As one of the pillar industries of light industry, the plastic industry has maintained a growth rate of more than 10% in recent years. While maintaining a rapid development speed, its economic benefits have also been improved. The total output value of enterprises above designated size in plastic products industry ranks third in light industry 19, and the product sales rate is 97.8%, which is higher than the average level of light industry.
From the production of synthetic resin, plastic machinery and plastic products, the development of plastic industry in China is strong. From June 5438 to February 65438, 2007, the total industrial output value of plastic products enterprises in China was 80 18 15657 thousand yuan, a year-on-year increase of 27.06%. From June 5438+0 to June 5438+0 in 2008, the total industrial output value of plastic products enterprises nationwide reached 788,006,448,000 yuan, up 22. 16% year-on-year.
2. What stages did the development of plastics go through? Since the birth of the first plastic product celluloid, the plastic industry has a history of 120 years.
Its development history can be divided into three stages. The processing stage of natural polymers is characterized by the modification and processing of natural polymers, mainly cellulose.
1869, American J. W. Hyatt found that adding camphor and a small amount of alcohol to nitrocellulose can make a plastic substance, which can be molded into plastic products under hot pressing, named celluloid. 1872 factory was built in Newark, USA.
At that time, it was not only used as a substitute for ivory, but also processed into windshields and movie films for carriages and cars, which created the plastic industry and developed the molding technology accordingly. 1903 A. Eichengreen, a German, invented nonflammable cellulose acetate and injection molding.
1905 Bayer of Germany conducts industrial production. During this period, some chemists synthesized a variety of polymers in the laboratory, such as phenolic resin, polymethyl methacrylate, polyvinyl chloride and so on. It laid the foundation for the development of plastic industry.
1904 The world plastic output is only 10kt, and there is no independent industrial department. The era of synthetic resin is characterized by the production of plastics based on synthetic resin.
From 65438 to 0909, American L.H. Baekeland made a breakthrough in the synthetic resin of phenol and formaldehyde, and obtained the patent right of the first thermosetting resin-phenolic resin. After adding filler into phenolic resin, it is made into molded products, laminates, coatings and adhesives by hot pressing.
This is the first fully synthetic plastic. 19 10 set up a general phenolic resin company in Lugus factory in Berlin for production.
Before the 1940s, phenolic plastic was the most important plastic variety, accounting for about 2/3 of the plastic output. Mainly used in electrical appliances, instruments, machinery and automobile industries.
After 1920, the plastic industry developed rapidly. The main reason is that German chemist Staudinger put forward the theory that polymer chains are composed of repeating units with the same structure through covalent bonds and the theory of cross-linking network structure of insoluble thermosetting resins, and American chemist W.H. carothers put forward the polycondensation theory in 1929, which laid the foundation for the development of polymer chemistry and plastic industry.
At the same time, due to the rapid development of the chemical industry at that time, a variety of polymerization monomers and other raw materials were provided for the plastic industry. Germany, with the most developed chemical industry at that time, was eager to get rid of the situation of relying heavily on natural products to meet various needs.
These factors strongly promote the development of synthetic resin preparation technology and processing industry. The first colorless resin is urea-formaldehyde resin.
1928 was put into industrial production by British melamine company. 19 1 1 year, F.E. Matthews of England made polystyrene, but there were some problems such as complicated process and aging of resin.
1930, German companies solved the above problems and industrialized production in ludwigshafen by bulk polymerization. In the research and production process of polystyrene modification, styrene resin based on styrene and copolymerized with other monomers was gradually formed, which expanded its application scope.
193 1 year, Roma-Haas company of the United States produced polymethyl methacrylate in bulk to make plexiglass. In 1926, W.L. Simon of the United States dissolved PVC powder which had not been found in use in a high-boiling solvent under heating, and unexpectedly obtained soft, easy-to-process and elastic plasticized PVC after cooling.
This accidental discovery opened the door to the industrial production of PVC. 193 1 year, our company produces emulsion PVC in the field.
194 1 year, the United States developed the technology of producing PVC by suspension method. Since then, PVC has been an important plastic variety and one of the main chlorine-consuming products, which has affected the production of chlor-alkali industry to some extent.
From 65438 to 0939, American melamine company began to produce molding powder, laminated products and coatings of melamine-formaldehyde resin. 1933, when the British chemical industry company carried out the experiment of the reaction of ethylene with benzaldehyde under high pressure, it was found that there were waxy solids on the wall of the polymerization kettle, thus polyethylene was invented.
