Polyisoprene natural rubber. This article will delve into the essential properties, production methods, and uses of polyisoprene, providing a comprehensive understanding of this versatile material. It is primarily composed of cis-1,4-polyisoprene, a natural polymer that gives rubber its unique properties. It mainly consists of cis-1,4-polyisoprene. The non-rubber constituents of NR are constituted of carbohydrates, fatty acids, phospholipids, proteins, and inorganic substances. Car parts like belts, hoses, and gaskets are made from polybutadiene because it stands up to cold temperatures better than other elastomers. To learn lots more about natural rubber, when and how it was used, and the politics behind the invention and use of synthetic rubber, go on our oh-so-cool virtual Rubber Expedition ! Polyisoprene is diene polymer, which is a polymer made from a monomer containing two carbon-carbon double bonds. Rubber tree plantation in Thailand Rubber, also called India rubber, latex, Amazonian rubber, caucho, or caoutchouc, [1] as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand and Indonesia are two of the leading rubber producers. Finally, in 1955, the Goodyear Tire & Rubber Company developed a synthetic polyisoprene that matched the properties of natural rubber – alleviating our dependence on a resource from the other side of the world. Types of polyisoprene that are used as natural rubbers are classified as elastomers. Oct 17, 2024 · Polyisoprene is a synthetic polymer that mimics natural rubber, with a backbone chain composed of repeating isoprene units. Polyisoprene is a naturally occurring polymer composed of repeating isoprene units. It is recognized as a strategically important material for military and economic purposes. The disadvantages of natural rubber are poor impermeability to gas and steam, poor ageing performance when exposed to heat and air, release many substances by Protein Free (Synthetic Polyisoprene) Natural Rubber represents a synthetic polyisoprene which does not contain protein, which can cause allergic reactions in some cases. Light Tan in color. 5 days ago · Manufacturer of polyisoprene rubber including open cell sponge natural for the appliance, automotive, consumer products, construction, electrical, glass, HVAC (heating ventilation, and air conditioning), and hydraulics industries. Polyisoprene compounds, like those of natural rubber, exhibit good building tack, high tensile strength, good hysteresis, and good hot tensile and hot tear strength. from publication: Waste Rubber Mar 22, 2022 · Polyisoprene is an elastomer material that is widely used in a variety of industries. Natural rubber is a polymer called polyisoprene, which is naturally produced from the sap of the rubber plant. Natural rubber is an elastic polymer, built on isoprene as its monomer. Similarly, the rubber formed from trans-polymerization is called Synthetic Rubber. For more on cis-trans isomerism. Because of certain characteristic properties, they are also used by numerous apparel and textile manufacturers. Here, we prepare synthetic rubber with tensile strength identical to that of natural rubber as a result of our discovery that natural rubber is a naturally occurring nanocomposite with proteins and lipids. In the past two decades, details of the rubber chain Material Data Sheet | Natural Rubber & Polyisoprene Natural Rubber & Polyisoprene has high resilience, good compression set, and molding properties. Natural rubber is polyisoprene in which monomer units are of isoprene i,e 2-methyl-1,3 butadiene. Benefits of Synthetic Polyisoprene Synthetic polyisoprene shares many highly desirable properties with natural rubber latex, such Jul 15, 2022 · One such by-product is isoprene, which is polymerized to produce cis-1,4-polyisoprene—a synthetic version of natural rubber. It closely mimics natural rubber’s characteristics due to its similar polymer structure, rendering it an invaluable player in various industrial applications. 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. Natural Rubber (NR) is harvested as latex from Hevea rubber trees. Oct 13, 2023 · Natural rubber (NR) is a well-known biopolymer used for almost eight centuries. Jun 12, 2023 · Natural rubber is a naturally occurring nanocomposite with an island-nanomatrix structure. It's a lot like natural rubber, polyisoprene. Dec 14, 2023 · to Elastomers to Properties of polymers Elastomer Polyisoprene (natural rubber) (submitted by the website administration) Jan 23, 2022 · Natural rubber is a naturally occurring latex with the long-chain polymer of cis polyisoprene. Synthetic polyisoprene is produced with a synthetic version of the primary chemical constituent of natural rubber latex. Silicone, on the other hand, is an industrial material with a polymer structure containing silicon, carbon, hydrogen and oxygen. The