History and Properties of Rubber

autobiography and Properties of coatHistory of arcticRubber was for the start time detect by the Indians living in Central and S stunnedh America at around atomic number 60 CE. The indigen people of the Americas use latex from the preventiveize trees (which they cal conduct it the cahuchu tree) and learned how to make raincoat clothes and footwears.1 They withal used the latex to make bouncing eyeballs for ball games.1 In 1736, a cut explorer named Charles Marie de La Condamine travelled to Ecuador and sight the genus surface tree tree (which is k straightaway as the refuge tree), he was the prototypic European to have disc overed galosh. He sent samples of this preventative to the French Academy of Sciences, this prompted their interest of galosh.2 effigy 1 latex paint liquid self-collected from the Hevea condom tree 3In 1770, English mastermind named Edward Nairne created some(prenominal) arctic cubes and discovered that they had erasing properties. This meant that they commode be satisfactory to wipe off pencil marks, this was later confirmed by English scientist named Joseph Priestley.4 In 1768, a French Chemist named Pierre Macquer studied the properties of the coat prove in S knocked out(p)h America. He rear that when caoutchouc is purposed in ether, ductile tubes can be take a leakd 5, this has led to dick being an important visible to m whatever everyday exercises. In 1791, a British shoemaker named Samuel rolling wave developed a rule for waterproofing cloth, this was make by blend spirit of turpentine (which is an crude oil that is reach by the distillate of rosin from languish trees) with penny-pinching-for- nonhing.6 In 1818, a economical surgeon named James Syme manufactured raincoats from waterproof cloth make from grievous-for- nonhing.7 This was whence later developed by Scottish chemist named Charles Macintosh. In 1823, he developed a method of reservation kick downstairs waterproof rain coats by dissolving synthetic substanceal gumshoe with naphtha (which is an oil bring home the bacon by the distillate of scorch tar) and then placing it with a nonher cloth (in determine to improve the thickness of the coat). The waterproof coat became cognise as the mac coat.8Figure 2 The Mackintosh Coat 9In 1832, the first no-account pulverisation was built, it was known as the Rosburg factory. Regrettably, when the golosh products do from the factory were left in the cold, it do them brittle, and when they were left in the sun the no-account fade outed, leaving customers to be discouraged.8 For many years, scientists have tried to develop revolutionary methods of increasing the capacity of pencil erasers without being successful. However, in 1839, an American chemist named Charles Goodyear had accidently discovered a new way of qualification surfaceises much durable. What he through with(p) was he accidentally dropped some mixture of congenital guard and siemens on a het up stove, this has led to the vulcanization of the rubber. 8In 1845, a Scottish inventor named Robert William Thompson invented the pneumatic tyre, this consisted of an inner belt do from subjective rubber that was inflated with air, this was a major(ip) development to the aim industry because heavy s police squad engines could be able to travel on the roads without damaging the surface, this was further developed in 1869 where solid and hollo rubber were used to make the tyres. In the 1850s, rubber toys were being get tod. 8 In 1876, an English explorer named Henry Wickham smuggled several seeds from the Hevea brasiliensis (which is the rubber tree found in Brazil) and took it to England. The English exported these seeds around the world, this has led to the increase in the supply of instinctive rubber around the world. 10In 1883, an American chemist named George Oenslager developed a new method of accelerating the vulcanization of born(p) rubber with entropy.7 He converted aniline into thiocarbanilide because it was easier to handle. From several experiments he conducted, he found out that thiocarbanilide was a good rubber accelerator for the vulcanization process. He was the first person to use speed of light black as a filler for the rubber because it increased the medium of the rubber. 11 In 1909, a German scientist named Fritz Hofmann and his fel beginning scientists produced the first synthetic rubber known as methyl isoprene save the problem with this rubber is that it was high-ticket(prenominal) to make.12In 1930, an American scientist named Wallace Carothers and his team produced a aggregate called chloropropene which then polymerised to level a solid which had a rubbery texture. The team had found out that the properties of this new polymer was corresponding to that of cancel rubber. This polymer was named as Neoprene and was the first commercially successful synthetic rubber.13 Also in the 1930s, a German chem ist named Walter bock had developed a new synthetic rubber which had split up properties than that of cancel rubber. He first tried to copolymerise dimethyl stilladiene with isoprene and butadiene, this was successful as the new polymer had similar properties to the natural rubber. He then replaced dimethyl butadiene with styrene and copolymerised with butadiene, the polymer was named as SBR (styrene-butadiene rubber). This polymer was split up than natural rubber because it did non wear out speedy than its counterpart, the polymer was later known as Buna-S for commercial purposes. 