1939 company uses high pressure gas phase bulk method to produce low density polyethylene. In 1953, K. Ziegler of the Federal Republic of Germany used alkyl aluminum and titanium tetrachloride as catalysts to make ethylene into high density polyethylene at low pressure. 1955, Hirst Company of the Federal Republic of Germany took the lead in industrialization.
Soon, the Italian G. Nata invented polypropylene, 1957, the first industrial production of Italian Monte Catini company. Since the mid-1940s, polyester, silicone, fluororesin, epoxy resin and polyurethane have been put into industrial production.
The total output of plastics in the world soared from 10kt in 1904 to 600 kt in 1944, and reached 3.4Mt in 1956. With the development of general plastics such as polyethylene, polyvinyl chloride and polystyrene, the raw materials are also changed from coal to petroleum, which not only ensures the full supply of polymer chemical raw materials, but also promotes the development of petrochemical industry, making raw materials available at multiple levels and creating higher economic value.
In the great development stage, the output of general plastics increased rapidly during this period. In 1970s, polyolefin plastics were put into production together with poly (1- butene) and poly (4- methyl-1- pentene). Formed the world's largest production series of polyolefin plastics.
At the same time, a variety of high-performance engineering plastics appeared. During the period of 1958- 1973 16, the plastic industry was in a period of rapid development, and the output of 1970 was 30Mt.
In addition to the rapid increase in output, its characteristics are: ① from a single large variety to a series of varieties through copolymerization or blending modification. For example, PVC not only produces many brands, but also develops chlorinated PVC, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer and impact-resistant PVC modified by blending or graft copolymerization.
② A series of new varieties of high-performance engineering plastics have been developed. Such as polyoxymethylene, polycarbonate, ABS resin, polyphenylene ether, polyimide, etc.
③ New technologies such as reinforcement, compounding and blending are widely adopted, which endows plastics with more excellent comprehensive properties and expands the application scope. During the period of 10 after 1973, the energy crisis affected the development speed of plastic industry.
At the end of 1970s, the total annual output of the world's major plastic varieties was: polyolefin 19Mt, PVC exceeded 100kt, polystyrene was close to 80kt, and the total plastic output was 63.6Mt 1982 began to recover.
Since 1983, the plastic industry has surpassed the highest level in history, with an output of 72Mt. Currently, plastics are used.
3. What stages did the development of plastics go through? Since the birth of the first plastic product celluloid, the plastic industry has a history of 120 years.
Its development history can be divided into three stages. The processing stage of natural polymers is characterized by the modification and processing of natural polymers, mainly cellulose.
1869, American J. W. Hyatt found that adding camphor and a small amount of alcohol to nitrocellulose can make a plastic substance, which can be molded into plastic products under hot pressing, named celluloid. 1872 factory was built in Newark, USA.
At that time, it was not only used as a substitute for ivory, but also processed into windshields and movie films for carriages and cars, which created the plastic industry and developed the molding technology accordingly. 1903 A. Eichengreen, a German, invented nonflammable cellulose acetate and injection molding.
1905 Bayer of Germany conducts industrial production. During this period, some chemists synthesized a variety of polymers in the laboratory, such as phenolic resin, polymethyl methacrylate, polyvinyl chloride and so on. It laid the foundation for the development of plastic industry.
1904 The world plastic output is only 10kt, and there is no independent industrial department. The era of synthetic resin is characterized by the production of plastics based on synthetic resin.
From 65438 to 0909, American L.H. Baekeland made a breakthrough in the synthetic resin of phenol and formaldehyde, and obtained the patent right of the first thermosetting resin-phenolic resin. After adding filler into phenolic resin, it is made into molded products, laminates, coatings and adhesives by hot pressing.
This is the first fully synthetic plastic. 19 10 set up a general phenolic resin company in Lugus factory in Berlin for production.
Before the 1940s, phenolic plastic was the most important plastic variety, accounting for about 2/3 of the plastic output. Mainly used in electrical appliances, instruments, machinery and automobile industries.
After 1920, the plastic industry developed rapidly. The main reason is that German chemist Staudinger put forward the theory that polymer chains are composed of repeating units with the same structure through covalent bonds and the theory of cross-linking network structure of insoluble thermosetting resins, and American chemist W.H. carothers put forward the polycondensation theory in 1929, which laid the foundation for the development of polymer chemistry and plastic industry.
At the same time, due to the rapid development of the chemical industry at that time, a variety of polymerization monomers and other raw materials were provided for the plastic industry. Germany, with the most developed chemical industry at that time, was eager to get rid of the situation of relying heavily on natural products to meet various needs.
