Vulcanization of rubber

• العربية • Asturianu • Беларуская • Беларуская (тарашкевіца) • Български • Bosanski • Català • Čeština • Dansk • Deutsch • Ελληνικά • Español • Esperanto • Euskara • فارسی • Français • Gaeilge • 한국어 • Հայերեն • हिन्दी • Hrvatski • Bahasa Indonesia • Italiano • עברית • Jawa • Қазақша • Кыргызча • Latviešu • Bahasa Melayu • Nederlands • 日本語 • Norsk bokmål • Polski • Português • Română • Русский • Simple English • Slovenčina • Slovenščina • کوردی • Српски / srpski • Srpskohrvatski / српскохрватски • Suomi • Svenska • தமிழ் • ไทย • Тоҷикӣ • Türkçe • Тыва дыл • Українська • Tiếng Việt • Winaray • 吴语 • 粵語 • 中文 Vulcanization (British: Vulcanisation) is a range of processes for hardening Vulcanization can be defined as the The word was suggested by History [ ] Rubber – latex – had been known for thousands of years in Early rubber tube tires in the 19th century would grow sticky on a hot road. Debris would get stuck in them and eventually the tires would burst. [ citation needed] Applications [ ] There are many uses for vulcanized materials, some examples of which are rubber hoses, shoe soles, toys, erasers, hockey pucks, shock absorbers, conveyor belts, Overview [ ] In contrast with • Sulfur systems • • Metallic oxides • Acetoxysilane • Urethane crosslinkers Vulcanization with sulfur [ ] Main article: The most common vulcanizing methods depend on sulfur. Sulfur, by itself, is a slow vulcanizing agent and does not vulcanize synthetic Vulcanization of polychloroprene [ ] The vulcan...

\( \newcommand\) • • • • • • Learning Objectives • Know the properties of rubber. • Describe the process of vulcanization. Natural rubber, also called India rubber or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds, plus water. Thailand and Indonesia are two of the leading rubber producers. Forms of polyisoprene that are used as natural rubbers are classified as elastomers. Isoprene Polyisoprene (rubber) Currently, rubber is harvested mainly in the form of the latex from the rubber tree or others. The latex is a sticky, milky colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". The latex then is refined into rubber ready for commercial processing. In major areas, latex is allowed to coagulate in the collection cup. The coagulated lumps are collected and processed into dry forms for marketing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has a large stretch ratio and high resilience, and is extremely waterproof. In 1832–1834 Nathaniel Hayward and Friedrich Ludersdorf discovered that rubber treated with sulfur lost its stickiness. It is likely Hayward shared his discovery with Charles Goodyear, possibly inspiring him to make the discovery of vulcanization. Thomas Hancock (1786–1865), a scientist and engineer, was t...

The work was aimed at the investigation of influence of peroxide curing system on cross-linking and properties of rubber compounds based on SBR. First, the temperature of vulcanization and the amount of dicumyl peroxide on curing process and physical-mechanical properties were investigated. Then, co-agents Type I and Type II were added to the rubber formulations cured with peroxide. The results revealed that the increase in temperature leads to the acceleration of curing process while both, curing kinetics and physical-mechanical properties were influenced by the amount of peroxide. The application of Type I co-agents resulted in the acceleration of curing process and increase in cross-link density of vulcanizates, which was reflected in the increase of hardness and decrease of elongation at break. The influence of Type II co-agents on curing kinetics was negligible, while most of them caused the reduction in cross-linking degree of vulcanizates. Type I co-agents contributed to the improvement of tensile strength of vulcanizates, while the influence of Type II co-agents on tensile strength was of minor importance. • Previous article in issue • Next article in issue

