WHAT IS THE DIFFERENCE BETWEEN LATEX AND RUBBER?
Are rubber and latex the same thing? The words “latex” and “rubber” are used together so frequently that some assume they’re interchangeable. Many even wonder, “Is latex natural rubber?” or “Is rubber latex?” However, latex and rubber are two different materials with numerous variations to consider.
WHAT IS LATEX
Many people think latex is another word for rubber. But latex material and rubber are not the same thing. Natural Rubber Latex is a milky white substance that may be used in production as is or collected, treated, and processed to become rubber.
Latex in itself is almost gelatinous by nature. A good comparison would be a particularly thick batch of cake frosting. Depending on the manufacturing of this material, it can be thin enough to wear as clothing or developed further into much more substantial rubber products such as tires.
WHAT IS LATEX MADE OF?
You may be wondering “how is latex made?” or “where does latex come from?” Latex can be loosely classified into two categories: natural latex and synthetic latex.
Natural latex comes from many flowering plants, including Hevea brasiliensis, the “rubber tree.” The milky white latex is found directly under the bark of the rubber tree and is harvested via careful tapping methods perfected over many years.
Synthetic latex, however, is made entirely by humans. Most synthetic latex comes from styrene and butadiene, two common petroleum compounds, but other petrochemicals may be used. Synthetic latex mimics many of the most desirable properties of natural latex. It’s also worth noting that synthetic latex is usually safe for people sensitive or allergic to natural latex.
USES OF LATEX
Most latex is processed into rubber, but latex has many uses as a pure substance.
Synthetic latex is in high demand for coatings, paints, and glues. The polymer particles in the latex coalesce and solidify as the substance dries, creating a protective film that is safe for the environment. Synthetic paints and coatings are especially popular for outdoor use.
Latex may also be used in clothing, chewing gum, and drug development.
WHAT IS RUBBER?
Rubber is a polymeric substance that can be loosely categorized into three types:
NATURAL RUBBER
Natural rubber is the product of natural latex and offers many highly desirable properties. It’s strong, flexible, and durable. Rubber protects well against wear and tear, such as abrasion, fatigue, and exposure to water and certain chemicals. Every natural rubber product will have a slightly different composition profile based on its service environment, but natural rubber ingredients include latex, acids, chemicals, and additives.
Natural rubber comes from natural rubber latex harvested from rubber trees. The milky white latex is first treated with a coagulating agent and dried. The dried material is then exposed to heat, which triggers vulcanization. Additives may also be introduced at this stage to enhance material properties, improve durability, or increase resistance to environmental stressors.
SYNTHETIC RUBBER
Synthetic rubber comes from synthetic latex, which comes from petroleum byproducts. Synthetic rubber is relatively easy to produce and readily available. While there are many similarities between synthetic and natural rubber, there are a few key differences. Synthetic rubber is more resistant to abrasion, grease, oil, and heat when compared to natural rubber. Some varieties of synthetic rubber are even flame-resistant. Like natural rubber, synthetic rubber is highly flexible, but synthetic rubber maintains that flexibility even at low temperatures. With the proper manufacturing methods, synthetic rubber can also be highly resistant to extreme temperatures and corrosion.
Synthetic rubber is also the product of coagulation and heat. However, synthetic rubber manufacturing starts with a hydrocarbon mixture, usually from oil or coal. This mixture is refined to produce naphtha, a flammable oil. The naphtha is combined with natural gas to create monomers, such as butadiene, styrene, isoprene, chloroprene, ethylene, and propylene. This substance is then polymerized using a catalyst and process steam, forming chains of polymers to create rubber. At this stage, the synthetic rubbers can be further vulcanized if needed.
SILICONE RUBBER
Silicone rubber, like natural rubber, is an elastomer. The difference between the two lies in their atomic structure. Most rubbers have backbones made of carbon-carbon bonds, but silicone’s backbone is silicon and oxygen. Silicone is typically non-reactive, stable, and resistant to extreme environments. Silicone rubber holds up much better than natural rubber against heat, cold, chemicals, and ozone. Silicone also can handle long-term water exposure with minimal absorption or other impact on mechanical properties. Other benefits include biocompatibility and radiation resistance.
Silicone rubber starts with silica, a silicone dioxide compound. Silica can be found throughout the natural world but is most easily extracted from quartz sand. Vast quantities of quartz sand are heated up to 1800°C to extract silicon atoms. The pure silicon is then combined with methyl chloride, exposed to heat, and distilled into polydimethylsiloxane. The final steps of the process include polymerization, molding or extrusion, and curing.
USES FOR RUBBER
Natural rubber can be found in thousands of products, from industrial components to everyday consumer items, including hoses and belts, medical devices, protective gloves, and children’s toys. The tire industry consumes much of the world’s natural rubber supply, and natural and synthetic rubbers can be found in most vehicles.
There are many types of synthetic rubber, and their uses are primarily informed by their unique properties. For example, polyisobutylene rubber, or “butyl,” has excellent damping properties and is commonly used to make massive seismic absorbers for skyscrapers in cities prone to earthquakes. Ethylene propylene diene rubber (EPDM) protects against environmental factors, making it a popular choice for weather stripping, roofing, and seals. Styrene butadiene rubber (SBR) is an excellent all-purpose synthetic rubber and can be found in tires, shoe soles, and more. The applications for synthetic rubber are virtually unlimited.
Silicone rubber doesn’t degrade in high temperatures and is food-safe, making it a popular choice for cooking and baking tools. Silicone muffin tins, spatulas, and many other tools have become increasingly popular. Many other consumer products contain silicone, such as sportswear, storage containers, electronics, cosmetics, and footwear. Industry uses for silicone include automotive products, sealants, and insulators. Silicone can also be found in many medical products, such as tubing, syringe components, fluid management components, and more.
Importance of Testing Rubber Materials
The potential for rubber and latex is as vast as the potential of human imagination. However, despite its capabilities, when developing a product, designers must use the proper form of rubber for the task for optimum results. Certain rubbers are better suited for specific jobs.
For example, EPDM rubbers excel at handling high heat levels, whereas others, like NBR, are best utilized for their natural sealing capabilities against oils and fuels. Suppose you are unsure whether or not you used the appropriate rubber in your newest innovation. In that case, it is better to take the guesswork out and have your selected rubber professionally tested by experts like Ace Laboratories. They will perform extensive rubber testing to ensure your product will operate as intended and provide its necessary service.
However, if you are unsure what rubber you have used, that’s alright, too. Many laboratories, such as Ace, offer Polymer ID services to provide further information on your product’s nature and offer peace of mind as your project progresses.
RUBBER TESTING SERVICES FROM ACE LABORATORIES
The experts at ACE have years of experience working with natural, synthetic, and silicone rubber materials and products of all kinds. Our state-of-the-art ISO/IEC 17025 accredited laboratory is equipped to support industry standard testing and comprehensive, custom testing protocols. Whether you’re looking to assess a raw material or investigate a whole product, our team can help.