These factors strongly promote the development of synthetic resin preparation technology and processing industry. The first colorless resin is urea-formaldehyde resin.
1928 was put into industrial production by British melamine company. 19 1 1 year, F.E. Matthews of England made polystyrene, but there were some problems such as complicated process and aging of resin.
1930, German companies solved the above problems and industrialized production in ludwigshafen by bulk polymerization. In the research and production process of polystyrene modification, styrene resin based on styrene and copolymerized with other monomers was gradually formed, which expanded its application scope.
193 1 year, Roma-Haas company of the United States produced polymethyl methacrylate in bulk to make plexiglass. In 1926, W.L. Simon of the United States dissolved PVC powder which had not been found in use in a high-boiling solvent under heating, and unexpectedly obtained soft, easy-to-process and elastic plasticized PVC after cooling.
This accidental discovery opened the door to the industrial production of PVC. 193 1 year, our company produces emulsion PVC in the field.
194 1 year, the United States developed the technology of producing PVC by suspension method. Since then, PVC has been an important plastic variety and one of the main chlorine-consuming products, which has affected the production of chlor-alkali industry to some extent.
From 65438 to 0939, American melamine company began to produce molding powder, laminated products and coatings of melamine-formaldehyde resin. 1933, when the British chemical industry company carried out the experiment of the reaction of ethylene with benzaldehyde under high pressure, it was found that there were waxy solids on the wall of the polymerization kettle, thus polyethylene was invented.
1939 company uses high pressure gas phase bulk method to produce low density polyethylene. In 1953, K. Ziegler of the Federal Republic of Germany used alkyl aluminum and titanium tetrachloride as catalysts to make ethylene into high density polyethylene at low pressure. 1955, Hirst Company of the Federal Republic of Germany took the lead in industrialization.
Soon, the Italian G. Nata invented polypropylene, 1957, the first industrial production of Italian Monte Catini company. Since the mid-1940s, polyester, silicone, fluororesin, epoxy resin and polyurethane have been put into industrial production.
The total output of plastics in the world soared from 10kt in 1904 to 600 kt in 1944, and reached 3.4Mt in 1956. With the development of general plastics such as polyethylene, polyvinyl chloride and polystyrene, the raw materials are also changed from coal to petroleum, which not only ensures the full supply of polymer chemical raw materials, but also promotes the development of petrochemical industry, making raw materials available at multiple levels and creating higher economic value.
In the great development stage, the output of general plastics increased rapidly during this period. In 1970s, polyolefin plastics were put into production together with poly (1- butene) and poly (4- methyl-1- pentene). Formed the world's largest production series of polyolefin plastics.
At the same time, a variety of high-performance engineering plastics appeared. During the period of 1958- 1973 16, the plastic industry was in a period of rapid development, and the output of 1970 was 30Mt.
In addition to the rapid increase in output, its characteristics are: ① from a single large variety to a series of varieties through copolymerization or blending modification. For example, PVC not only produces many brands, but also develops chlorinated PVC, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer and impact-resistant PVC modified by blending or graft copolymerization.
② A series of new varieties of high-performance engineering plastics have been developed. Such as polyoxymethylene, polycarbonate, ABS resin, polyphenylene ether, polyimide, etc.
③ New technologies such as reinforcement, compounding and blending are widely adopted, which endows plastics with more excellent comprehensive properties and expands the application scope. During the period of 10 after 1973, the energy crisis affected the development speed of plastic industry.
At the end of 1970s, the total annual output of the world's major plastic varieties was: polyolefin 19Mt, PVC exceeded 100kt, polystyrene was close to 80kt, and the total plastic output was 63.6Mt 1982 began to recover.
Since 1983, the plastic industry has surpassed the highest level in history, with an output of 72Mt. At present, plastic matrix composites.
Who knows the history of plastics? 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 troubles to the environment. People call the disaster that plastics bring to the environment "oil 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.
5. Molecular Discovery History of Plastic Industry Since the birth of the first plastic product celluloid, the plastic industry has a history of 120 years.
Its development history can be divided into three stages. The processing stage of natural polymers is characterized by the modification and processing of natural polymers, mainly cellulose.
1869 American J.W.
Hyatt found that adding camphor and a small amount of alcohol to nitrocellulose can make a plastic substance, which can be molded into plastic products under hot pressing, named celluloid. 1872 factory was built in Newark, USA.
At that time, it was not only used as a substitute for ivory, but also processed into windshields and movie films for carriages and cars, which created the plastic industry and developed the molding technology accordingly. 1903 german a.
