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polystyrene production​--英国论文代写范文精选

2015-12-26 | 来源:51Due教员组 | 类别:更多范文

51due英国论文代写网精选essay代写范文:  polystyrene production” ,这篇论文主要讲述了关于停止使用聚苯乙烯的一篇社会性essay范文,聚苯乙烯的高分子聚合物,通过缩聚反应合成苯乙烯单体的自由基。聚苯乙烯是一种无色,透明的热塑性塑料。在聚苯乙烯的整个发展过程中,我们发现,早在1839,德国第一次从天然树脂中提取聚苯乙烯。到1930年,德国的巴斯夫商业化生产聚苯乙烯。在1934年,美国陶氏在美国开始生产聚苯乙烯,并且在1954开始生产聚苯乙烯泡沫。由于聚苯乙烯容易成型,容易着色,防水防潮,轻便,所以它经常被用来制作泡沫产品。聚苯乙烯的也可以与其他类型的橡胶聚合物材料共聚生成具有不同力学性能的各种产品。在日常生活中一次性塑料餐具、透明的CD盒广泛应用。

1. Introduction

Polystyrene is the polymer that by the polycondensation reaction of the synthesis of styrene monomers by free radicals, it is referred to as PS. It is a colorless, transparent thermoplastic. Throughout the course of development of polystyrene, we found that as early as 1839, the German for the first time from a natural resin extracted polystyrene. By 1930, BASF in Germany commercial production of polystyrene. In 1934, Dow began production of polystyrene in the United States, and in 1954 began the production of polystyrene foam. Because polystyrene with easy to shape, easily colored, water-resistant moisture, lightweight and portable, so it is often used to make foam products. Polystyrene can also be other types of rubber polymer materials copolymer generate a variety of different mechanical properties of the product. Daily life of common applications in a variety of disposable plastic tableware, transparent CD box. Expanded polystyrene (Styrofoam) have a plenty of using as building materials since 2003, and it is widely used in making hollow floor noise insulation material.
     The World's polystyrene (PS) production capacity hit record highs due to the rapid growth of Asia production capacity of polystyrene (foam board) in the past 20 years, the production capacity has more than 13 million tons / year to the last century, all over the world in the same period. polystyrene consumption of only 10 million tons / year, accounting for only about 77% of the production capacity. The global polystyrene apparatus starts to remove the influence of various factors, the rate does not exceed 80%.The polystyrene of the world's total consumption in 2003 was 10.889 million tons, of which North American consumption of 2.505 million tons / year, accounting for 23.0% of the total consumption of the world polystyrene; South America's consumption of 445,000 tons / year, accounting for about 4.1% of the world's total consumption; Western Europe consumption of 2.269 million tons / year, accounting for 20.8% of the total consumption; Northeast Asia consumption of 4.092 million tons / year, accounting for consumption amount of 37.6%; Southeast Asia's consumption of 498,000 tons / year, accounting for 4.6% of the total consumption; other parts of the consumption of 1.08 million tons / year, accounting for 9.9% of the total consumption. Thus, North America, South America polystyrene production and marketing of basic balance, a slight surplus of Western Europe, Northeast Asia still need to rely on imports to meet the shortfall.
Use polystyrene bound to cause environmental pollution problems. Polystyrene can not be discarded into the biogeochemical cycles through biological decomposition and photolysis. Due to the low proportion of expanded polystyrene (Styrofoam) that float on the surface of the water or wind drift, resulting in subjective landscape damage. According to the survey of the California Coastal Commission (California Coastal Commission), polystyrene is a major marine flotsam. The marine life which eat this type of plastic will have its digestive system damaged.
       2. Polystyrene pollution of the environment
       Disposable plastic products because of its raw materials - polymer resin has a strong stability characteristics, it is difficult to have a degradation in the state of the natural environment, there can be hundreds of years, even thousands of years, so that a large number of a long time to accumulate, it will give the natural ecologyenvironmental damage.such kind ofdirect damage like these disposable plastic products mixed in the soil will affect the growth of crops, leading to reduced production of crops; or eating poultry, livestock, wild animals (and even endangered wildlife), will lead to their death. For example, Polystyrene plastic pollution trend of globalization, because of the tsunami in Japan, a large number of foam drifting across the Pacific Ocean, the weight of the polystyrene foam debris has been increased to 30% from 5% of the pre-tsunami. Because of its lightweight, so this is a huge number, a lot of wildlife in Alaska because of the incorrect eating these plastic and dead. By the metabolic activity of the animal, thetoxic substances will release into the environment[1].
       The damage to the environment in the process of dealing with disposable plastic products, such as the use of the landfill will continue to take up valuable land resources and produce large amounts of toxic and harmful gases such as incineration, destruction of the atmospheric environment; In addition, foamplastic food containers and packaging materials in the production process due to the use of HCFCs as a blowing agent will cause the a serious destabilizing effect in atmospheric ozone layer. In a new study, we found that, among the most toxic substances on Earth - remain high in the US food supply although they have declined in the environment. In most smelting industry in the production process, or in the bleached pulp and the manufacture of herbicides or pesticides, tend to produce dioxin-like by-products[3].