For instance, natural rubber is a milky liquid, while isoprene rubber is a tough, leathery resin in natural and synthetic balata or gutta-percha. Natural Rubber (cis 1-4 polyisoprene): Natural rubber is obtained by coagulation of the latex of a tree known as the Heveas Brasiliensis. Adapted with permission from [12]; copyright 2019 Elsevier Ltd. The characteristics which differentiate polyisoprene from natural rubber arise from the former's closely controlled synthesis. Jun 14, 2021 · As compared to natural rubber latex, polyisoprene offers better processability and consistency, which lends itself to higher manufacturing efficiency and value. The monomer of Neoprene is 2-chloro-1,3-butadiene, it is commonly known as chloroprene. The sole commercial source of natural rubber latex sap is Hevea brasiliensis, commonly called the rubber tree, and is an important raw ‧Natural Rubber (Polyisoprene) The original natural material which has been in commercial use since the turn of the century. Industries such as automotive, medical Polyisoprene compounds, both natural (from trees) and synthetic, are noted for outstanding resilience, and resistance to tear and abrasion. Occurrence of Polyisoprene in Living Organisms cis -Polyisoprene in Higher Plants trans -Polyisoprene in Other Higher Plants and Grasses cis- Polyisoprene in Mushrooms Natural Rubber from H. Neoprene is a synthetic rubber. Synthetic polyisoprene contains no allergenic latex proteins but offers the same excellent performance properties as natural rubber latex. 2600. Sep 26, 2017 · Natural rubber is a polymer of hydrocarbon subunits called isoprenes; consequently, it's sometimes referred to as polyisoprene. Both synthetic polyisoprene and natural rubber are highly elastic and consequently used to make tires and a variety of other applications. Available in standard and custom sizes with alternatives in Kalrez®, Canrez®, Chemraz®, and Parker® materials. Although it has good mechanical properties but these are unfortunately coupled with some drawbacks. This substance has a variety of natural additives, such as proteins and sugars. Isoprene (2-Methyl -1, 3-butadiene) undergoes cis-polymerization to form natural rubber Structure of Natural Rubber (Cis Polyisoprene) Oct 15, 2021 · Natural rubber (NR, cis -1,4-polyisoprene) is applied in over 50,000 products. Elastomer Inc. Polymer processing operations often present numerous safety hazards. These results are leading researchers to conclude that, in addition to the nearly 100% cis-1,4 polyisoprene microstructure, the non-rubber constituents in natural rubber contribute significantly to the unmatched properties of natural rubber in industrial products such as tires. Carbon black is often added in DPR LIQUID NATURAL RUBBER GRINDING WHEELS TIRES TIRE MODIFIER POLYMER BINDER RHEOLOGY LUBRICANT SEALANT ADHESIVE Oct 28, 2022 · Synthetic polyisoprene contains no allergenic latex proteins but offers the same excellent performance properties as natural rubber latex. *HNBR, Epichlorohydrin(ECO), Polyacrylate (ACM), Ethylene Acrylic (AEM) can be grouped similar to NBR due to similarities in polymer types. Natural rubber is a polymer of the molecule isoprene whose structure is seen to the left in Figure 1. ) belonging to the Euphorbiaceae family is currently the only commercial source of NR. The synthetic form of this rubber is 1. The Synthetic Polyisoprene Featuring superb physical properties and latex-allergen free, synthetic polyisoprene is a great alternative compound to natural latex for dip-molded products. Because of its elasticity, resilience, and toughness, rubber is the basic constituent of the tires used in automotive vehicles, aircraft, and bicycles. natural rubber latex. Natural rubber is waterproof and thus compatible with water in most Jun 20, 2020 · Natural rubber (NR), principally comprising cis -1,4-polyisoprene, is an industrially important natural hydrocarbon polymer because of its unique physical properties, which render it suitable for manufacturing items such as tires. The trans isomer can be isolated from some plants as gutta purcha or balata. In latex, NR is enclosed in rubber particles Polyisoprene Rubber / IR of ENEOS Materials. : 9003-31-0 Molecular Weight： 68. Jan 1, 2022 · Natural rubber (NR) is an essential material with distinct properties that is employed in a wide range of engineering applications, such as tires, rubber springs, vibration mounts, and others [1]. Synthetic rubber is artificially produced from a variety of polymers which provides the rubber its properties. What is Cis-Isoprene? Natural rubber, chemically, is a cis -1,4-polyisoprene polymer composed from isopentyl pyrophosphate monomers; usually with a C15 trans tail derived from the original initiating allylic pyrophosphate (a specific type of diphosphate). Made in the USA. 5 days ago · Natural Rubber Versus Synthetic Production Polyisoprene originates from two distinct sources: natural rubber derived from trees and synthetic material manufactured in chemical plants. The artificially manufactured kind is designated isoprene rubber (IR) and is made up of isoprene (2-methyl-1,3-butadiene) as a monomer. While both polymers offer many of the same physical and chemical qualities and can both be a great fit for several applications, they do present some major differences that can make one better suited than the other for specific uses. Jul 22, 2025 · Polyisoprene, a synthetic or natural polymer of isoprene (C₅H₈), is prized for its rubber-like elasticity and low hysteresis. , automotive tires, owing to its outstanding mechanical and tear properties. also manufactures and supplies high quality latex-free (synthetic polyisoprene) products to meet customer requirements and specifications. The pará rubber tree (Hevea brasiliensis Muell. There are two types of polyisoprene: cis-polyisoprene, which is a natural rubber obtained from the tree Hevea brasiliensis, and trans-polyisoprene, produced by Pallaquium gutta. Natural rubber is obtained in the form of solid particles suspended in a milky white liquid (called latex) that drips from the bark of certain tropical and subtropical trees. I am wondering if the polyisoprene is made from resins of balata or gutta-percha, because it is mentioned that it is made from natural rubber, or is its whole production synthetic? The rubber formed from cis-polymerization is called cis-Polyisoprene or Natural Rubber. Polyisoprene is a biopolymer based on rubber bridges (Figure 10. Arg. Typically, natural rubber is treated to make it less sticky and more durable through a process called vulcanization. Mar 5, 2025 · Natural rubber produced by plants, known as polyisoprene, consists of isoprene units (C 5 H 8) n linked together in a 1,4 cis -configuration 1, 2, 3, 4, which is the Feb 2, 2023 · One of the most significant polymers for human society is natural rubber (NR), which is made of long isoprene polymer chains. The most widely developed rubber with a huge range of compounds available. Natural rubber is an environmentally desirable material and comes from a naturally sustainable source. 6 days ago · polyisoprene, polymer of isoprene (C 5 H 8) that is the primary chemical constituent of natural rubber, of the naturally occurring resins balata and gutta-percha, and of the synthetic equivalents of these materials. Using natural rubber has many advantages such as high tensile strength, superior resistance to tearing and abrasion, and excellent rebound elasticity. Synthetic cis -1,4-polyisoprene is produced commercially using lithium alkyls or Ziegler–Natta catalysts (see Volume 4, Chapters 3 and 6 Pieces of natural vulcanized rubber at Hutchinson 's Research and Innovation Center in France Latex being collected from a tapped rubber tree, Cameroon Rubber tree plantation in Thailand Types of polyisoprene that are used as natural rubbers are classified as elastomers. Its viscoelastic properties allow it to stretch and return to its original shape, making it highly flexible and durable, better for applications requiring sealing, insulation, and cushioning in various industrial Abstract Natural rubber is a naturally occurring nanocomposite with an island-nanomatrix structure. 'High' cis-polyisoprene, either natural or synthetic, will remain an essential raw material for the rubber industry because of its combination of high strength and high resilience characteristics coupled with a broad-based utility. In the process, sulfur atoms insert themselves between the double bonds Jul 17, 2024 · Synthetic polyisoprene rubber is a versatile elastomer known for its close resemblance to natural rubber in molecular structure and properties. 12 Modify Date. It is synthesized through controlled polymerization processes using isoprene monomers, offering advantages such as excellent elasticity, resilience, and resistance to abrasion and tearing. PolymerProcessing. The polymer is highly stereoregular, no trace of the trans structure being observable. Individuals with Latex allergies Like natural rubber, polyisoprene exhibits high elasticity, allowing it to stretch and return to its original shape. You should obtain advice from an experienced professional or consultant. Jan 27, 2023 · What is Polyisoprene? The term “polyisoprene” refers to a polymer material with a specific base polymer: cis-1,4-polyisoprene. Natural rubber offers superior resilience, tensile strength, and excellent adhesion to fabrics and metals. Polyisoprene is a polymer made from the repeating monomer unit isoprene (C₅H₈). All materials are made with FDA approved ingredients per 21CFR 177. Frequently, also the vulcanized material is referred to as natural rubber. The 1,4 polyisoprene is also a