Eichengreen invented nonflammable cellulose acetate and injection molding. 1905 Bayer of Germany conducts industrial production.
During this period, some chemists synthesized a variety of polymers in the laboratory, such as phenolic resin, polymethyl methacrylate, polyvinyl chloride and so on. It laid the foundation for the development of plastic industry. 1904 The world plastic output is only 10kt, and there is no independent industrial department.
The era of synthetic resin is characterized by the production of plastics based on synthetic resin. 1909 USA l
H Baekeland made a breakthrough in the synthesis of resin from phenol and formaldehyde, and obtained the patent right of the first thermosetting resin-phenolic resin.
After adding filler into phenolic resin, it is made into molded products, laminates, coatings and adhesives by hot pressing. This is the first fully synthetic plastic.
19 10 set up a general phenolic resin company in Lugus factory in Berlin for production. Before the 1940s, phenolic plastic was the most important plastic variety, accounting for about 2/3 of the plastic output.
Mainly used in electrical appliances, instruments, machinery and automobile industries. After 1920, the plastic industry developed rapidly.
The main reason is firstly the German chemist н. Staudinger put forward the theory that polymer chains are composed of repeating units with the same structure connected by covalent bonds and the theory of cross-linking network structure of insoluble thermosetting resins, 1929 American chemist w.
H carothers put forward the theory of polycondensation, which laid the foundation for the development of polymer chemistry and plastic industry.
At the same time, due to the rapid development of the chemical industry at that time, a variety of polymerization monomers and other raw materials were provided for the plastic industry. Germany, with the most developed chemical industry at that time, was eager to get rid of the situation of relying heavily on natural products to meet various needs.
These factors strongly promote the development of synthetic resin preparation technology and processing industry. The first colorless resin is urea-formaldehyde resin.
1928 was put into industrial production by British melamine company. 19 1 1 year, F.
E Matthews made polystyrene, but there are some problems, such as complex technology and aging resin.
1930, German companies solved the above problems and industrialized production in ludwigshafen by bulk polymerization. In the research and production process of polystyrene modification, styrene resin based on styrene and copolymerized with other monomers was gradually formed, which expanded its application scope.
193 1 year, Roma-Haas company of the United States produced polymethyl methacrylate in bulk to make plexiglass. The western United States, 1926.
L Simon dissolved PVC powder which had not been found in use in high boiling point solvent under heating, and after cooling, he unexpectedly obtained a soft, easy-to-process and elastic plasticized PVC.
This accidental discovery opened the door to the industrial production of PVC. 193 1 year, our company produces emulsion PVC in the field.
194 1 year, the United States developed the technology of producing PVC by suspension method. Since then, PVC has been an important plastic variety and one of the main chlorine-consuming products, which has affected the production of chlor-alkali industry to some extent.
From 65438 to 0939, American melamine company began to produce molding powder, laminated products and coatings of melamine-formaldehyde resin. 1933, when the British chemical industry company carried out the experiment of the reaction of ethylene with benzaldehyde under high pressure, it was found that there were waxy solids on the wall of the polymerization kettle, thus polyethylene was invented.
1939 company uses high pressure gas phase bulk method to produce low density polyethylene. 1953 k, Federal Republic of Germany
Ziegler used alkyl aluminum and titanium tetrachloride as catalysts to make ethylene into high-density polyethylene at low pressure, and Hearst Company of the Federal Republic of Germany took the lead in industrialization on 1955. Soon, Italy's g.
Nata invented polypropylene, and 1957 was the first industrial production of Italian Monte Catini company. Since the mid-1940s, polyester, silicone, fluororesin, epoxy resin and polyurethane have been put into industrial production.
The total output of plastics in the world soared from 10 kt in 1904 to 600 kt in 1944, reaching 3. 4 million tons.
With the development of general plastics such as polyethylene, polyvinyl chloride and polystyrene, the raw materials are also changed from coal to petroleum, which not only ensures the full supply of polymer chemical raw materials, but also promotes the development of petrochemical industry, making raw materials available at multiple levels and creating higher economic value. In the great development stage, the output of general plastics increased rapidly during this period. In 1970s, polyolefin plastics were put into production together with poly (1- butene) and poly (4- methyl-1- pentene).
Formed the world's largest production series of polyolefin plastics. At the same time, a variety of high-performance engineering plastics appeared.
During the period of 1958- 1973 16, the plastic industry was in a period of rapid development, and the output of 1970 was 30Mt. In addition to the rapid increase in output, its characteristics are: ① from a single large variety to a series of varieties through copolymerization or blending modification.
