Formula of degradable adhesive? The kind used to bind the broken powder and want to biodegrade itself.

White Pollution White pollution is a unique environmental pollution in China. A large number of discarded plastic products can be seen everywhere in various public places. They come from nature and are made by humans. When they finally belong to nature, they are not easily absorbed by nature, thus affecting the ecological environment of nature. From the perspective of resource conservation, since the main source of plastic products is exhausted oil resources, it should be recycled as much as possible. However, because the production cost of recycling at this stage is much higher than the direct production cost, it is difficult to do so under the current market economy conditions. Faced with the increasingly serious problem of white pollution, people hope to find a plastic substitute, which can not only replace the performance of existing plastics, but also cause no white pollution, and degradable plastics emerge as the times require. The characteristic of this new functional plastic is that its chemical structure will change obviously under certain environmental conditions after reaching a certain service life. For example, starch-filled plastics are rapidly decomposed by amylase secreted by microorganisms in the soil in a short time, which leads to the decline of mechanical properties of the film. At the same time, the self-oxidant added in the formula reacts with the metal salts in the soil to generate peroxide, which breaks the chain of polyethylene and degrades it into small fragments that are easily swallowed by microorganisms and absorbed by the natural environment. It can also improve the soil. The earth is our home, and this home is surrounded by garbage. As the masters of 2 1 century, we should not only worry and complain, but also act and act green. Garbage is not useless, nor is waste. Recycling garbage is not difficult in technology. The difficulty is that the garbage is thrown away casually and piled up together to become garbage. Therefore, as educated and civilized people in the new century, we should participate in the "easy-to-do" garbage source classification activities, contribute a little to purifying our living space, and offer a love. Domestic garbage is a by-product of human life. With the rapid development of social economy and the high concentration of urban population, the output of domestic waste is increasing gradually. Generally speaking, domestic waste can be divided into five categories: waste paper, plastic, glass, metal and biological waste. The harm of garbage to human life and environment mainly includes: First, it occupies too much land. Garbage piled up in the suburbs of the city occupies a lot of farmland. At present, the average annual output of garbage in Beijing is 440 kilograms, and the annual output of the whole city is about 4 million tons, which is equivalent to two semi-scenic mountains. There are more than 4,500 garbage dumps in Beijing. Orange peel for 2 years; Painted wooden board 13 years; Nylon fabric for 30-40 years; Leather for 50 years; 80- 100 cans; Plastics 100-200 years; Glass 1000. Therefore, we should not only make less garbage, but also pay attention to the classification and recycling of garbage, so as to turn waste into treasure. We should use less disposable chopsticks, cups, lunch boxes and other products, and use more reusable products to reduce the consumption of precious forest resources. Use less plastic bags and shopping bags to reduce the harm of "white pollution" in cities; Buy fluorine-free refrigerators, air conditioners and other environmental protection appliances to protect the atmospheric ozone layer; Use less high-concentration detergent and phosphorus-free washing powder to reduce water pollution. Second, pollute the air. Garbage is a complex mixture. In the process of transportation and open-air stacking, the decomposition of organic matter produces stench, which releases a lot of pollutants such as ammonia and sulfide into the atmosphere, including more than one kind of organic volatile gas 100. These releases contain many carcinogens and teratogens. Plastic film, paper scraps and dust fly with the wind, forming "white pollution". Third, the water body is polluted. Harmful components in garbage are easily washed into the surface water by rainwater, and a large number of acidic and alkaline organic pollutants are also produced during garbage stacking or pit filling, and heavy metals in garbage are dissolved. The exudate produced by garbage pollution sources will penetrate into groundwater through soil. If garbage is directly dumped into rivers, lakes or oceans, it will cause more serious pollution. You see: plastic bottles and lunch boxes floating on the surface of the Summer Palace and Beihai, plastic bags and bread paper hanging on the branches scattered on the mountain roads of Xiangshan and Badachu forests. Some tourists only care about their own convenience, which will pollute the tourist environment. If animals eat white garbage by mistake, it will not only harm health, but even lead to death. Fourth, the soil will become muddy. Garbage will be directly used for farmland. Or simply used in farmland, it will destroy the aggregate structure, physical and chemical properties and water and fertilizer conservation ability of soil. In particular, if plastic bags and plastic sheets are buried in farmland, the roots of crops will not grow, the yield of farmland will be reduced, and the food available for people will be reduced. Fifth, fire hazards. Garbage contains a lot of combustible substances, and methane and other combustible gases will be produced during natural stacking. In case of open fire or spontaneous combustion, it is easy to cause fire. With the increase of organic matter content in municipal waste and the change from scattered stacking in the open air to centralized stacking, the harm of biogas produced by long-term stacking of waste is becoming increasingly prominent, and garbage explosion accidents continue to occur, resulting in heavy losses. Sixth, the nest of pests. Garbage not only contains pathogenic microorganisms, but also provides places for mice, birds and mosquitoes and flies to eat, live and reproduce. It is also the source of infectious diseases. In a word, the seriousness and urgency of urban garbage problem is obvious. To turn this rubbish into treasure, we must recycle it. Do you know that?