       Disposable plastic products which to be thrown away in the environment caused by people's visual dirty, messy feeling, these bubbles garbage with the thrust of the ocean, floating around, destroying the coastline, it destroys the urban, rural and landscapearea gives the landscape beauty, and even affect the mood of people's work and life, to bring a bad effect on the city's appearance and health and public health. According to the word of gulf of Alaska Keeper is preparing for next summer's cleanup. "It's a pretty amazing sight when you go out to the coast and see nothing but Styrofoam as far as you can see,"Plastic garbage bring bad effect on people's lives and need to be handled as soon as possible.
       3. To reduce the use of polystyrene
       We can develop new biodegradable plastic material technology, with the development of biotechnology, scientists continue to explore, there is now a seawater biodegradable plastic, non-toxic ingredients, and in a very short worldcan be dissolved. And the new plastic density of seawater, which would allow them to tend to sink instead of float, greatly reducing the pollution of the coastline. Based on the cruise liners, naval warships and other vessels generate huge volumes of plastic trash, such as stretch wrap for large cargo items, food containers and eating utensils. This junk often remains onboard for long spans of time until ships make port, the researcher Robson Storey, a polymer scientist at the University of Southern Mississippi thought we were moving toward making plastics more sustainable, especially those that are used at sea[4].There are huge space for development of Biodegradable materials. Future research also has to optimize the plastics for changes in temperature, humidity, seawater composition and other environmental conditions.
        Use the green tableware. Stainless steel cutlery nice, light and durable, popular with people of all ages, but if used improperly, trace elements in the stainless steel will slowly accumulate in the human body, a certain amount will be harmful to human health.Plastic tableware light and beautiful, not broken, cheap, ubiquitous in people's lives. The use of plastic tableware, temperature control is critical, different plastic tableware different temperature range, over a range of easy to produce toxic cyanide. Studies have found that about 30% of the dishes used at America's dinner table contain dangerous levels of lead and cadmium. Another study claims that when the ceramic is properly fired, these toxins will most likely not leach into the food. In light of several different cases of lead poisoning linked todinnerware, the National Safety Council advises: "Avoid eating off any colorfully painted ceramic plates, and avoid drinking from any ceramic mugs unless you know they do not leach lead. This is particularly important if the pottery was made in Mexico or another Latin America country, or in Asia. "Therefore, we can use the green tableware, such as Plates with Purpose by Riverside Design Group, Lauren Becker at Recycled Glassworks turns old glass into gorgeous dinnerware, Compostable, reusable plates by Verterra made completely from fallen leaves, all OccassionVeneerware by Bambu is certified organic, from organically cultivated bamboo and so on. Biodegradable tableware can replace use of polystyrene[5].
        Improve people's environmental awareness and social consciousness. Not only do we have to optimize the processing method of the polystyrene and improve polystyrene recycling efforts but also to strengthen the processing of white pollution, less use of plastic products, but also to raise people's awareness of environmental protection and social awareness through public advocacy, while speeding developed polypropylene an alternative to reduce the use of polypropylene in life, to build a comfortable, beautiful, livable, clean, healthy living environment, in line with the concept of sustainable development[2].
        Increasingly serious environmental pollution globalization has affected the survival and development of mankind, poses a serious challenge to the stability of the economic and social development, and involves the agriculture and food security, water security, energy security, ecological security, public health security.This is a global problem, not temporary, one place, one country will be able to independently solve, need everyone from the field of scientific, technical, economic, political, social, diplomatic and other efforts to protect our environment.In our lives, we can start from the little things. For example, we can choose to use the cardboard, but not use plastic bags, plastic boxes, etc. that made of polystyrene. This is because the tray sub easily recycled material can be a good microbial degradation of the environment not harmful, as compared with polystyrene, it is more secure, and will not cause a bad effect on the stored food.
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