Natural rubber (NR) is a cis-1,4-polyisoprene as the main component of the natural polymer compounds, 91% to 94% of its composition is rubber hydrocarbon (cis-1,4-polyisoprene), and the rest for the proteins, fatty acids, ash, sugar and other non-rubber substances. Natural rubber is the most widely used set of universal rubber.
Usually we say natural rubber, refers to the natural latex collected from the Brazilian rubber tree, after coagulation, drying and other processing procedures and made of elastic solid. Natural rubber is a cis-1,4-polyisoprene as the main component of the natural polymer compounds, the rubber hydrocarbon (cis-1,4-polyisoprene) content of more than 90%, but also contains a small amount of proteins, fatty acids, sugars and ash.
Basic introduction Chinese name: natural rubber Foreign name: NR (Natural Rubber) Main components: cis-1,4-polyisoprene Molecular Formula: (C5H8) n Classification: solid natural rubber, concentrated latex Characteristics: resilience, insulating properties, waterproof, plasticity Development history, strategic position, characteristics of the distribution of the composition of the composition of the physical properties of the natural properties, natural rubber Microstructure, Species Classification, Main Uses, Properties, Relevant Information, Transportation and Storage, Producing Countries, Development Status, Rising Possibilities, Rubber Insurance, History 1492 Long before Columbus discovered the American continent, the local inhabitants of Central and South America had begun to utilize it. Natural Rubber 1736 It was not until 1736 that France reported for the first time in the world on the origin of rubber, the method of collecting latex and the local use of rubber in South America, which led to the recognition of natural rubber by the Europeans and the further study of its utilization. 1839 After that, after more than 100 years, until 1839, the American Goodyear (C. Goodyear) found in the rubber to add sulfur and alkali lead carbonate, after heating the rubber products produced by heat or exposure to sunlight, it is no longer easy to soften and sticky as in the past, but also to maintain good elasticity, and thus invented the rubber vulcanization. Rubber vulcanization, to this point natural rubber is really recognized for its special value, become an important industrial raw materials. 1888 British Dunlop (J.B. Dunlop) invented the pneumatic tire, prompting the automobile tire industry to develop by leaps and bounds, which led to a sharp rise in rubber consumption. 1876 British Wickham (H. Wickham) from the mouth of the Brazilian Masson River collection of rubber seeds, transported back to the Royal Botanic Gardens sowing, and in Ceylon (Sri Lanka), Indonesia, Singapore test planting, are successful. This is the beginning of the Brazilian rubber tree settled in the Far East. Since then, the cultivation of rubber industry development is very rapid. 1997 world natural rubber production has reached 6.247 million tons. After the establishment of New China, the scientific and technological workers of China Agricultural Reclamation through scientific practice, broke the so-called 15 ° north of foreign countries for nearly a hundred years is the Brazilian rubber tree planting "forbidden area" of the theoretical, successfully planted in the latitude of 18 ° north of 24 ° north latitude of the vast area of the Brazilian rubber tree, and get a higher output. In 1996, the output of natural rubber reached 420,000 tons, becoming the fifth largest natural rubber producer in the world. Strategic Position The General Office of the State Council issued the Opinions on Promoting the Development of China's Natural Rubber Industry (Guo Ban Fa [2007] No. 10) in 2007, which further clarified the strategic positioning of 'natural rubber is an important strategic material and industrial raw material', affirmed the significant contributions made by China's natural rubber industry, pointed out the problems and challenges in the development of China's natural rubber industry, and proposed the future development of China's natural rubber industry. Challenges, put forward the future development of China's natural rubber industry guiding ideology, basic principles, development goals and specific measures. The Opinions clearly put forward by 2015, China's annual domestic natural rubber production capacity to reach more than 800,000 tons, overseas production and processing capacity of more than 600,000 tons of the target. Opinions" for the rapid and healthy development of China's natural rubber industry clear direction, create a favorable environment, open up a broad working space, which is a new period to guide the development of China's natural rubber industry, an epoch-making programmatic file, has great practical significance and far-reaching historical significance. Characteristics of the distribution of rubber trees native to the western region of the Brazilian Amazon River Basin Mara Yue, now spread to Asia, Africa, Oceania, Latin America, more than 40 countries and regions. Cultivation area of larger countries are: Indonesia, Thailand, Malaysia, China, India, Vietnam, Algeria, Brazil, Sri Lanka, Lai Birea and so on. China's rubber planting area is mainly distributed in Hainan, Guangdong, Guangxi, Fujian, Yunnan, in addition to Taiwan can also be planted, of which Hainan is the main rubber planting area. Evergreen tree with milky sap. Taproot system, ternate compound leaves, leathery entire. Flowers unisexual, monoecious, panicle. Fruit a capsule with oval seeds. Brazilian rubber tree has