/You know what? Recycling 1 ton of waste paper can produce 800 kilograms of good paper, and cutting down less 17 trees can save more than half of paper-making energy and reduce 35% of water pollution. 1 ton of waste plastics can recover at least 600kg of gasoline and diesel; Using waste glass to rebuild glass can not only save quartz sand, soda ash and other raw materials, but also save electricity; Smelting metal with scrap metal can save a lot of energy consumption and reduce air pollution; Some kitchen waste, such as skins, eggshells, vegetable leaves and leftovers, can be composted and fermented to become green fertilizers. Therefore, through various mass media such as television, radio, newspapers and information networks, we should vigorously carry out publicity and education on classified collection of garbage sources; Pay close attention to the formulation of laws and regulations on the classified collection and treatment of garbage suitable for the national conditions, and strictly implement them; It can be considered to carry out the pilot work of classified collection of garbage sources in some units in depth and in detail; And further discuss with you to improve the management methods, so that the classified collection of source garbage can be widely carried out as soon as possible. Let's work together to promote the classified collection of garbage, eliminate garbage pollution, turn waste into treasure, save resources, make Beijing win the right to host the 2008 Olympic Games with a brand-new look, and provide ourselves with a beautiful and healthy living space. Plastic products are light, waterproof and corrosion-resistant new materials. It is widely used all over the world. Plastics were first used in agricultural plastic films, which brought great development to agricultural production, enabled crops to grow in any season and promoted market consumption. According to market statistics, from 1990 to 1995, the output of plastics increased at an annual rate of 8.9%, which has swept the whole earth. It can be called the "white revolution". But it's in progress. It also brought "white disaster" to people. Today, "white pollution" has become a well-known new term. Mainly refers to all kinds of foamed plastic bags and agricultural plastic films that pollute the environment and cause widespread concern in society. Taiwan Province Province of China issued a ban on "white products" on 1994, and one year later, the order was cancelled. As early as 65438, Hangzhou City. Local use of disposable foamed plastic tableware is prohibited. Guangzhou issued a government order on June 1997, stipulating that the production, sale and use of disposable non-degradable plastic lunch boxes are prohibited in the whole city from September 1 day of that year. Based on this, the State Economic and Trade Commission issued Order No.6 in June 1999, which made it clear that disposable foamed plastic tableware should be completely eliminated before the end of 2000, and the production, sale and use should be completely banned from 200 1. It can be seen from the above materials that more than a year has passed since the deadline, but disposable foamed tableware can still be seen everywhere, and the government has also changed from the "white ban" at that time to "ambiguity", often perfunctory, and the "white ban" has become a dead letter. We have carried out various investigations and studies, consulted various materials, and obtained all aspects of various new substitutes developed and put on the market in China so far, and analyzed and summarized them. Difficult course? We went to Xigu District Environmental Protection Bureau and received a warm reception. During the conversation, we realized the true composition of "white pollution", got a preliminary understanding of the concept of "white pollution" and got some understanding of the current plan to control "white pollution" (prepared a question and answer record). We went to Xinhua Bookstore, provincial library and school stacks, but there was little information about "white pollution", only the components of polyethylene, polypropylene and polyvinyl chloride, which hindered the research process. In order to get rid of the predicament, we decided to use today's information technology-surfing the Internet. We found a vast space on the Internet, which gave us a deeper understanding of "white pollution" and helped us to write a paper. With the above foundation, we decided to deeply understand the "white pollution" in Lanzhou. We interviewed Hualian Supermarket, Electric Supermarket, and some retail stores and vendors. We are deeply shocked. There are so many plastic belts every day that foam lunch boxes is thrown away at will, but people turn a blind eye to them. We feel that if the quality of residents is not improved, the problem of "white pollution" should be solved. It's really hard. (There is a questionnaire available) "White pollution" has such a strong vitality, what kind of serious harm will it bring to our lives, and the following contents will be described. First, let's learn about the composition of plastic. First, the composition of "white pollution" mainly refers to white foamed plastic lunch boxes and various plastic bags. Agricultural plastic film has caused pollution to the