polyurethanes are used in the production of foams, adhesives, coatings and molded products. The production of polyurethanes includes several stages. First, a polyester is prepared by reacting a dicarboxylic acid, such as adipic acid, with a polyhydric alcohol, in particular ethylene glycol or diethylene glycol. The polyester is treated with a diisocyanate, for example toluylene-2,4-diisocyanate or methylene diphenylene diisocyanate. The product of this reaction is treated with water and a suitable catalyst, in particular n-ethylmorpholine, to obtain an elastic or flexible polyurethane foam. By adding diisocyanate, molded products are obtained, including tires. By varying the ratio of glycol to dicarboxylic acid during the polyester production process, polyurethanes can be made that are used as adhesives or processed into rigid or flexible foams or molded products. Polyurethane foams are fire-resistant, have high tensile strength, and very high tear and abrasion resistance. They exhibit exceptionally high load-bearing capacity and good aging resistance. Vulcanized polyurethane rubbers have high tensile strength, abrasion, tear and aging resistance. A process was developed to produce polyurethane rubber based on polyether. This rubber behaves well at low temperatures and is resistant to aging.
Organosilicon rubber. Organosilicon rubbers have no equal in their suitability for use in a wide temperature range (from -73 to 315° C). For vulcanized silicone rubbers, a tensile strength of about 14 MPa has been achieved. Their aging resistance and dielectric characteristics are also very high.
Hypalon (chlorosulfoethylene rubber). This chlorosulfonated polyethylene elastomer is produced by treating polyethylene with chlorine and sulfur dioxide. Vulcanized Hypalon is extremely ozone and weather resistant and has good thermal and chemical resistance.
Fluorinated elastomers. Elastomer kel-F is a copolymer of chlorotrifluoroethylene and vinylidene fluoride. This rubber has good heat and oil resistance. It is resistant to corrosive substances, non-flammable and suitable for use in the range from -26 to 200 ° C. Viton A and fluorel are copolymers of hexafluoropropylene and vinylidene fluoride. These elastomers have excellent resistance to heat, oxygen, ozone, weathering and sunlight. They have satisfactory low temperature performance and are suitable for use down to -21°C. Fluorine-containing elastomers are used in applications where resistance to heat and oils is required.
Specialized elastomers. Specialized elastomers with a variety of physical properties are produced. Many of them are very expensive. The most important of these are acrylate rubbers, chlorosulfonated polyethylene, ether copolymers, epichlorohydrin polymers, fluorinated polymers and thermoplastic block copolymers. They are used to make seals, gaskets, hoses, wire and cable sheaths and adhesives.
see also
An article about the creation of tires will help you find out how tires were invented and changed, and what made them so stable, reliable, durable and wear-resistant.
Today it is difficult to imagine that once upon a time there were no tires on the wheels of a car. This was in the era of the first cars and wooden wheels. True, even with light use they quickly deteriorated and required replacement. The invention of a wheel reinforced with a steel rim (the prototype of a modern disk) solved this problem, but this technology did not give the desired results.
The story of the creation of car tires
Robert William Thompson was the first to use tires made of elastic material to increase the comfort and safety of a car in 1846, developed a tire design and patented his invention. The tire invented by Thompson was also called the “air wheel.” It was a chamber made of thick canvas, soaked in a solution of rubber or gutta-percha, and lined on the outside with pieces of leather.
Thompson's initiatives were picked up by others who invented them. Numerous experiments by enthusiasts were crowned with success: a rubber pneumatic tire was invented, with a tire separated from the tube. The advent of the pneumatic wheel made driving smoother. The tires themselves have become stronger and more durable (these parameters were absent in the first variations of the invention).
Discovery of vulcanization
An article about the invention of tires is impossible without mentioning Charles Goodyear.
The vulcanization process made it possible to organize the production of a truly durable, yet elastic tire. American inventor Charles Goodyear did not even suspect in 1839 that the technology he created for producing rubber by combining rubber and sulfur would become an integral part of the production of automobile tires.
In the 1830s, Goodyear was involved in the production of rubberized shoes and cloth. At his enterprise he produced rubber toys, clothes, shoes, and umbrellas. However, the properties of this material did not allow the goods to be of high quality: rubber melted at high temperatures, was fragile and had other disadvantages.
Goodyear took this problem seriously. Through experimentation, he learned that heating rubber mixed with sulfur gave the material the necessary strength, not only on the surface, but throughout its entire thickness. It is safe to say that 1839 is the time of the invention of rubber for cars.
Goodyear Company. Foundation and first years of work
The Goodyear Tire & Rubber Company was registered in 1898 in the USA. The history of Goodyear tires began that day. The founder, Frank Sieberling, named his company after the same inventor of vulcanization technology.
From the very foundation of the company, its products have become in demand and purchased. Just 4 years later, in 1901, the company began to create tires for the car of the famous Henry Ford. The Model T, famous in those years, was equipped with Goodyear tires.
In 1907, the chairman of the board of the brand received a patent for the removable tire he invented. This Goodyear technology is used everywhere today.