a large variability and adaptability. Suitable for the average annual temperature of 26 ~ 27 ℃, and there is no absolute minimum temperature of 15 ℃ or less; annual rainfall of more than 2500mm, uniform distribution; average annual relative humidity of more than 80%; soil depth of more than 1m, the surface layer of 20 ~ 30cm containing more than 3% of the organic matter, the soil pH5 ~ 6, the soil texture is best in loamy soils, the groundwater table of 1.5 ~ 2m or more; the altitude of the general 300m Below the altitude of 300m, no windy areas to plant. Natural rubber is extracted from the sap of plants. Although there are more than 2,000 kinds of plants in the world that can produce natural rubber, the large-scale popularization of planting is mainly for the Brazilian rubber tree. The main component of harvested natural rubber is cis-polyisoprene, which has the characteristics of high elasticity, high elongation strength, good tear and abrasion resistance, and easy to be bonded with other materials, etc. It is widely used in the production of tires, adhesive tapes and other rubber products. Brazilian rubber tree like high temperature, high humidity, quiet wind, fertile soil, mainly planted in Southeast Asia and other low latitude areas. Restricted by natural conditions, our country only Hainan, Guangdong, Yunnan and other places where climatic conditions can be planted, the available area of about 15 million mu, has been planted about 14 million mu, the annual output of about 600,000 tons. Natural Rubber Ingredient Composition There are about 2,000 different kinds of plants in the world that can produce polymers similar to natural rubber, and different kinds of rubber have been obtained from 500 of them, but the one that is really of practical value is the Brazilian trilobal rubber tree. When the surface of a rubber tree is cut, the milk ducts within the bark are severed and latex flows from the tree. The latex collected from the rubber tree is diluted and solidified with acid, washed, and then pressed, dried, and packaged to produce commercially available natural rubber. Natural rubber according to different rubber production methods can be made into smoke sheet, air-dried film, crepe sheet, technical grading dry rubber and concentrated latex. natural rubber standard rubber or granular rubber, is a new variety of natural rubber developed in the 1960s. Previously, the common smoke flake, crepe flake, air-dried flake of these traditional products, whether in the grading method, manufacturing methods are bound to the development of natural rubber. Therefore, Malaysia began to implement the standard rubber program in 1965, the use of raw rubber physical and chemical properties based on the classification of the development of the production of granular rubber. Standard rubber refers to mechanical impurities, plasticity retention rate, plasticity initial value, nitrogen content, volatile matter content, ash content, color index and other physical and chemical properties of rubber graded. Standard rubber packaging is also more advanced, generally packaged in polyethylene film with distinctive markings, the package weight is small and easy to move. Malaysia's packaging weight of 33.3kg, China's regulations for the 40kg. Standard rubber grading is more scientific, so this grading method is quickly accepted by the major natural rubber producing countries and international standardization bodies, and has developed a standard rubber grading standards. These standards are generally the same, but not completely consistent. For example, ISO2000 provides for five grades, China's standard GB8081-87, there are four grades. Physical properties Generally flaky solid, relative density 0.94, refractive index 1.522, modulus of elasticity 2 ~ 4MPa, 130 ~ 140 ℃ when softening, 150 ~ 160 ℃ viscous soft, 200 ℃ when the start of degradation. High elasticity at room temperature, slightly plastic, crystalline hardening at low temperature. Good alkali resistance, but not resistant to strong acids. Insoluble in water, low-grade ketones and alcohols, soluble in non-polar solvents such as trichloromethane, carbon tetrachloride and so on. NATURAL PROPERTIES Usually what we call natural rubber is the elastic solid made from natural latex collected from the Brazilian rubber tree, after solidification, drying and other processing procedures. Natural rubber is a cis-1,4-polyisoprene as the main component of natural polymer compounds, the molecular formula is (C5H8)n, the rubber hydrocarbon (cis-1,4-polyisoprene) content of more than 90%, but also contains a small amount of proteins, fatty acids, sugars, and ash. Physical properties of natural rubber. Natural rubber at room temperature has a high degree of elasticity, slightly plastic, with very good mechanical strength, hysteresis loss is small, in a number of deformation of low heat generation, so its flexural resistance is also very good, and because it is a non-polar rubber, so the electrical insulation properties are good. Chemical properties of natural rubber. Because there is an unsaturated double bond, so natural rubber is a chemical reaction ability of strong substances, light, heat, ozone, radiation, flexural deformation and copper, manganese and other metals can promote the aging of rubber, not aging is the Achilles' heel of the natural rubber, but, add the antioxidant of the natural rubber, sometimes exposed to sunlight for two months is still not see much change in the warehouse after three years of storage can still be used as usual. Natural rubber media resistance characteristics. Natural