environment, but "white pollution" is not what people usually think of as plastic products. As we all know, plastic is a new material with excellent comprehensive performance and a consumer product. Generally speaking, it is also a substance. Any substance has its life cycle, and the whole process of reaching the end of the life cycle is a degradation process. So the plastic itself is degradable. Only through stabilization technology. That is to say, light stabilizer, heat stabilizer and antioxidant are added to delay or inhibit its inherent biodegradability. And there are more than 300 kinds of plastics, and there are more than 40 kinds in common use. In fact, only a small part of it can become white pollution. So "white pollution" cannot be equated with plastic. The main components of "white pollution" are polyethylene (PE), polyvinyl chloride (PV), polypropylene (PP) and polystyrene resin (PS). We made polyethylene one by one: polyethylene is a thermoplastic resin, which is formed by addition polymerization of ethylene. According to the polymerization conditions, polyethylene with relative molecular weight ranging from tens of millions can be obtained. Polyethylene is white particles or powder, translucent, non-toxic, tasteless, good chemical stability, acid and alkali corrosion resistance. Commercially, polyethylene is divided into low density, medium density and high density. Generally, low-density polypropylene (0.92g/cm3-0.93g/cm3) without plasticizer is used for packaging: the relative molecular weight is between 800,000 and 200,000. Polypropylene skeleton. If methyl groups are regularly distributed on both sides of the main chain, it is called syndiotactic polypropylene; If methyl groups are randomly distributed in the main chain, it is called random polypropylene. Polypropylene is usually a translucent solid, odorless and nontoxic, with a density of (0.90 g/cm3-0.9 1g/cm3), which has higher mechanical strength and better heat resistance than polyethylene. Among the three kinds of polypropylene, isotactic polypropylene has the largest output. Titanium trichloride-diethyl aluminum chloride is used as a catalyst for polymerization of propylene in saturated gasoline. Isotactic polypropylene (PP) and polyvinyl chloride (PVC) were obtained. The relative molecular weight is 50000-65438+200000. PVC is a thermoplastic resin obtained by free radical addition polymerization. It is an amorphous white powder with a density of (65,438+0.35g/cm3-65,438+0.45g/cm3) and has good chemical stability. It is melted in cyclic ethyl ketone. Toluene-acetone mixed solvent, etc. Polystyrene: The average relative molecular weight is about 200,000. It is a colorless and odorless transparent resin with good light transmittance. Its surface is shiny and flammable, and its density is (1.05g/cm3-1.07g/cm3). It has excellent water resistance, corrosion resistance and electrical insulation. Production methods: bulk polymerization and suspension polymerization. Emulsion polymerization. This paper introduces the ontology polymerization method. Initiator and a small amount of additives were added to styrene monomer, and then low-temperature polymerization was carried out in a prepolymerization kettle to prepare prepolymer, which was then transferred to a polymerization tower for high-temperature heating and kept at a certain temperature in stages. After the reaction, the molten polystyrene is extruded into strips, cooled and hardened in water, and cut and packaged. These are the main components of "white pollution". In addition, plasticizers, foaming agents and packaging are added to these pollutants. Plastic garbage has not been properly managed and treated, garbage has not been collected separately, and what can be recycled has not been recycled. The final disposal method of garbage basically stays at the level of bare stacking or shallow burial, and some towns regard rivers, lakes and seas as natural garbage dumps. Transportation and tourism, except railways, have not yet established a garbage collection system suitable for production and operation, and let the garbage generated in the course of operation drift. Weak management? Lack of relevant laws and regulations on plastic packaging waste, people's environmental awareness is relatively weak; Abuse and random dumping are quite common, and this is not the responsibility of plastic products themselves. 2. Main hazards: "White pollution" mainly refers to two negative impacts on the environment: "visual pollution" and "potential hazards". "Visual pollution" refers to dispersion in cities. The plastic rubbish discarded by people has damaged the city appearance and landscape. For example, a large number of polystyrene foamed plastic tableware scattered on both sides of railways, rivers and lakes, and ultra-thin plastic bags flying all over the sky or hanging on branches all bring bad visual stimulation to people, and people react strongly to it. The "potential crisis" refers to the environmental problems caused by the difficulty of degradation of plastic waste after it enters the natural environment. Its harm mainly includes the following points: it is not easy to recycle, because the recycling cost is high, but the utilization rate is low, so the business can be said to be unprofitable, and the recycling price is low, which makes it difficult to attract the general public to carry out "white recycling". So it is not easy to recycle. It is difficult to degrade. The recovered white waste is not easy to treat. At present, the main treatment methods are incineration and landfill. If burned, it will produce a lot of toxic smoke, pollute the atmosphere and promote the formation of acid rain. As for landfill, it will remain unchanged for 100 years and will not be absorbed by nature, which will do great harm to the land, change its pH value, affect the absorption of nutrients and water by crops, and