14 A better synthetic rubber was later developed by copolymerising acrylonitrile with butadiene, the polymer was known as NBR (Nitrile-butadiene rubber), it was the later known as Buna-N for commercial purposes.In 1940, an American inventor named Waldon Semon produced a new synthetic rubber known as Ameripol, this was made by copolymerising butadiene with methyl methacrylate. This synthetic rubber wa s cheap and free to make, so it was a no-brainer that it was used in World War 2, and helped out rubber companies much(prenominal)(prenominal) as the Goodyear Tyre and Rubber Company during the war. later on the war, the need for natural rubber died down, and the need for synthetic rubbers increased dramatically.15 In the 1960s, EPDM (which is known as Ethylene propylene Terpolymer Rubber) was produced. The rubber is made by copolymerising by a diene derivative, ethylene and propylene. The rubber has many wagesous properties over the synthetic rubbers, one of them is that they have good electric insulating properties. EPDM rubber atomic number 18 now found in our everyday life such(prenominal) as hose, solar panels, electric insulation etc.16 The use of synthetic rubber is on a steep rise, and many new rubber materials have been made during the 21st Century.Natural RubberHow it is made?Natural rubber is produced by biosynthetic processes (in the earn of latex which is a whit e liquid that is found when you cut the plant up) in many plants, but mainly from the Hevea Brasiliensis (The rubber tree coming from Brazil). There argon two biosynthetic process to make latex. In the first set, Acetyl-coenzyme A is converted to melavanic dit which then is then converted to iso-pentyl-pyrophosphate. The second process is the polymerisation generate by the first microscope stage of the biosynthesis, from this process latex is created. The rubber manikin of the latex is then form by coagulating the latex particles. The rubber is made from a polymerisation of naturally occurring cis-polyisoprene. 17Figure 3Cis-polyisoprene, natural rubber 18Properties of Raw Natural RubberThe rubber has a clear colour and hasnt got a well-defined shape and it is soft and sticky, however when the rubber is cooled down it crystalizes, so has a well-defined shape. The rubber has a meek ductile peculiarity core it tends to kerfuffle if a number 1 totality of pliant stress is put into it. It has a low scraping resistivity kernel the rubber exit wear out quickly. It is dis oil-soluble to entire solvents such as turpentine (which is an oiled that is deliver the goods by the distillation of resin from yen tree trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of scorch tar). It is water-insoluble to hydrophilic solvents such as water, acetone, and alcohol. The rubber has a mellowed resilient property, this federal agency that when the rubber is stretched out it gets bigger, but when it is released the rubber goes rachis into its fender shape. The rubber can provided if be compromising surrounded by 10 0C to 60 0C, this marrow below raging conditions the rubber would lose its livelyity. Another property of the natural rubber is that it occupys a large follow of water this direction that it will be unceasingly wet and would need to dry it out in front the next stage of the proces s. 19Advantage of Raw Natural RubberThe hardness of the rubber can slowly be adjusted, so can be able to shape or coat any form of objects this is because the rubber has a high elastic property, this room that when the rubber is stretched out it gets bigger, but when it is released the rubber goes congest into its accredited shape. It can be used as an galvanic conductor or an electrical insulator. Can be able to absorb vibration and noise. It is insoluble to hydrophilic solvents such as water, acetone, and alcohol. It also has a good surface friction so does not slide more than or less(prenominal) easily.Dis prefer of Raw Natural RubberThe rubber can only be elastic betwixt 10 0C to 60 0C, this delegacy nether hot conditions the rubber would lose its elasticity. The rubber has a low fictile force meaning it tends to bang up if a low meter of ductile stress is put into it. It has a low abrasion tube meaning the rubber will wear out quickly. It has a woeful immunity to any organic compounds this is because It is soluble to organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from hurt trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). Another loss of natural rubber is that it has a slimy impedance to ozone meaning that when the ozone reacts with the ikon bonds it get a lines, this causes a crack.20 The crack then grows steadily because of further ozone attacks so this causes the strength of the rubber to decrease massively and cause it to join. Another hurt of natural rubber is it has a poor UV resistance this also manner that when it reacts with the double bond it breaks this also means that cracks will from causing the tensile strength to be severely reduced meaning the strength of the rubber would be reduced massively and causing it to break. 