rubber has good alkali resistance, but does not resist concentrated strong acid. As natural rubber is non-polar rubber, only some polar solvents, and in non-polar solvents are dissolved, therefore, its oil resistance and solvent resistance is very poor, in general, hydrocarbons, halogenated hydrocarbons, carbon disulfide, ether, high-level ketones and high-level fatty acids on the natural rubber have a solvent effect, but its solubility is affected by the degree of plasticizing, and low-level ketones, low-level esters and alcohols on the natural rubber is a non-solvent. Natural rubber microstructure The structure of natural rubber is mainly the chain structure of macromolecules, molecular weight and its distribution and aggregation state structure, natural rubber macromolecular chain structural unit is isoprene, the macromolecular chain is mainly composed of polyisoprene, rubber content of more than ninety-seven percent of the content of its molecular chain aldehyde group, an average of one per macromolecular chain, it is the aldehyde group in the occurrence of condensation or decomposition products with protein Reaction to form a branched, crosslinked, making the rubber storage viscosity increases, natural rubber macromolecular chain there are epoxy-based, more active. Natural rubber macromolecule end deduction is generally dimethyl allyl, the other end of the pyrophosphate ester group, end group, the molecular chain of the aldehyde group as well as the polymerization of the elements are very few, in the molecular weight and its distribution of natural rubber molecular weight, its molecular weight range is wider, according to foreign reports, the vast majority of the molecular weight of 30,000 or so, the natural raw rubber, rubber mixing, vulcanized rubber strength is relatively high, the general strength of natural rubber can be up to The general strength of natural rubber can reach three megapascals. The main reason for the high mechanical strength of natural rubber is that it is a self-reinforcing rubber series, when stretching will make the macromolecular chain along the direction of stress orientation to form a crystalline, crystalline grains of amorphous macromolecules play a reinforcing role in the expansion of the strength of the same high for its internal structure of the tiny particles of the tightly coagulated and caused. natural rubber classification of varieties of natural rubber can be divided into two categories according to the form: solid natural rubber (film and granular rubber) and concentrated latex. In daily use, solid natural rubber accounts for the vast majority of the proportion. Film according to the different manufacturing process and shape, can be divided into smoke sheet rubber, air-dried film, white crumpled film, brown crumpled film and so on. Smoke sheet rubber is the most representative varieties of natural rubber, has been the amount of large, set with a wide range of a rubber, smoke sheet rubber is generally graded according to the shape, divided into special, first, second, third, fourth, fifth, etc. **** six levels, less than five levels are listed as such outside the rubber. Granular rubber (i.e., standard rubber) is graded according to the international unified physical and chemical performance, indicators, these physical and chemical properties include impurity content, plasticity of the initial value, plasticity retention rate, nitrogen content, volatile matter content, ash content and color index and so on seven, of which the content of impurities for the dominant indicators, according to the number of impurities into 5L, 5, 10, 20 and 50 **** five levels. China's futures trading market, the Shanghai Futures Exchange natural rubber pact delivery level for the domestic first-class standard rubber SCR5 and imported smoke sheet rubber RSS3, of which the domestic first-class standard rubber SCR5 usually also known as No. 5 standard rubber, the implementation of the State Bureau of Technical Supervision issued by the implementation of the version of the natural rubber GB/T8081 ~ 1999 quality indicators. The imported flake rubber RSS3 implements the "International Standards for Quality and Packaging of Natural Rubber Grades" (Green Book) (1979 edition) determined by the International Rubber Quality and Packaging Conference. Main Uses As natural rubber has a series of physicochemical properties mentioned above, especially its excellent resilience, insulation, water insulation and plasticity, etc., and also has valuable properties such as oil resistance, acid resistance, alkali resistance, heat resistance, cold resistance, pressure resistance, abrasion resistance and so on after appropriate treatment, so it has a wide range of uses. For example, rainboots, warm water bags, elastic bands used in daily life; surgeon's gloves, blood tubes, condoms used in the medical and health care industry; a variety of tires used in transportation; conveyor belts, conveyor belts, acid-resistant and alkali-resistant gloves used in industry; agricultural use of drainage and irrigation hoses, ammonia bags; meteorological measurements of the use of the sounding balloon; scientific experiments with the sealing of the shock-proof equipment; the use of national defense planes, Tanks, artillery, gas masks used in national defense; even rockets, artificial Earth satellites and spaceships and other highly sophisticated science and technology products are inseparable from natural rubber. Performance Modern scientific research results have proved that ordinary natural rubber is isoprene