Experiments, constant improvement of product characteristics and the introduction of new technologies allowed the concern to become the world's largest manufacturer of automobile tires and other rubber products by 1926.
Expansion of activities
In the period from 1927 to the present day, the company has been actively developing, developing new production capabilities, improving designs, and designing tires not only for cars, but also for aircraft. In 1971, the manufacturer released tires for the Apollo 14 lunar rover. The tread imprints of these tires remained on the moon for centuries.
During these years, scientific and technical centers and representative offices were opened in many countries around the world, and agreements were concluded with well-known brands. All this allows Goodyear to be one step ahead of its competitors - the company is the first to introduce innovative solutions, introducing new products with improved characteristics to the market.
It is also worth mentioning the impeccable reputation of the brand. Goodyear has repeatedly taken top positions in ratings of the most responsible and reliable companies.
About Goodyear Manufacturing
Based on the history of tire creation, experience and traditions, today the company maintains one of the leading positions among car tire manufacturers. The brand's factories carry out a full cycle of work to create a high-quality tire: from designing a tire and creating a rubber compound to releasing and testing a new product.
Goodyear automobile tires are created on the most modern production lines. Adjusting production processes, the composition of the rubber mixture, improving the tread pattern and adding functional inserts make it possible to produce new models designed for different categories of motorists (residents of northern regions, off-road, trucks, etc.).
Rubber and silica are the main components of a tire.
A pneumatic car tire is a high-tech design that can hold air under pressure. Thanks to the invention of Charles Goodyear, today's car tires are a mixture of natural and artificial rubber, carbon black, sulfur, silicon and synthetic compounds. All these components pass through a mixer during production, resulting in a sheet of raw rubber.
Silica is another material used in modern production. This acid, which improves the elasticity and grip characteristics of rubber, was discovered back in the 50s of the last century. The process of developing technology for adding silica to the mixture in tire production started relatively recently. This is explained by the high cost of the material and the need to use special equipment to mix it with rubber.
Tire design
Pneumatic tires must have several elements:
- frame - the basis of the product, which consists of several layers of rubberized cord,
- sidewall - an external rubber element designed to protect the structure from external damage in the side part,
- bead - rigid attachment to the wheel on the tire,
- breaker - protects the frame from impacts and gives rigidity to the product,
- tread - grooves and grooves on the rubberized surface of the tire, ensuring no slipping and safe movement under adverse external conditions: on mud, dirt roads, wet, snowy or icy roads.
Car tires from Goodyear are constantly being improved, and structural elements acquire new properties.
Nowadays, it is no longer possible to find a person who does not know what tires on cars are intended for. But not everyone knows that tires became like this relatively recently. To trace the history of car tires, it is necessary to go back almost a century and a half in history.
The first rubber tires appeared in the mid-19th century, almost immediately after Charles Goodyear invented the process of producing rubber from rubber. Initially, such tires were wooden wheels, on which a rim made of a solid rubber layer was put on. Molded rubber tires were a breakthrough in providing a smooth ride, allowing the ride to be slightly cushioned while absorbing the shock of bumps in the road. However, although the use of molded rubber tires reduced shaking and vibration, the ride on a vehicle with such wheels was still far from comfortable.
It is believed that the idea of using a layer of air to soften impacts and reduce rolling friction came to the mind of the Scottish engineer Robert Thomson, who received a patent on December 10, 1845 for the invention of “an improved wheel for carts and other moving objects.”
Thomson's "improved wheel" consisted of a wooden rim covered with a metal hoop, onto which an outer leather covering was screwed with bolts. On the outside, the pieces of leather were fastened with rivets. Inside the resulting leather tube was a prototype of a modern camera, only Thomson’s was made of canvas impregnated with a rubber mixture.
Thomson even conducted tests that showed that the use of an “air wheel” can significantly reduce the force required to move the crew. Thomson intended to use similar wheels on carriages, especially noting that the carriage could now move especially smoothly and that, thanks to the use of air tires, it looked as if it was floating above the ground. Robert Thomson published his test results on March 27, 1849 in Mechanics Magazine, attaching detailed drawings and a description of his invention.
However, no one was interested in this invention, and the production of “air wheels” was never started.
The pneumatic tire was reinvented in 1888 by John Boyd Dunlop in Ireland. Dunlop's first pneumatic wheel consisted of a piece of garden hose inflated with air, placed on the rim of the wheel of his son's children's bicycle. The hose was attached to the rim using a wound rubberized canvas tape. To prevent the tape from quickly abrading on the road surface, Dunlop attached a piece of thick rubber tape over the wound canvas tape.
In 1889, a bicycle race was held, in which the victory was won by a rider who used an unusual tire on his bicycle - with a pneumatic tube.
Realizing the promise of his invention, John Dunlop opened a workshop in 1889 for the production of pneumatic bicycle tires - Booth's Pneumatic Tire and Bicycle Agency. Now this company has grown from a small workshop into the international corporation Dunlop.
