Executive SummaryThe rubber plant; also referred to as ficus elastica, is a broadleaf evergreen tree that is native to India and Southern Asia. In its native habitat the rubber plant can grow up to 55 meters tall, and 2 meters in diameter. The rubber plant produces latex, a thick white paste material that is commonly used to make natural rubber; this process has been replicated for hundreds of years. The rubber plant thrives in vegetation zones of the tropical rainforests, shrubland, and in light tropical forests, but can also be grown indoors as house ornaments.Geography and HistoryRubber plant is native to Southeast Asia. It also can be called “Indian rubber bush” or “Indian rubber tree”. So, we can easily imagine that it comes from India. It is true. Rubber plant does exist in east India. Furthermore, it located in many other countries and areas. It is native to East India, Nepal, Bhutan, Burma, Indonesia, Malaysia and Yunnan province in China. It has become naturalized in Sri Lanka, the US States of Florida and so on.The geographic environment of rubber plant is related closely to the plant’s nature and habits. Rubber plant is a tropical plant. Rubber plant always exists in warm and wet area. It requires the irrigation. Enough water can makes rubber plant larger and denser. It prefers warm and humid growth environment. Rubber plant has the adaptability to resist strong light. Growth suitable temperature should be 15-35 ?, The temperature cannot be less than 5 ? in winter. Wet and acid soil is required. More water makes it lives better. The geographic feature of South Asia is totally satisfied with those characteristics of the rubber plant.The region of rubber plant is really large. It crosses thousands of miles between eight countries. Although rubber plants distribute so many places, rubber plants are similar in different place. For instance, in Yunnan, one of the southwest provinces in China, feral rubber plant does only survive above 800 meters above sea-level and under 1500 meters above sea-level. In Yunnan province, rubber plant prevails in Ruili, Yingjiang, Lianshan, Rongchuan. Those places are either hills or mountains. The temperature in Yunnan is comfortable for rubber plant. Yingjiang is the region which near the river. The air is wet. The average Air humidity is 86%. Amount of precipitation is around 1100 mm per year which is adequate for rubber plant. The conditions are perfect for rubber tree. That is why rubber plant is able to grow and develop there healthily.The history of rubber plant is long. Before 1920, people in southeast Asia used rubber plant to produce latex. Latex is the liquid that extracted from the rubber tree. It is the constant dispersion in an aqueous medium. It is so sticky that people used it to stick thing. Latex is kind of glue in many countries in Asia. However, the output of production comes out so little in a long time. People didn’t use rubber plant for getting latex. So, people found another plant which can make latex more efficiently———Brazilian rubber tree.Brazilian rubber tree was discovered to produce a larger yield. It can produce more latex in a short time. By 1898, a rubber plantation was distributed in Malaya. A field worker in China being the dominant workforce in rubber manufacture in the early 20th century. The Brazilian rubber tree officially imported to south Asia. For producing latex and rubber, the Brazilian Rubber tree totally replaces rubber plant. Brazilian rubber tree helps for producing a lot. It is always the material for producing gloves, medical devices, footwear and so on. Nowadays, 80% the rubber trees are in south Asia and southeast Asia, the top rubber producing countries in 2011 being Thailand, Indonesia, Malaysia, India, and Vietnam.Although rubber plant was not that useful after rubber plant was replaced, it was used for decoration and viewing. Rubber plant is artistic. The gardener was a popular job in the upper level in India and even China. Many rich people in China like to use rubber plants to prove their status in the society as well. They settle the two rubber trees in front of the door. The leaves of rubber plant are pleasing to the eye. The reason of why rich Chinese like to cultivate rubber plant is also interesting. As we know, there are many leaves on the tree. And the shape of leaves looks like the old copper cash in ancient China. After the 1970s, rubber plants became popular everywhere. Most people can afford rubber plant. Many families choose to take a rubber plant. Rubber plant is not only beautiful but easy to cultivate.Ecology The ecologic side of rubber tree is rigorous. Rubber plant used to arise in south Asia originally. The truck is large. Rubber plant has many branch and the branch can touch the ground. When branch attaches the ground, it becomes another truck. Only one rubber plant can be seen like a forest. Rubber plant is a tropical plant. So, the environment of rubber plant should be warm and wet. The appropriate temperature for rubber plant is 15-35?. 