Vulcanization of rubber Vulcanization of rubber is a process designed to improve the elasticity of rubber and strength via the presence of sulfur and heating, which changes the structure of the rubber molecules. Car tires, the hoses that firefighters use, and rubber bands. These are just a small sampling of the wide range of products that are made with vulcanized rubber. Let’s take a closer look at these transformative processes. Vulcanized Rubber 101 What does vulcanization do? What is vulcanization? Vulcanization is the process of treating rubber or plastic with chemicals so that it becomes stronger, more stable or has more elasticity. In its natural state, rubber is somewhat elastic and not as strong as it could be. During the process, sulfur and other additives – “accelerators” – are introduced in order to create a way to bridge, or connect the polymer chains that already exist in the rubber. Once the rubber has been vulcanized, it can be used commercially due to its durability, strength, and its non-stick properties. There are two processes by which 3 steps to manufacturing vulcanized rubber 1. Pressure Vulcanization This process is the most typical process of vulcanization and involves heating the rubber with the use of sulfur and pressure at 150 degrees C. Other chemicals and agents can be used throughout the process, such as fillers to increase strength and resistance to wear and tear, or carbon black that acts as a reinforcer. 2. Free Vulcanization Free vulcanizat...

Vulcanization Process The vulcanization process that involves sulfur or peroxides with catalysts or high temperature/pressure (depending on the type of elastomer) is necessary and needed to obtain durable and applicable elastomers. From: Carbon-Based Nanofillers and Their Rubber Nanocomposites, 2019 Related terms: • Energy Engineering • Nanoparticles • Nanotubes • Silicon Dioxide • Elastomer • Ethylene-Propylene-Diene-Monomer • Styrene-Butadiene Rubber • Crosslinks • Rubber Composite • Rubber Compound SURFACES, CHEMISTRY & APPLICATIONS JOSÉ MIGUEL MARTÍN-MARTÍNEZ, in Adhesion Science and Engineering, 2002 4.5Curing agents Raw rubber is an entanglement of high molecular weight hydrocarbon chains. Consequently, rubber flows on standing and does not retain its shape. For rubber to become useful, its chains must be permanently linked together to increase its strength. Rubber can be cross-linked (i.e. vulcanized) by heating with sulphur and lead oxide. During vulcanization, sulphur linkages form bridges between rubber chains. The vulcanization process established by Goodyear in 1839 is still currently in use. Sulphur vulcanization takes place in three stages. (1) Induction period. The curatives react with themselves in preparation for the cross-linking reaction. This period allows the ingredients to be safely mixed avoiding premature curing (‘scorch’). (2) Vulcanization of the rubber. Sulphur bridges between rubber chains are actually produced. (3) Reversion. This is undesirabl...

blue and green) with N.B. In this image, the degree of crosslinking is exaggerated for illustrative purposes. The details of vulcanization remain murky because the process converts mixtures of polymers to mixtures of insoluble derivatives. By design the reaction does not proceed to completion because fully crosslinked polymer would be too rigid for applications. It is agreed that the reactive sites, often referred to as 'cure sites', are the 2-). • Excessive crosslinking can convert the rubber into a hard and brittle substance (i.e. • Short crosslinks, possessing lower numbers of sulfur atoms, give the rubber better resistance to heat and weathering. • Longer crosslinks, with higher numbers of sulfur atoms, give the rubber improved physical durability and Sulfur, by itself, is a slow vulcanizing agent and does not vulcanize synthetic polyolefins. Even with natural rubber, large amounts of sulfur as well as high temperatures and prolonged heating periods are necessary, with the end products often being of an unsatisfactory quality. Since the early 1900s, various chemical additives have been developed to improve the speed and efficiency of vulcanization, as well as to control the nature of the cross-linking. Cure package [ ] The cure package consists of various reagents that modify the kinetics and chemistry of crosslinking. These include accelerants, activators, retarders and inhibitors. Sulfur source [ ] Ordinary sulfur (octasulfur, or S 8) is rarely used, despite its low ...

The work was aimed at the investigation of influence of peroxide curing system on cross-linking and properties of rubber compounds based on SBR. First, the temperature of vulcanization and the amount of dicumyl peroxide on curing process and physical-mechanical properties were investigated. Then, co-agents Type I and Type II were added to the rubber formulations cured with peroxide. The results revealed that the increase in temperature leads to the acceleration of curing process while both, curing kinetics and physical-mechanical properties were influenced by the amount of peroxide. The application of Type I co-agents resulted in the acceleration of curing process and increase in cross-link density of vulcanizates, which was reflected in the increase of hardness and decrease of elongation at break. The influence of Type II co-agents on curing kinetics was negligible, while most of them caused the reduction in cross-linking degree of vulcanizates. Type I co-agents contributed to the improvement of tensile strength of vulcanizates, while the influence of Type II co-agents on tensile strength was of minor importance. • Previous article in issue • Next article in issue

