English composition on plastic bag (word 100~ 120)

A photographer's experiment in a darkroom led to the first plastic. Alexander Parks has many hobbies, and photography is one of them. In the19th century, people can't buy ready-made photographic films and chemicals as they do today. They must always make what they need. So every photographer must also be a chemist.

One of the materials used in photography is "collodion", which is a kind of "nitrocellulose" solution, that is, nitrocellulose solution in alcohol and ether. At that time, it was used to stick photosensitive chemicals on glass and make photographic film equivalent to today.

In the 1950s of 19, Parks studied different methods to treat collodion. One day, he tried to mix collodion with camphor. To his surprise, a flexible hard material was produced after mixing. Parks called this substance "Paxsin", which was the earliest plastic.

Parks made all kinds of objects with Paxsin: combs, pens, buttons and jewelry patterns. However, Parks is not very business-conscious. He lost money in his business venture. In the 20th century, people began to explore new uses of plastics. Almost everything in the house can be made of some kind of plastic.

Leave it to other inventors to continue to develop Parks' achievements and profit from them. John wesley Heath, a printer from New York State, saw this opportunity in 1868, when a billiards company complained about the shortage of ivory. Heath improved the manufacturing process and gave Paxsin a new name-celluloid. He got a ready-made market from billiards manufacturers, and soon he made various products out of plastic.

Early plastic caught fire easily, which limited the range of products made from it. The first plastic that can successfully resist high temperature is "Beckett". Leo Baekeland obtained this patent on 1909.

1909, phenolic plastics were synthesized for the first time in Baekeland, USA. In 1930s, nylon came out again, which was called "a kind of fiber composed of coal, air and water, thinner than spider silk, harder than steel and better than silk". Their appearance laid the foundation for the invention and production of various plastics. Due to the development of petrochemical industry in World War II, the raw material of plastics replaced coal with oil, and the plastic manufacturing industry also developed rapidly.

Plastic is a very light substance, which can be softened by heating at a very low temperature and made into various shapes at will. Plastic products are bright in color, light in weight, not afraid of falling, economical and durable. Its appearance not only brings a lot of convenience to people's lives, but also greatly promotes the development of industry.

However, plastics were invented less than 100 years ago. If people were ecstatic about their birth at that time, now they have to deal with these things that are full of life and pose a great threat to the living environment of mankind.

Plastic is a chemical petroleum product extracted from petroleum or coal, and it is difficult to degrade naturally once it is produced. Plastics will not rot and degrade after 200 years underground, and a large amount of plastic garbage will destroy the permeability of soil, harden the soil and affect the growth of plants. If domestic animals eat plastic mixed with feed or left in the wild by mistake, they will also die because of digestive tract obstruction.

At present, the annual output of plastics in China is 300,000 tons and the consumption is more than 6 million tons. The annual output of plastics in the world is 654.38 billion tons. If the annual plastic waste is calculated as 654.38+05%, the annual plastic waste in the world is 6.5438+05 million tons, and the annual plastic waste in China is more than 6.5438+00 million tons, accounting for 40% of the waste. So a lot of waste plastics are buried underground as garbage, which undoubtedly gives the already scarce cultivated land.

Plastics not only bring convenience to people's lives, but also bring irreparable trouble to the environment. People call the disaster that plastics bring to the environment "white pollution".

At present, many countries use incineration (heat energy recovery) or reprocessing (product recovery) to treat waste plastics. These two methods can recycle waste plastics and save resources. However, because waste plastics will produce gases harmful to human body and pollute the environment when they are burned or reprocessed, it can be said that the treatment of waste plastics is still a headache in environmental protection work.

The history of plastic bags

Experiments in darkroom led to the creation of the original plastic photographer. Alexander Parks has many hobbies, and movies are one of them. People can't buy ready-made films and chemicals like today, so they have to make what they often need in the19th century. So every photographer must also be a chemist. One of the materials used in movies is "collodion", which is a kind of "saltpeter cotton" solution, namely. It exists in the ethanol and ether solution of nitrocellulose. At that time, it was glued to the glass with photosensitive chemicals, and today it is made into something similar to photographic film. In11950s, Parks tested the methods to deal with the diversity of collodion. One day, he was trying to mix collodion with camphor. Using his magic, mixing produced a flexible hard material. Pax called that substance "Pax Hin", which was the earliest plastic. Parks made all kinds of articles with Paxshin: combs, pens, buttons and jewelry seals. Pax doesn't have a strong sense of business, but he has already suffered losses in venture capital. In the 20th century, people began to explore new uses of plastics. Almost all items made of some kind of plastic for domestic use can be taken out. Continue to develop Parks' achievements and profit from them, leaving it to the inventors to create others. John wesley Heath is a reporter from new york, so he saw this opportunity on 65438+ 0868, when a table tennis company complained about the shortage of ivory. Heath improved the production process, and gave a new name "celluloid" to Paxsin (such as ivory translation). He got a ready-made market from table tennis manufacturers, and soon after that, he made various products out of plastic. T-shaped plastic is easy to catch fire, and now it has limited the scope of products made from it. The first successful high-temperature resistant plastic was "Beckett" (phenol is short for plastic). Leo Baekeland has obtained this patent on 1909.

1909, phenolic plastics were first synthesized in Baekeland, USA. /kloc-in the 1930 s, nylon came out, which was called "thinner than the fiber yarn composed of coal, air and water, harder than steel, and denser than spider webs". After the invention of various plastics and the emergence of their production for this purpose laid the foundation. Petroleum has replaced coal as the raw material of plastics, and since the Second World War, the plastic manufacturing industry has also been impacted by the development of petrochemical industry and developed rapidly. Plastic is a very light substance, so heating at a very low temperature may deliquesce it and make it into various shapes at will. Plastic products are bright in color, not afraid of light weight, economical and durable. Its appearance not only brings a lot of convenience to people's lives, but also greatly promotes the development of industry. However, the invention of plastics is less than 100 years, and people have no choice but to deal with these things that pose a great threat to the living environment of human beings, but now people are rejoicing in their appearance. Plastic is a chemical polyester product extracted from petroleum or coal, which is difficult to degrade naturally once it is produced. In the past 200 years, the deterioration of plastics in the ground is also not good. A large amount of plastics buried in garbage will destroy the soil properties, harden the soil and affect the growth of plants. If cows eat the plastic mixed in feed or left in the wild by mistake, they will also die because of digestive tract obstruction.

At present, the annual output of plastics in China is 30,000 tons O0, and the consumption is over 6 million tons. The annual output of plastics in the world is1000000 tons. According to the annual plastic waste of 15%, the annual plastic waste in the world is 150000 tons, and the annual plastic waste in China is above100000 tons, accounting for 40% of the waste plastic waste. Such a large number of waste plastics are buried as garbage. It has brought greater pressure to the land that is already under great pressure, and the shortage of plastic in cultivated land not only brings convenience to people's lives, but also brings intractable future troubles to the environment. People call the disaster brought by plastic to the environment "white pollution". At present, many countries adopt (regeneration of combustion heat source) or processing and manufacturing (regeneration of products) to treat waste plastics. These two ways make waste plastics recycled and achieve the purpose of saving resources. Because waste plastics will produce harmful gases and pollute the environment when they are burned or treated again, it can be said that the treatment of waste plastics is still an environmental problem but a headache in work.