natural product called gutta-percha. This article discusses the general properties of natural rubber. NR is fully biodegradable, its tensile strength, elongation and abrasion resistance is excellent over a wide hardness range and has one of the highest resilience of all rubbers. Thus, the structure and properties of both natural and synthetic polyisoprene rubber are almost similar. It has unique properties, which cannot be matched by synthetic rubber. Jun 13, 2023 · The cis- or trans-form of each polyisoprene that defines each polyisoprene as natural rubber or gutta percha is responsible for the different chemical and physical properties of each material and Spectrum (a) is that of natural rubber or Hevea brasiliensis. Types include die ejection and round profile natural rubber. Polyisoprene Rubber Polyisoprene rubber is known for its remarkable similarity to natural rubber, offering excellent flexibility, resilience, and durability. g. Synthetic polyisoprene and natural rubber latex are commonly used polymers for tubing and dip-molded products. Natural rubber (NR) is predominantly cis-1,4 polyisoprene harvested as a milky fluid called latex from the Hevea brasiliensis rubber tree. : 2023-08-23 13:28 Introduction: Polyisoprene is the polymer known as natural rubber, although it can also be manufactured. Polyisoprene rubber, a synthetic alternative to natural rubber, is widely used in the automotive, medical, and consumer goods industries for products such as tires, seals, and medical devices. Oct 13, 2023 · This review focuses on the synthesis, structure, and properties of natural and synthetic rubber, with a special interest in the synthesis of IR nanocomposites, giving the reader a comprehensive reference on how to achieve a mimic of NR. The common form of polyisoprene is cis -1,4-polyisoprene, which occurs in the latex of many plants and trees as natural rubber. What is Natural Rubber? Natural rubber is a polymer that belongs to the elastomer family, which means it has the ability to stretch and return to its original shape. In its original form, latex is greasy and sticky. Jan 1, 2022 · Ancient Mesoamericans used natural rubber to make the balls that were used in the Mesoamerican ballgame (3), which had elements of soccer, basketball, and racquetball in it. It is then compounded to mimic many of the properties of natural rubber latex without the risk associated with latex allergies and sensitivities. Canyon Components supplies Isoprene Rubber (Polyisoprene) O-rings, gaskets, and custom parts as a synthetic alternative to natural rubber. com accepts no liability for use or misuse of the information contained herein. Here is the monomer chloroprene in 3-D: Polybutadiene Polybutadiene was one of the first types of synthetic elastomer, or rubber, to be invented. Contact Support Contact Support. Polyisoprene is regarded as a "latex" glove without the harmful protein found in latex which is responsible for latex allergies. These polymers are known for having excellent elongation, rebound, and energy absorption properties. Solvents or softeneres and swelling properties are indicated too. During the Second World War, a substantial increase in its demand was registered, causing several synthesis pathways to be investigated to develop a synthetic substitute. Elite is thinner Natural rubber, also known as polyisoprene rubber, consists of polymers of the compound isoprene as well as impurities from other organic compounds and some water. Polyisoprene (IR) is a synthetic version of Natural Rubber. Forms of polyisoprene that are used as natural rubbers are classified as elastomers. Learn more about synthetic polyisoprene vs. supplies some of the Polyisoprene Surgical Gloves Polyisoprene surgical gloves are made from synthetic polyisoprene which provide similar properties to latex (natural rubber). In fact, polyisoprene has a molecular structure that is very similar to natural rubber. Rubber, elastic substance obtained from the exudations of certain tropical plants (natural rubber) or derived from petroleum and natural gas (synthetic rubber). After compounding and vulcanization, it finds use in various applications, e. Tires are the leading consumer. The biochemical pathway to natural rubber is an enzymatic process in which isoprene as such plays no part. Our natural rubber sheet products combine exceptional physical properties with the inherent advantages of a naturally derived material. Natural rubber (NR), principally comprising cis-1,4-polyisoprene, is an industrially important natural hydrocarbon polymer because of its unique physical properties, which render it suitable for manufacturing items such as tires. Download scientific diagram | Chemical structure of isoprene and natural rubber (NR) (polyisoprene). As a high-performance elastomer, polyisoprene offers outstanding tensile