For example, PVC not only produces many brands, but also develops chlorinated PVC, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer and impact-resistant PVC modified by blending or graft copolymerization. ② A series of new varieties of high-performance engineering plastics have been developed.
Such as polyoxymethylene, polycarbonate, ABS resin, polyphenylene ether, polyimide, etc. ③ New technologies such as reinforcement, compounding and blending are widely adopted, which endows plastics with more excellent comprehensive properties and expands the application scope.
During the period of 10 after 1973, the energy crisis affected the development speed of plastic industry. At the end of 1970s, the total annual output of major plastics in the world was: polyolefin 19Mt, PVC exceeded 100kt, polystyrene approached 80kt, and the total plastic output was 63.
6 metric tons
6. The history of plastic development in China After a long struggle and opening to the outside world, the plastic industry in China has formed a relatively complete industrial system and become a basic material industry that keeps pace with steel, cement and wood. As a new material, its application field has far exceeded the above three materials. Since the 20th century, China plastics industry has made remarkable achievements and achieved a historic leap.
As one of the pillar industries of light industry, the plastic industry has maintained a growth rate of more than 10% in recent years. While maintaining a rapid development speed, its economic benefits have also been improved. The total output value of enterprises above designated size in plastic products industry ranks third in light industry 19, and the product sales rate is 97.8%, which is higher than the average level of light industry.
From the production of synthetic resin, plastic machinery and plastic products, the development of plastic industry in China is strong. From June 5438 to February 65438, 2007, the total industrial output value of plastic products enterprises in China was 80 18 15657 thousand yuan, a year-on-year increase of 27.06%. From June 5438+0 to June 5438+0 in 2008, the total industrial output value of plastic products enterprises nationwide reached 788,006,448,000 yuan, up 22. 16% year-on-year.
7. History of plastic industry: Since the birth of the first plastic product celluloid, the plastic industry has a history of 120 years. Its development history can be divided into three stages.
The processing stage of natural polymers is characterized by the modification and processing of natural polymers, mainly cellulose. 1869, American J. W. Hyatt found that adding camphor and a small amount of alcohol to nitrocellulose can make a plastic substance, which can be molded into plastic products under hot pressing, named celluloid. 1872 factory was built in Newark, USA. At that time, it was not only used as a substitute for ivory, but also processed into windshields and movie films for carriages and cars, which created the plastic industry and developed the molding technology accordingly.
1903 A. Eichengreen, a German, invented nonflammable cellulose acetate and injection molding. 1905 Bayer of Germany conducts industrial production. During this period, some chemists synthesized a variety of polymers in the laboratory, such as phenolic resin, polymethyl methacrylate, polyvinyl chloride and so on. It laid the foundation for the development of plastic industry. 1904 The world plastic output is only 10kt, and there is no independent industrial department.
The era of synthetic resin is characterized by the production of plastics based on synthetic resin. From 65438 to 0909, American L.H. Baekeland made a breakthrough in the synthetic resin of phenol and formaldehyde, and obtained the patent right of the first thermosetting resin-phenolic resin. After adding filler into phenolic resin, it is hot-pressed to make molded products.
8.8. What is the development history of HDPE? In this century, a revolutionary progress has taken place in the pipeline field, that is, "replacing steel with plastic".
With the rapid progress of science and technology of polymer materials, the continuous development and utilization of plastic pipes and the continuous improvement of production technology, the excellent performance of plastic pipes has been fully demonstrated. Nowadays, plastic pipes are no longer mistaken for "cheap substitutes" for metal pipes.
In this revolution, polyethylene pipes are favored and shine day by day. Widely used in gas transportation, water supply, sewage discharge, agricultural irrigation, mining, oil field, chemical industry, post and telecommunications and other fields of fine solid transportation, especially gas transportation. HDPE is a thermoplastic polyolefin produced by ethylene copolymerization.
Although 1956 introduced HDPE, this kind of plastic has not reached the mature level. This universal material is still developing new uses and markets.
The domestic producers of high-density polyethylene in China (excluding the high-density polyethylene produced by the full-density polyethylene factory) are PetroChina, Sinopec and CNOOC. By the end of 2006, there were four sets of high-density polyethylene plants under China Petroleum, namely Lanzhou Petrochemical High-density Polyethylene Plant, Daqing Petrochemical High-density Polyethylene Plant, Liaoyang Petrochemical High-density Polyethylene Plant and Jilin Petrochemical High-density Polyethylene Plant. High-density polyethylene is usually made by Ziegler-Natta polymerization, which is characterized by no branching in the molecular chain.