lead to agricultural production reduction. As for plastic products discarded in water or land, it not only affects the environment, but also leads to death if swallowed passively, thus destroying the ecological balance. Toxic substances decompose at high temperature, and plastic products themselves have no toxic substances. However, due to their imperfect recycling equipment and simple process, many manufacturers do not have legal business licenses. When the temperature of recycled plastic products reaches 65℃, toxic substances will precipitate and penetrate into food. It will cause harm to important parts of the human body such as liver, kidney, reproductive system and central nervous system. Third, the reason why "white pollution" has a broad market lies in the related problems existing in the process of governance. Earlier, we mentioned the document of the Economic and Trade Commission, which clearly pointed out that "all foam plastics will be eliminated by the end of 2000". Today, foam still exists, why does it still have such a strong vitality! The reasons are as follows: the finished products made of degradable materials are immature. Because of the complex manufacturing process, its price is 1 ~ 2 times higher than that of "white products", and people are certainly reluctant to "give up the chaff and get expensive". On the other hand, the performance of finished products made of degradable materials is not as good as that of "white products", because the production technology of "white products" is mature after years of experience, and new materials have just been developed, and some of them have already existed. The crackdown is not strong enough. At present, restaurants sell "white products", which are widely used, openly and blatantly in market transactions, and turn a blind eye to state regulations, making the "white ban" work in recent years a "white ban". The quality of citizens needs to be improved. The quality of a citizen reflects the national quality of a country, but people's awareness of environmental protection is still very weak, and the habit of littering is still very common. This phenomenon will bring great harm to our natural environment, and its appearance will bring great problems to the recovery of "white waste". The facilities for recycling "white pollution" are not complete. As mentioned earlier, the low recycling rate of "white pollution" is mainly due to the backward technology and insufficient capital investment in China, so some new products that have been developed in China cannot be put into production. Manufacturers have changed from "open" to "semi-open". With the introduction of the national "white goods ban" policy, the manufacturers of "white goods" have also shifted from urban production to rural and suburban areas, and from open-air production to semi-open-air production. Because of the poor conditions, the manufactured goods are unqualified, which brings difficulties to the government's "white goods ban". From the above examples, we can see that at present, there are two main ways to solve "white pollution": recycling waste plastics and biodegradable plastics. Answer: recycling waste plastics (that is, recycling waste plastics as resources, developing and utilizing them). ) (1) are directly used as materials, and some recycled plastic products can be recycled and processed to make new plastic products. (2) manufacturing a synthetic polymer unit. Polymers are made of. Then under certain conditions, waste plastics can be made into monomers, such as polyester plastics, by alcoholysis. (3) It can be made into fuel oil. Polymer chains such as polyethylene and polypropylene can be decomposed into low molecular petroleum hydrocarbons at high temperature, and then fractionated to obtain various fuel oils. Biodegradable plastics. (1) natural polymer conversion method. That is, starch, cellulose, chitin, lignin and seaweed are used. Through chemical modification and * * * polymerization, these molecules are modified to synthesize biodegradable plastics. (2) Chemical synthesis method is used to simulate the structure of natural polymers. Starting from simple water molecules, active groups such as amide groups, peptide groups and ester groups are attached to the polymer chain of plastics. The compounds containing these groups are similar to natural protein, and the structural fragments of oil are easy to biodegrade. (3) Microbial fermentation, in which many microorganisms can secrete polyester and polysaccharide polymers by taking some organic substances as carbon sources. These molecules are easily degraded and can be further recovered. However, some plastics are not suitable for recycling because of the different structures of materials and some special additives. There are also some plastic fragments that degrade slowly in the natural environment and cannot completely solve the "potential harm" to the environment. Therefore, on the one hand, while controlling "white pollution", on the other hand, we should actively prevent the emergence of new "white pollution" sources. Therefore, China's environmental protection department put forward that the prevention and control of white pollution should be "publicity and education as the leading factor, strengthening management as the core, and recycling as the main means." Of course, "white pollution" is a worldwide problem, and due to limited development, we can't study it in depth. All we can do now is collect and sort out the data. But by studying this problem, we can also have a general understanding of "white pollution". Although we have learned about the governance and solutions of "white pollution" in today's world, we still can't completely solve it. Our touching low quality does serious harm to the environment. Only improving people's awareness of environmental protection is the most feasible way to solve "white pollution".