However, in this form, the pneumatic tire could not be used on cars. In addition, the tire was non-removable, which caused great inconvenience during operation. A very short time later, in 1890, the problem of adapting the tire for installation on cars was solved. Engineer Kingston Welch proposed a new design for the wheel: the tires were made removable, separate from the tube. Metal wire was inserted into the edges of the tire for strength. Thanks to the recess, the camera was better fixed on the rim. To prevent the tire from sliding off the rim, its edges protruded and held the sides of the tire.
In the same year, methods were developed for relatively convenient installation and dismantling of the tire. It was already a matter of time before the use of pneumatic tires on cars began. All that remained was to adapt the design for use on cars with their high (for that time) speeds and heavy loads on the wheels.
The first to produce pneumatic automobile tires were two French brothers, Andre and Edouard Michelin, introducing them in 1895 before the Paris-Bordeaux race. The brothers already had experience making bicycle tires. They made car tires specifically for this race. Nowadays, almost everyone knows the brothers' surname - the Michelin company has grown into a corporation of international scale.
Thanks to the use of pneumatic tires, cars have increased smoothness and maneuverability, and driving on uneven roads is no longer so unpleasant. However, the general distribution of such tires was hampered by their capriciousness in operation, as well as difficulties during installation and dismantling. Therefore, solid rubber and pneumatic tires were produced in parallel.
Further research by engineers to improve pneumatic tires was aimed at eliminating the above shortcomings. Soon, special strips made of various reinforcing materials - cords - were introduced into tires, which increased the service life and unpretentiousness of the tire. The appearance of special mounting machines has significantly speeded up the installation/dismantling of wheels. Among other things, the wheels themselves are removable. Now they were attached to the hubs with several bolts.
Soon the strength of pneumatic tires became sufficient for use on trucks. The number of tires produced has already numbered in the millions.
To improve handling, various tread patterns were developed and research was carried out with different rubber compounds. To reduce dependence on countries that supply natural rubber used to make rubber, synthetic rubber was developed. This made it possible to reduce the cost of tires, as well as stabilize the chemical composition of the rubber, which made it possible to achieve constant chemical and physical characteristics for each tire in the series.
Chemical companies took an active part in improving the quality of tires, not only by selecting new additives for rubber, but also by searching for the best material for the cord. Initially, the cord was made of textiles, but it had low strength, which is why there were frequent cases of tire breaks. Company engineers began experimenting with synthetic materials - the latest viscose and nylon. The use of these materials has significantly increased the strength characteristics of tires. Now cases of tire explosions have become a very rare occurrence.
In the mid-20th century, the Michelin company developed a completely new type of tire: the cords were made of metal and were arranged radially - from bead to bead. Tires with this type of cord are called radial. The use of a radial cord made it possible to increase the strength and service life of the tire several times with the same weight. Or, while maintaining the same strength and speed characteristics, have a much smaller mass.
For all its advantages, a traditional tire with a tube has one significant drawback - when punctured, it deflates almost instantly and movement becomes impossible. To get rid of this drawback, it was necessary to find a way to do without a camera. And therefore tubeless tires were developed, which, even in the event of a puncture, made it possible to travel a certain distance without a significant loss of their strength qualities. However, tubeless tires are more demanding on the quality of manufacture of both the tire itself and the rim. All this is due to the fact that in such wheels the tire must fit as tightly as possible in the disc machine to ensure the necessary level of tightness to retain the air inside.
It may seem surprising to modern car owners, but until the 60s of the 20th century, the tire profile was almost a circle. Further, the height of the tire decreased all the time, sometimes reaching 50 percent of the profile width. Low profile tires have better traction due to their larger contact surface. In addition, by reducing the profile height, directional stability has improved, since such a tire deforms less under lateral loads. A low-profile tire has many advantages, including a non-standard appearance, which gives a car with such wheels a certain sporty aggression. But we must remember that in this case we have to sacrifice maximum carrying capacity. Although this is far from the most important criterion for sports cars. When tuning, car owners often install “sports” low-profile tires even on cars that do not have a “sporty” appearance. But here it’s a matter of taste.
Since the appearance of the first “air wheel” and until today, research has not stopped that would improve the consumer qualities of pneumatic tires. If earlier research mainly went in the direction of increasing the strength of tires and improving grip on the road surface, now this has been supplemented by the desire to create a tire that causes minimal harm to the environment. This includes not only environmentally friendly manufacturing (tire production is historically very dirty from an environmental point of view), but also causing minimal harm during operation (flaking pieces of rubber and escaping gases are important pollutants of the ecosystem). In addition, do not forget that after discontinuation of use, tires must be disposed of somehow. This process is also far from environmentally friendly.
Previously, people did not think about the damage caused by humanity to the environment. But now, fortunately, everything is changing for the better. Research is being conducted that would not only minimize the harm from classic rubber tires, but also aimed at finding a completely different, environmentally friendly material for making footwear for cars. In addition, a way is being sought to somehow move away from the need to use the air chamber as a shock-absorbing agent. For example, there are already proposals to produce tires that, instead of an air “cushion,” would have a layer in the form of a sponge or in the form of large cells.