Vulcanization Process The vulcanization process that involves sulfur or peroxides with catalysts or high temperature/pressure (depending on the type of elastomer) is necessary and needed to obtain durable and applicable elastomers. From: Carbon-Based Nanofillers and Their Rubber Nanocomposites, 2019 Related terms: • Energy Engineering • Nanoparticles • Nanotubes • Silicon Dioxide • Elastomer • Ethylene-Propylene-Diene-Monomer • Styrene-Butadiene Rubber • Crosslinks • Rubber Composite • Rubber Compound SURFACES, CHEMISTRY & APPLICATIONS JOSÉ MIGUEL MARTÍN-MARTÍNEZ, in Adhesion Science and Engineering, 2002 4.5Curing agents Raw rubber is an entanglement of high molecular weight hydrocarbon chains. Consequently, rubber flows on standing and does not retain its shape. For rubber to become useful, its chains must be permanently linked together to increase its strength. Rubber can be cross-linked (i.e. vulcanized) by heating with sulphur and lead oxide. During vulcanization, sulphur linkages form bridges between rubber chains. The vulcanization process established by Goodyear in 1839 is still currently in use. Sulphur vulcanization takes place in three stages. (1) Induction period. The curatives react with themselves in preparation for the cross-linking reaction. This period allows the ingredients to be safely mixed avoiding premature curing (‘scorch’). (2) Vulcanization of the rubber. Sulphur bridges between rubber chains are actually produced. (3) Reversion. This is undesirabl...

Vulcanization Vulcanization is a chemical process in which the rubber is heated with sulphur, accelerator and activator at 140–160°C. The process involves the formation of cross-links between long rubber molecules so as to achieve improved elasticity, resilience, tensile strength, viscosity, hardness and weather resistance. From: Chemistry, Manufacture and Applications of Natural Rubber, 2014 Related terms: • Rubber • Elastomer • Mechanical Property • Polysiloxane • Thermoplastics • Tyre • Glass Fiber • Ultimate Tensile Strength A.Y. Coran, in The Science and Technology of Rubber (Fourth Edition), 2013 7.1Introduction The vulcanization process is necessary to produce most useful rubber articles, like tires and mechanical goods. Unvulcanized rubber is generally not strong, does not retract essentially to its original shape after a large deformation, and it can be very sticky. In short, unvulcanized rubber can have the same consistency as chewing gum. The first commercial method for vulcanization has been attributed to Charles Goodyear. His process (heating natural rubber with sulfur) was first used in Springfield, Massachusetts, in 1841. Thomas Hancock used essentially the same process about a year later in England. However, Hancock filed his patent on November 21, 1843, 8weeks before Goodyear filed his US Patent on January 30, 1844. Since those early days, there has been continued progress toward the improvement of the process and in the resulting vulcanized rubber article...

blue and green) with N.B. In this image, the degree of crosslinking is exaggerated for illustrative purposes. The details of vulcanization remain murky because the process converts mixtures of polymers to mixtures of insoluble derivatives. By design the reaction does not proceed to completion because fully crosslinked polymer would be too rigid for applications. It is agreed that the reactive sites, often referred to as 'cure sites', are the 2-). • Excessive crosslinking can convert the rubber into a hard and brittle substance (i.e. • Short crosslinks, possessing lower numbers of sulfur atoms, give the rubber better resistance to heat and weathering. • Longer crosslinks, with higher numbers of sulfur atoms, give the rubber improved physical durability and Sulfur, by itself, is a slow vulcanizing agent and does not vulcanize synthetic polyolefins. Even with natural rubber, large amounts of sulfur as well as high temperatures and prolonged heating periods are necessary, with the end products often being of an unsatisfactory quality. Since the early 1900s, various chemical additives have been developed to improve the speed and efficiency of vulcanization, as well as to control the nature of the cross-linking. Cure package [ ] The cure package consists of various reagents that modify the kinetics and chemistry of crosslinking. These include accelerants, activators, retarders and inhibitors. Sulfur source [ ] Ordinary sulfur (octasulfur, or S 8) is rarely used, despite its low ...