strength, tear resistance, and fatigue durability—making it a critical material for applications where flexibility and reliability are non-negotiable. The most commonly referred to synthetic rubber is synthetic polyisoprene (abbreviated IR), created as a synthetic alternative This chart shows the chemical compatibility and resistance of all popular rubber or elastomer materials. Polyisoprene is built up from the linking of multiple isoprene molecules leading to four isomers, out of which the most important are the cis and trans isoprene. Synthetic Isoprene Rubber: This rubber is produced through the polymerization of isoprene monomers in a lab, mimicking the properties of natural rubber. More resistant to breakage, ultra thin and sensitive, odor free! Excellent alternative for those who are allergic to latex. As latex allergies continue to drive consumer demand for safe alternative compounds, synthetic polyisoprene is a top choice for medical and surgical applications, sports and recreation products, and food and beverage tubing, among others. Based on its specific molecular structure, polyisoprene can be either a highly elastic polymer (elastomer) or a tough, leathery material like gutta-percha. It also usually has the lowest price. DPR-35 DPR-40 DPR-75 DPR-400Liquid Natural Rubber SKYN® is a premium condom made from polyisoprene (natural rubber) - non-latex material that delivers the ultimate sensitivity. 'High' cis polyisoprene capacity worldwide now approaches 1 million tons per annum of which over half is in the USSR. Alternative rubber-producing sources and systems are required to increase the biological and geographic Oct 17, 2014 · Rubbers and elastomers resistance to chemicals, weathering, ultraviolet light and heat and temperature are indicated below. Keywords: mimic of natural rubber; nanocomposites; natural rubber; synthetic polyisoprene rubber. Depending on its molecular structure, polyisoprene can be a resilient, elastic polymer (elastomer), as in the case of natural rubber and isoprene rubber, or a tough, leathery resin 1. In the 1950’s, polyisoprene synthetic rubber (IR) was successfully obtained using petroleum derivatives as starting materials Natural forms of polyisoprene are also used in substantial quantities, the most important being "natural rubber" (99. It is composed of cis-1,4-polyisoprene particles with an average diameter of ~1 μm dispersed in Mar 8, 2022 · The preparation of synthetic rubber with tensile strength identical to that of natural rubber is a long-standing unsolved problem in chemistry despite extensive related research. Led by the plant that manufactured the first synthetic rubber product made in Japan, we provide a stable supply of products with higher quality and competitiveness to the global market. Latex-free products are required for applications involving direct contact with the skin. Caution: The information on this web site may be unreliable, misleading, out-of-date, or just plain wrong. To make it usable technically, the long polyisoprene chains of natural rubber are cross-linked with one another through vulcanization – which involves the addition of sulfur under pressure and heat. Commercial use of polyisoprene dates back We would like to show you a description here but the site won’t allow us. Mfr "synthetic" natural rubber; mfr butyl rubber; copolymer in prodn of Synthetic elastomers /isoprene/ Polyisoprene rubber, also called IR or synthetic natural rubber, is a material that shares many properties of natural rubber. Natural rubber products or Polyisoprene rubber is a collected in the form of latex from the sap of rubber trees and is ideal for engineering applications. In the 1950’s, polyisoprene synthetic rubber (IR) was successfully obtained using petroleum derivatives as starting materials in the presence NATURAL RUBBER Natural rubber can have many different names, Isoprene, Polyisoprene, but is most commonly known as Gum Rubber. Definition Natural rubber is produced from the latex of the Hevea Brasiliensis tree (or from other plant sources). This property makes it suitable for applications where flexibility and resilience are important. It also has a high tear resistance, low crack growth, properties that allow for low-temperature usage, ketones and alcohol. Concluding Thoughts Aug 26, 2021 · Very similar to the natural type, the isoprene rubber undergoes a synthetic process, and its chemical name is cis-polyisoprene. In this article we will be specifically comparing Polyisoprene rubber is defined as a synthetic material that is chemically and physically almost identical to natural rubber, capable of replacing it in most applications. It is composed of cis -1,4-polyisoprene particles with an average diameter of ~1 μm dispersed in a NR is a natural product and is produced from the white milky juice (latex) of the rubber