polymerization. (1) the chemical properties of natural rubber natural rubber is unsaturated rubber, easy to vulcanize with the vulcanizing agent (structural reaction), bromine and oxygen, ozone oxidation, cracking reaction, and halogen chlorination, chemical reaction, chemical reaction under the action of catalysts and acids. However, because natural rubber is a polymer compound, so it has the reaction characteristics of alkene organic compounds, such as slow reaction speed, incomplete and uneven reaction, and at the same time have a variety of chemical reactions coexist phenomenon (such as oxidation and cracking reaction and structuring reaction) and so on. Among the various types of chemical reactions of natural rubber, the most important are the oxidative cracking reaction and structuring reaction. The former is the theoretical basis for the plasticizing process of raw rubber, the reason for the aging of the leaf acid rubber; the latter is the theoretical basis for the vulcanization of raw rubber to produce vulcanization. The natural rubber chlorination, cyclization, hydrogenation and other reactions, can be used for the modification of natural rubber. (2) natural rubber has excellent comprehensive physical and mechanical properties natural rubber at room temperature has good elasticity. This is due to the natural rubber molecular chain at room temperature is amorphous state, the molecular chain of good flexibility. Its density is 0.913g/cm, the modulus of elasticity is 2-4MPa, about one-third of steel, while the elongation is 300 times that of steel, up to 1000%. In the range of 0-100 degrees, the resilience of natural rubber can reach more than 50%-85%. (3) heat aging natural rubber at room temperature for high elastomer, glass transition temperature of -72 degrees, slowly softened by heat, 130-140 degrees in the beginning of the flow, about 200 degrees began to decompose, 270 degrees violent decomposition. (4) Resistance to media Media refers to oils, liquid chemicals and so on. Natural rubber is not resistant to cyclohexane, gasoline, benzene and other media, insoluble in polar acetone, ethanol, etc., insoluble in water, 10% hydrofluoric acid, 20% hydrochloric acid, 30% sulfuric acid, 50% sodium hydroxide and so on. It is not resistant to concentrated strong acid and oxidizing potassium permanganate and potassium bicarbonate. (5) good processing performance natural rubber due to the high relative molecular mass, fairly wide distribution of molecular mass, the molecular chain is easy to break, coupled with the existence of a certain number of gel molecules in the raw rubber, so it is easy to plasticize, mixing, calendering, pressing out, molding and so on. Related information Transportation and storage The ship and cabin of the loaded rubber should be clean and dry, and the pipe system in the cabin, the sewage ditch should be smooth, and the cabin cover should be tight. When loading, the rubber should be separated from the metal part of the cabin with cushions, and the cushion material should be clean, dry and complete without broken. Producing countries Producing countries: China, Vietnam, Malaysia, Thailand, Indonesia Development situation So far in the first half of 2012, the domestic rubber industry's main economic indicators continue to maintain a small growth, the main rubber product output growth has shown a sustained positive trend, the industry products out of the *** Goods value growth fell slightly compared with the previous month, the industry's benefit situation continues to maintain a positive trend. Data show that so far in 2012, China's rubber products industry completed industrial output value increased by 6.47% year-on-year, comprehensive tire production increased by 2.59% year-on-year, of which radial tire production increased by 3.13% year-on-year, all-steel radial tire production increased by 6.55% year-on-year, radialization rate of 87.23%, an increase of 0.46 percentage points. At the same time, the industry realized sales revenue increased by 6.26% year-on-year, inventory increased by 7.06% year-on-year, a decrease of 0.12%. Completion of export tire delivery value increased by 11.29% year-on-year, the export rate (value) of 34.23%, an increase of 1.48 percentage points year-on-year with the previous year. Export tire delivery increased by 5.87% year-on-year, the export rate (volume) was 42.83%, up 1.32 percentage points from the previous year. Upward potential Natural rubber prices will not be reduced, but rather the possibility of price increases is very high. Although suppressed by the technical neckline, but the power of the market is still relatively strong, according to the relevant people, speculation, Shanghai rubber upward possibility is still relatively large. Tire companies export with Cost advantage When the rubber upstream prices into a downward spiral, downstream tire profitability is growing. Since the cancellation of the relevant preferential policies, passenger car sales by the overall economic slowdown impact of weak growth, tire manufacturers start rate decline. Rubber is the main raw material of tires, all-steel tires used in the rubber accounted for about 40% -50%, weak demand led to the decline in tire prices at the same time more on its upstream raw material prices have an impact. According to estimates, when rubber prices fell 40%, the domestic cost of sales of truck and bus tires fell about 27%, in the case of tire prices fell less than the cost of the situation, tire companies are still in the downstream demand is not strong situation so that profitability has been