20 Another outrage is that vulcanization of the rubber can occur spontaneously , so it is hard to curb the raw state of the natural rubber.The vulcanization of Natural RubberTo improve the properties of the natural rubber, the process of vulcanisation is used to do this. Vulcanization is a process that involves adding natural rubber to a curing agent such as sulphur. The process is done to a lower place heat, so by heating system the rubber in the presence of the curing agent the physical and chemical properties of the rubber would be significantly improved. The reason it does is, because when heating the rubber in the presence of the curing agent, the polymer set up atomic number 18 cross-linked by the agent, therefore the free-flowing macromolecules of the polymer chains becomes more rigid.21 Vulcanization must be under controlled condition to obviate creating a massive amount of cross-linking, this means that it will head off make the rubber less elastic and more brittle.Figure 4 Cis-polyisoprene with sulphur cross-links after vulcanization 23Prope rties of Vulcanised RubberThe rubber has a clear colour and it is hard and not sticky, when the rubber is cooled down it crystalizes, so has a well-defined shape. The rubber has a high tensile strength meaning it does not tend to break if a low amount of tensile stress is put into it. It has a high abrasion resistance meaning the rubber will not wear out quickly. It is not soluble to organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). It is insoluble to hydrophilic solvents such as water, acetone, and alcohol. The rubber has a high elastic property, this means that when the rubber is stretched out it gets bigger, but when it is released the rubber goes back into its pilot shape. The rubber can only be elastic between -40 0C to speed of light 0C which is better than what the given temperature feed is for the natural rubber in its raw state, this means under hot conditions the rubber would not lose its elasticity. Another property of the natural rubber is that it does not absorb a large amount of water this means it can be dried easily before the next stage of the process. 23Advantages of Vulcanised RubberThe hardness of the rubber can easily be adjusted, so can be able to shape or coat any form of objects this is because the rubber has a high elastic property, this means that when the rubber is stretched out it gets bigger, but when it is released the rubber goes back into its original shape. It can be used as an electrical conductor or an electrical insulator. Can be able to absorb vibration and noise. It is insoluble to hydrophilic solvents such as water, acetone, and alcohol. It is also insoluble to organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil a ttained by the distillation of coal tar). It also has a good surface friction so does not slide about easily. The rubber has a high tensile strength meaning it does not tend to break if a low amount of tensile stress is put into it. It has a high abrasion resistance meaning the rubber will not wear out quickly. The rubber can only be elastic between -40 0C to 100 0C which is better than what the given temperature range is for the natural rubber in its raw state, this means under hot conditions the rubber would not lose its elasticity. Another advantage of the vulcanize rubber is that it does not absorb a large amount of water this means it can be dried easily before the next stage of the process. It has a better resistance to ozone and UV this means that less cracks form than in its raw state. This means that it is less believably to break than the raw natural rubber.Disadvantages of Vulcanised RubberIf the change rubber is burned it can be toxic for the workers and consumers th is is because it contains sulphur cross-links which can form sulphur dioxide. Vulcanization must be under controlled condition to avoid creating a massive amount of cross-linking, this means that it will avoid making the rubber less elastic and more brittle. Another disadvantage of vulcanized rubber, is that when you heat the rubber it melts and then cools quickly, this is quite dangerous for the people who argon handling it. Another disadvantage of using vulcanized rubber, is natural rubber are becoming more scarce, therefore the cost of making the vulcanized rubber is increasing. To overcome this problem, scientist have been trying to make vulcanized rubber out of synthetic rubbers such as styrene-butadiene rubbers (SBR), however the problem with this is that it is not cost effect and it is very expensive to make.24Applications of Natural Rubber and vulcanise RubberThe main usage of natural rubber is in the push industry. It is used to make tyres and tubes in vehicles this is be cause it decreases any generation of heat in the tyres. It also offers high mechanical resistance. Tyres and tubes are used mainly in heavy duty vehicles such as trucks and tractors. 23 Natural rubbers can be used to make toys, footwear, balloons, glue and condoms. Another important application of natural rubbers is that they can be used to make latex gloves. Latex gloves are used in many industries such as the aesculapian industry, chemical industry, and engineering industry, this is because due to the chemical and physical properties of the natural rubber mentioned above it can protect workers and consumers hands from hazardous chemicals.25There are several applications for the vulcanized rubber. Vulcanized rubbers are much better to produce tyres than natural rubber this is due to having high abrasion resistance meaning tyres wont wear out quickly. The rubber is flexible, this means that it can be used to make hoses, tubes, coats etc Shock absorbers in vehicles are made from vul canized rubbers due to being able to absorb vibrations easily.26 As the rubber, does not dissolve in water, it can be used to make waterproof garments and footwears. Another application of using vulcanized rubber is that they can be used to produce cables for telephone housing, and can be able to produce insulations