20? is the perfect temperature for rubber plant. Rubber plant cannot survive if the temperature is lower than 5?. Lots of leaves will fall down when it’s lower than 8 ?. The high temperature is not a big challenge for rubber plant. It also requires enough sunlight and water. Rubber plant does have the ability to be under the shadow for a short time. Rubber plant is able to hold water. Avoiding drought is necessary. The soil is also important to plant. The soil should be wet acid soil. Today, the environmental problem is a big issue, especially in China. It can be proved by the example of Xishuangbanna, China. Internationally, amount of soil and water loss generally can be accepted below 11m³ / k? · year. Professor Peifang Zhang remote sensing test studies in 2006 have shown that: Xishuangbanna Prefecture of ??water erosion accounted for 29% of the total area. 11.04% was moderate erosion and 17.95% was mild erosion. The erosion area of ??rubber plant forest accounted for only 32% of the total erosion area and both were mild erosion. The data show that there is no obvious correlation between rubber planting and soil loss, mainly because of the strong restoration ability of vegetation in Xishuangbanna Prefecture. The combination of deep root and shallow root trees enhances the penetration of soil water. The litter of ground vegetation is enlarged Soil nutrient cycle and energy flow. Xishuangbanna soil mainly red soil, accounting for 61.07%, and easily lead to soil erosion brick red soil accounted for only 15.65%. According to those data presented by Professor Zhang, rubber plant is facing a difficulty of the environment. The water and soil loss too much in Xishuangbanna. In 2013?Chinese government trys to deal this problem by publishing the policy, which is forcing factories to limit lumbering and reducing the waste of rubber. Biology and ChemistryAlthough the rubber plant’s name is officially listed as ficus elastica, this name is referring to the milky-white sap that comes from the tree. This plant is common in households but can be planted outdoors where the climate permits it. The rubber plant was found to grow naturally in areas such as Sumatra, Malaya, Nepal, and Northeast India. The full height of the plant can be upwards of 100 feet, and grows naturally in warm climates. The optimal conditions for the rubber plant to flourish is around 70 to 90 degrees Fahrenheit, with the humidity sustaining at 80% (21). Once a tree has been measured at a circumference of 20 inches, the tree may be tapped for its latex. The latex is contained and produced in a layer of the bark that contains lactiferous vessels (21). The total lifespan of a rubber trees can be upwards of 35 years, with seven years spent in an growing phase, and will be able to produce raw latex for the remaining 25 years (21). Latex (the common name of the waxy natural rubber sap) is comprised of water and rubber particles, as seen in the diagram above, these particles contain chains of isoprene (C5H8). These particles are arranged in loosely bound chains that slide by each other and can be pulled apart with relatively low effort when initially collected. Once released these chains quickly form back into their original structure, giving rubber its springy properties.The raw form of rubber can’t be used for much until it is processed, which involves several steps or more depending on what the final product is going to be. The process that improves rubber’s strength and increases rigidity is called vulcanization, which fortunately doesn’t involve any volcanoes or men running around red capes. Vulcanization is the addition of sulfur and heat to the latex, which creates links between the long stretchy chains of the raw rubber (18). The history and a more in depth look into vulcanization will be discussed in the next section.ProcessingCharles Goodyear began his journey into the rubber industry at the young age of 33, when he sought out to improve the quality of rubber. Before Goodyear pioneered the vulcanization process rubber tended to lose its shape in the summer months because of the heat, and crack in the winter months. This unpredictable characteristic of rubber brought the rubber industry to its knees by the middle of the 19th century (16). After Charles went through a tour of a rubber factory and saw all the problems that the current method of rubber processing had, he sought out to find a better way over the next five years of his life. Moving from place to place in the New England area, Charles sought out anyone who would invest in his ideas and fund his experiments. Spending nights in prison for his failure to repay debts, Charles was still driven to find a way to stabilize rubber. One day Charles combined some sulfur with rubber, this substance then fell onto his hot stove, and instead of melting, it hardened. After spending time to perfect this new discovery, and eleven total years after he first began his rubber journey, Charles’ patent application was approved for this procedure. The combining of sulfur and heat to harden rubber became known as vulcanization. This revolutionary technique soon became known across the globe and Charles was forced to use his profits to stop other companies from infringing on his patent for vulcanization (16). Charles was 59 years old when he died in substantial debt, but eventually his name became known when the Goodyear company was formed, and the company blimp still displays his name to this day.The process of vulcanization begins with the addition of sulfur, this is key because this causes some of the carbon-hydrogen bonds to break and then reform as carbon-sulfur bonds. These new bonds create links between the chains that give structure and hardens the rubber into shape if put into molds. Accelerators that speed up the vulcanization process were discovered in 1883 by George Oenslger, a chemist working in the United States (17). Accelerators such as zinc oxide or stearic acid can be introduced to the vulcanization process to act as catalysts, which decrease the amount of energy required to initiate the breaking and reforming of the carbon-hydrogen/carbon-sulfur bonds. The process of vulcanization for a batch of rubber varies depending on the product, the main concept being, the more sulfur added, the more rigid the rubber will become. The elasticity of the finished rubber can range from a rubber band to hard battery covers, with the softest rubber materials only contain 10% or less sulfur (18). Quality control also plays a large part in the vulcanization process, if the finished product doesn’t match the specifications needed by the customer, the rubber will not have the properties that allow it to perform the task. For example, if not enough sulfur is added when the product is going to be used as a hard cover or gasket, the rubber will warp or change its shape because the long polymer chains will begin sliding by each other. This quality control is enforced by making small sample batches with the same proportion of components as the main batch. If the small batch fails to meet the specifications needed, the main batch won’t be made, and they’ll continue to adjust the amount of sulfur or accelerants until the specifications needed are replicated by the small batch (18). This ensures no materials are wasted because the accelerants added can be very expensive.There are some hazards that come with the processing of rubber as with any kind of material that needs industrial equipment and materials. Mechanical dangers to workers need to be considered as well since the machinery needed for the mixing and breaking down of rubber need to mix large amounts of rubber at once while using tremendous force. The highest rate of accidents in the rubber industry, according to the Health and Safety Executive, take place in the manual handling portion of the process. The use of accerants is sometimes necessary to speed up the manufacturing process and these can be flammable when in powder form (19). Careful consideration needs to be made with handling these compounds, with dust removal systems and ventilation being recommended in order to avoid any incidents. During the earlier years of rubber processing, there were reports of the inhaled dust causing cancer in the factory workers, these reports have declined since, with the risks having been deemed minimal as long as proper safety procedures are followed and protective equipment is worn (19).The United States Department of Labor reports that the plastics and rubber industry have more than seven hundred thousand employees as of November 2017 (20). Machine setters and those who tend to the vast amount of machinery used in these industries are the most prevalent occupations in the industry. The average hourly pay for all employees of this industry is $22 per hour, and when averaged without supervisor roles, it sits at $17 per hour (20). The average amount of workplace fatalities for the years with data available (2012-2015), is around 14 per year. The Bureau also reports the average rate of injury per 100 factory workers in 2016 was 3.9 (P6). The price, import, and export indexes for these industries have not changed significantly in the last year, showing the strength of the industry and those positions held by its employees to be secure (20).EconomicsThe Rubber plant is used to make natural rubber based products. Some examples of natural rubber based products are: tires, flooring, airbags, and erasers. The total output of natural rubber in 2016 was 12.4 million tones, and because of the success the rubber plant has in its native habitat, Indonesia, Malaysia, Vietnam, China, and Thailand are the top six producers of natural rubber. Within the United States alone the market value for natural rubber is upwards of $40 billion each year, this translates to a demand of 1.2 million metric tons of natural rubber each year, this is about 11% of the total world’s consumption (23). Virtually all natural rubber within the United states is imported from overseas. The high demand for natural rubber within the United states creates greater value for farmers overseas that grow the plant. Asia dominates the world supply of natural rubber. Approximately 92% of total world production in 2016 came from Asia, and to further narrow it down the three largest natural rubber producing countries in 2016 were all in Southeast Asia: Thailand, Indonesia, and Vietnam. 