improved. And tire companies also ushered in the expiration of the U.S. special protection case this positive factor, making tire companies in the future will appear in the work rate of certain enhancements, tire companies have more cost advantage of exports, boosting demand for rubber. Heavy truck sales are expected to stabilize October heavy truck sales of 44,000 units, an increase of 1.9%, sales for two consecutive months stabilized above 40,000 units, sales stabilized uptrend. Due to the heavy trucks on the consumption of rubber far more than other types of cars, so the heavy truck production and sales data has been the focus of our attention. If the production and sales of heavy trucks rebound momentum, can be substantially favorable to the rubber market. January-October automobile manufacturers cumulative inventory reduction of 40,000 units, of which the October data show that the difference between heavy truck production and sales of 2,546 units, reflecting the side of the manufacturer level is still maintaining a more cautious attitude. But from July onwards, heavy truck production and sales difference in absolute value of a single month has a significant downward trend, showing that manufacturers inventory pressure has been reduced, the end demand for signs of improvement. After the "Golden Nine and Silver Ten" the traditional peak season of consumption, heavy trucks show stabilization and recovery trend, sales have basically bottomed out, the future downward space is quite limited. Domestic heavy trucks due to the technical level and working environment restrictions, the update cycle is basically in 3-5 years, experienced in 2009 and 2010 heavy truck consumption blowout, has gradually entered the peak update, so the market consumption is worth looking forward to. Industry driven economic recovery from the latest electricity consumption growth data can be seen, electricity consumption growth will be sustained, showing that the fourth quarter of the economy is expected to get a mild recovery. Despite the fact that industrial production and demand rebounded in September, the continued decline in electricity consumption was mainly affected by the de-stocking factor. coal, steel and cement prices rebounded in October, showing that the de-stocking process weakened and industrial production expanded. Meanwhile, infrastructure investment has increased, resulting in a sharp rise in heavy industry electricity consumption, and single-day coal consumption has shown a slight improvement since October, signaling a continuation of incremental electricity consumption. As a result, we expect industrial activity to further drive the economic recovery, and GDP is expected to rebound moderately in the fourth quarter. From the above, we can see that the price trend of natural rubber has the potential to rise. When the current storage rubber and domestic production areas to stop the cut period is approaching on the market to play a strong supportive role, Shanghai rubber main two weeks of successive highs, coupled with tire companies export cost advantage, heavy truck sales are expected to stabilize, industry driven economic recovery three factors, the possibility of upward movement of natural rubber is very large. Natural rubber molding mechanical process requirements natural rubber is the main rubber molding rubber. With the open refiner and refiner for refining can get good results. With the open refiner refining, usually low temperature (40-50 ℃) thin pass (roll pitch 0.5-1mm) refining method and segmented refining method is the best. With the refiner plasticizing, the temperature should be below 155 ℃, the time is about 13min or so (depending on the plasticity requirements). Plasticizing time increases, the plasticity of the plasticized rubber increases. But do not over-refining, otherwise the plasticity becomes too high and the physical and mechanical properties decline. Natural rubber plasticizing, often add accelerator M as a plasticizer to improve the plasticizing effect, accelerator M on the opening machine plasticizing and refining machine plasticizing are applicable. Natural rubber plasticizing, in order to make the rubber molecular chain relaxation (commonly known as recovery fatigue) and plasticity uniformity, need to be parked for a certain period of time (4-8h), in order to be used for the next process. At present, the main varieties of natural rubber used in China are: domestic flake rubber and standard rubber, imported flake rubber and Malaysian standard rubber. Due to the different initial Menni viscosity of the above types of rubber, in order to obtain the same plasticity, the required plasticizing time is of course different. The plasticizing time in the order of: imported smoke sheet rubber & gt; domestic smoke sheet rubber & gt; domestic standard rubber & gt; Malaysia standard rubber. Constant viscosity and low viscosity standard Malaysian rubber, oil-filled natural rubber, tire rubber, easy-to-operate rubber with low initial Menni viscosity (generally less than 65) can be mixed directly without plasticizing. Rubber insurance In November 2018, due to the continued low price of rubber, the rubber farmers cut rubber enthusiasm, for this reason, the Department of Finance of Hainan Province and other departments jointly issued a notice to promote the implementation of the price of natural rubber (income) insurance in the whole province of Hainan, once the price of rubber is lower than a certain standard, it will trigger the insurance claims mechanism, to ensure that the income of the farmers is not at risk.