and conductors for electrical instruments. The reason why they are used in electrical instruments, is that have good electrical insulating and conducting properties.Synthetic RubbersSynthetic Rubbers are made by copolymerising two different monomers under certain conditions. There are 3 conditions (the mixture can be in) it can be done in such as emulsion, suspension and solution. There are 9 major classes of synthetic rubbers Styrene-butadiene rubber (SBR), Poly(Butadiene-acrylonitrile) rubbers (NBR), Butyl Rubbers (IIR), Polychloroprene (CR), Ethylene-propylene rubbers (EPDM), Urethane rubbers (EU), Silicone rubbers (VMQ), Fluoroelestomer (FKM), Flurosilicone (FVMQ).2 7 In this 4 major classes are being discussed.PolychloropreneIn 1930, an American scientist named Wallace Carothers and his team produced a compound called chloropropene which then polymerised to form a solid which had a rubbery texture. The team had found out that the properties of this new polymer was similar to that of natural rubber. This polymer was named as Neoprene and was the first commercially successful synthetic rubber.13Neoprene is produced by the free-radical polymerisation of chloroprene. The chloroprene undergoes polymerisation under aqueous emulsion.28Properties of PolychloropreneThe rubber has a greyish green colour.28 The rubber has a high tensile strength meaning it does not tend to break if a low amount of tensile stress is put into it. It has a high abrasion resistance meaning the rubber will not wear out quickly. It can dissolve with organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, pet rol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). It is insoluble to hydrophilic solvents such as water, acetone, and alcohol. The rubber has a moderate elastic property, this means that when the rubber is stretched out it gets bigger, but when it is released the rubber goes back into its original shape. The rubber can only be elastic between -34 0C to 100 0C which is better than what the given temperature range is for the natural rubber, this means under hot conditions the rubber would not lose its elasticity. The rubber has a low flammability, and has a high resistance to stomach and ozone.29Figure 5 Polychloroprene 30Advantages of PolychloropreneThis rubber is tougher than natural rubber because it has a higher tensile strength than natural rubber meaning it does not tend to break if a low amount of tensile stress is put into it. It has a very high resistance to hot conditions and other weather conditions this means that it does n ot melt or break easily. Another advantage of polychloroprene rubber is that they have a better resistance to ozone and UV this means that less cracks forms than in its natural counterpart. This means that it is less likely to break than the natural rubber. It has a low flammability and can be able to self-extinguish if it is on fire. The structure of the polychloroprene can be altered to create a new compound which can bear witness different chemical and physical properties.Disadvantages of PolychloropreneThe rubber has a poor resistance to aromatic compounds such as benzene derivatives, they also have poor resistance to carbonyl compounds such as ketones and esters, and, also has a poor resistance to strong oxidising agents. Another disadvantage of polychloroprene, is that they are quite expensive to produce. 29 common applications of PolychloropreneProduction of hosesmaking belts qualification cable covers for electrical instrumentsStyrene-butadiene RubberIn the 1930s, a German chemist named Walter bock had developed a new synthetic rubber which had better properties than that of natural rubber. He first tried to copolymerise dimethyl butadiene with isoprene and butadiene, this was successful as the new polymer had similar properties to the natural rubber. He then replaced dimethyl butadiene with styrene and copolymerised with butadiene, the polymer was named as SBR (styrene-butadiene rubber).14Styrene-butadiene Rubber is produced by the free-radical polymerisation of styrene heterogeneous with butadiene. The monomers undergo free- radical polymerisation under aqueous emulsion. The monomers can also undergo polymerisation in the form of solution.31Properties of Styrene-butadiene RubberThe rubber has a brown -black colour. 31 The rubber has a high tensile strength meaning it does not tend to break if a low amount of tensile stress is put into it. It has a high abrasion resistance meaning the rubber will not wear out quickly. It can dissolve with organic so lvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). It is soluble to hydrophilic solvents such as water, acetone, and alcohol. The rubber has a moderate elastic property, this means that when the rubber is stretched out it gets bigger, but when it is released the rubber goes back into its original shape. The rubber can only be elastic between -45 0C to 100 0C which is better than what the given temperature range is for the Polychloroprene, this means under hot conditions the rubber would not lose its elasticity. 