tree. What are the differences between natural rubber vs synthetic rubber? Natural rubber is produced naturally from the native Brazilian plant Hevea brasiliensis. In the 1950’s, polyisoprene synthetic rubber (IR) was successfully obtained using petroleum derivatives as starting materials Isoprene acts as a basic structural unit for the synthesis of natural rubber (polyisoprene), Isoprene Rubber (IR) or synthetic polyisoprene most commonly cis-1,4-polyisoprene with a molecular mass ranging from 100 to 1000 kDa [19]. This synthetic rubber variant finds extensive application Aug 23, 2023 · POLYISOPRENE Iupac Name： 2-methylbuta-1,3-diene CAS No. The polymer from the natural latex is resistant to many solvents and also is easily processed. 14). 99% cis -1,4-polyisoprene), which is derived from the sap of trees. Use this chart to make sure your rubber or O-ring seal material is compatible with your environment. brasiliensis Production of Commercial Natural Rubber and Latex Composition of Natural Rubber Structure of both Chain Ends of Natural Rubber Abstract Natural rubber is a kind of indispensable biopolymers with great use and strategic importance in human society. Polyisoprene Structure Synthetic polyisoprene is produced by the polymerization of isoprene. It is a crucial material for various consumer and industrial products, particularly in the tire manufacturing industry. Known for elasticity, durability, and resilience, Isoprene Rubber is ideal for automotive, medical, and consumer goods applications. However, its production relies almost exclusively on rubber-producing plants Hevea brasiliensis, which have high requirements for growth conditions, and the mechanism of natural rubber biosynthesis remains largely unknown. However, EPDM, like other rubbers, has poor mechanical properties. Presently, industrial NR production depends solely on latex obtained from the Pará rubber tree, Hevea brasiliensis. It is the main chemical constituent of natural rubber, as well as its synthetic counterparts. The natural rubber latex is harvested from the rubber tree, Hevea brasiliensis. Samples available upon request. Jul 4, 2025 · Description Polyisoprene is the polymer known as natural rubber, although it can also be manufactured. Despite the advancement in synthetic rubber research, NR remains as a practically irreplaceable rubber. Jan 2, 2025 · Rubber is a natural polymer derived from the latex of rubber trees, primarily composed of hydrocarbon polymers like polyisoprene. Like other surgical Feb 1, 2023 · Natural rubber (NR) is a naturally produced ∼98% cis 1, 4 polyisoprene, having high mean molecular weight, broad molecular weight distribution with significant gel content, and branching [3]. Feb 15, 2022 · Sadaka and colleagues reported the synthesis of oligomers from synthetic polyisoprene and styrene-butadiene rubber through CM, using it as model to further applications to rubber waste depolymerisation [77]. Introduction Natural rubber (NR) is a well-known biopolymer used for almost eight centuries. It is ideal for many productions. Jan 1, 2015 · Natural rubber is produced from the latex of the Hevea Brasiliensis tree (or from other plant sources). Polyisoprene can be derived from plant-based sources—as natural rubber latex—and petroleum derivatives—as synthetic polyisoprene. Sep 7, 2021 · With the increasing incidence of latex allergy, scientists started producing synthetic polyisoprene rubber as a possible substitute for natural rubber. ⦁ In spite of the inherent fragility of polyisoprene, natural rubber is an essential material with incredible properties. The fact that it is derived from a renewable source, along with its excellent qualities Polyisoprene is typically used in favor of natural rubber in applications requiring consistent cure rates, tight process control, or improved extrusion, molding, and calendering. It is the primary component of natural rubber and has a wide range of applications, particularly in the production of various rubber products. Natural rubber consists mainly of polyisoprene, making it almost identical to synthetic isoprene rubber in terms of its chemical makeup. Its properties are mainly identical to natural rubber. Apr 9, 2024 · A rubber shortage ensued, and not even the most aggressive campaigns to conserve and reduce rubber consumption solved it. Because it is an organic product, Natural Rubber does have more problems with consistency from lot-to-lot than most man made polymers. Describe and draw the chemical reactions that make natural rubber useful. As latex allergies continue to drive consumer demand for safe alternative compounds, synthetic polyisoprene is a top choice for many applications. NR is an entirely 1,4 cis isomer. Cis-polyisoprene has good mechanical properties, like elasticity and softness. ifmf japz zqq0kxl qicji w7 bt7ym1 boys 9jyq s6c 8j