36.8% of the worlds exports come from Thailand making them the largest producer of the rubber plant (23). In second place is Indonesia, and in third is Vietnam. The high demand for natural rubber is fueled by tire production. Tires and tire products make up about 70% of the total consumption of natural rubber (22) . The industries where the rubber plant is commonly used is- automotive and mechanical parts, medical and health-related products, and non-automotive mechanical parts, these industries account for the remaining 30% of market consumption(22). OutlookThe future of rubber comes in the form of synthetic rubber. Currently, natural rubber is mostly mined in Southeast Asia and has caused massive deforestation problems. The deforestation has led to land grab and human rights issues. Certain companies like Michelin are trying to combat this problem by starting campaigns like Michelin’s 2016 zero deforestation policy. Tire manufacturers are responsible for about 75% of rubber used today(1), and creating policies to aid in preventing deforestation from mining rubber can make the future of this useful material more viable. Synthetic rubber is a great alternative to rubber, as it imitates the natural product very well. Synthetic rubber “eliminates several preparatory manufacturing operations, reducing unit labor requirements” (11). One of these operations is called masticating. This process conditions the rubber and requires energy to accomplish. Synthetic rubber does not require this step and arrives ready to process. The synthetic version of this crucial material has the potential to completely replace America’s dependence on Asian rubber. Synthetic rubber is already prominent in today’s marketplace, as over 70% of rubber used in the tire industry is synthetic. As technology advances, synthetic rubber will become easier to manufacture with more environmental and cost-effective products (11). Another discovery that could change the future of rubber comes from farmers like Eric Mathur, a farmer based in the Phoenix desert. Mr. Mathur farms a plant called guayule. This plant can be identified by its chalky green leaves. A dissection of the plant reveals where its true potential lies. Behind the bark there is a thin layer of cells called parenchyma that can be used to manufacture rubber. Most importantly, this plant can be used to make the rubber that is used to manufacture vehicle tires. Whether it be a plane or a car, the contents of guayule–the parenchyma–can be used to outfit any vehicle with tires. A large problem in the U.S. is the dependence America has on Asia for rubber. If this plant could replace rubber, the U.S. could end the monopoly on the rubber trade and begin to harvest and possibly export homegrown rubber. However, the yield of rubber from the plant is low. This explains why mass planting of this plant has not occurred yet. Industrializing guayule would not be economically beneficial currently, but the future remains bright (9). Farmers are teaming up with scientists to rapidly produce new hybrids that are the outcome of crossbreeding. Crossbreeding only plants that have high rubber content results in a greater number of plants that will produce larger-than-normal amounts of rubber. Recent advancements place some of these plants at the same level as the natural rubber plant, making guayule a viable option (10). ConclusionRubber will always be a prominent material in our industry until a better alternative comes about. Synthetic rubber will continue to take over the marketplace due to its superior properties, mechanical performance, thermal stability, and compatibility with other petroleum products(2). The natural plant will still be utilized, but the synthetic option is likely the future. Nonetheless, since the discovery of rubber in 1845, it has been a crucial product across multiple industries. The advancement from naturally harvested rubber to a polished version of its synthetic counterpart is a significant milestone in American history. Cars have changed the way the world moves, and keeping those cars grounded and safe are tires constructed of this superplant. Without the discovery of rubber and its vulcanization, the world could still be rolling on wooden wheels. Not only in vehicles, but present in places like machines, medical devices, and construction, rubber has contributed to man significantly. Optimal versatility and compatibility make rubber a promising choice for professionals in countless fields, with more advancements being made constantly.