29Figure 6 Styrene-butadiene rubber 32Advantages of Styrene-butadiene RubberThis rubber is tougher than natural rubber because it has a higher tensile strength than natural rubber meaning it does not tend to break if a low amount of tensile stress is put into it. It has a high abrasion resistance meaning the rub ber will not wear out quickly. Another advantage of styrene-butadiene rubber is that it is much more cost effective than natural rubber, and the production of the rubber is much more efficient than its natural counterpart.Disadvantages of Styrene-butadiene RubberIt has a poor resistance to any organic compounds this is because It is soluble to organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). Another disadvantage of natural rubber is that it has a poor resistance to ozone meaning that when the ozone reacts with the double bonds it breaks, this causes a crack. The crack then grows steadily because of further ozone attacks so this causes the strength of the rubber to decrease massively and cause it to break. Fillers like carbon black are needed to strengthen the rubber.Typical applications of Styrene-butadiene RubberProduction of car tyresMaking matsMaking shoe solesPoly(Butadiene-acrylonitrile) rubbersIn 1931, scientists IG Farben developed a synthetic rubber which consisted of copolymerising acrylonitrile with butadiene, the polymer was known as NBR (Nitrile-butadiene rubber), it was the later known as Buna-N for commercial purposes. 14Styrene-butadiene Rubber is produced by the free-radical polymerisation of styrene mixed with butadiene. The monomers undergo free- radical polymerisation under aqueous emulsion.14Properties of Poly(Butadiene-acrylonitrile) rubbersThe rubber has a yellowish colour.33 It has a high abrasion resistance meaning the rubber will not wear out quickly. It is insoluble with organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). It is insoluble to hydrophilic solvents such as water, acetone, a nd alcohol. The rubber has a good elastic property, this means that when the rubber is stretched out it gets bigger, but when it is released the rubber goes back into its original shape. The rubber can only be elastic between -34 0C to 121 0C which is better than what the given temperature range is for the Polychloroprene, this means under hot conditions the rubber would not lose its elasticity. However, at low temperature, the rubber loses its elasticity.29Figure 7 Poly(Butadiene-acrylonitrile)34Advantages of Poly(Butadiene-acrylonitrile) rubbersIt has a very high resistance to hot conditions and other weather conditions this means that it does not melt or break easily. Another advantage of Poly(Butadiene-acrylonitrile) rubber is that they have a better resistance to ozone and UV this means that less cracks forms than in its natural counterpart. This means that it is less likely to break than the natural rubber. It has a high abrasion resistance meaning the rubber will not wear out quickly. Another advantage of Poly(Butadiene-acrylonitrile) rubber is that it has a high resistance in oil this is because It is insoluble with organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). 29Disadvantages of Poly(Butadiene-acrylonitrile) rubbersAt low temperature, the rubber loses its elasticity. Another disadvantage of Poly(Butadiene-acrylonitrile) rubbers, is that they have poor resistance to carbonyl compounds such as ketones and esters, and, also has a poor resistance to strong oxidising agents. 29Typical applications of Poly(Butadiene-acrylonitrile) rubbersMaking nitrile glovesCan be used for O-ringsCan be used to make hoses and tubingEthylene propylene Terpolymer RubberIn the 1960s, EPDM (which is known as Ethylene propylene Terpolymer Rubber) was produced. The rubber is made by copolymerising by a diene derivative, ethylene and propylene. The rubber has many advantageous properties over the synthetic rubbers, one of them is that they have good electrical insulating properties. EPDM rubber are now found in our everyday life such as hose, solar panels, electrical insulation etc. 16Ethylene propylene Terpolymer Rubber is produced by the copolymerisation of ethylene, propylene and a diene derivative. The monomers under copolymerisation in the form of solution.Figure 8 EPDM 35Properties of Ethylene propylene Terpolymer RubberThe rubber has a yellowish colour. It has a high abrasion resistance meaning the rubber will not wear out quickly. It is insoluble with organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar). It is insoluble to hydrophilic solvents such as water, acetone, and alcohol. The rubber has a goo d elastic property, this means that when the rubber is stretched out it gets bigger, but when it is released the rubber goes back into its original shape. The rubber can only be elastic between -40 0C to 149 0C which is better than what the given temperature range is for the Poly(Butadiene-acrylonitrile) rubber, this means under hot conditions the rubber would not lose its elasticity. 29Advantages of Ethylene propylene Terpolymer RubberIt has a very high resistance to hot conditions and other weather conditions this means that it does not melt or break easily so does not age very easily. Another advantage of Ethylene propylene Terpolymer rubber is that they have a better resistance to ozone and UV this means that less cracks forms than in its natural counterpart. This means that it is less likely to break than the natural rubber. It has a high abrasion resistance meaning the rubber will not wear out quickly. The rubber is very cost effective, so it is cheaper to make than the other rubber compounds. 29Disadvantages of Ethylene propylene Terpolymer RubberIt has a poor resistance to oils, this is because It is insoluble with organic solvents such as turpentine (which is an oiled that is attained by the distillation of resin from pine trees), ether, petrol, carbon tetrachloride, and naphtha (which is an oil attained by the distillation of coal tar).29Typical applications