As a new material in industrial products, plastic industry has a history of 120 years since the birth of the first plastic product celluloid. In this 120 years, the functionalization of plastics has been brought to the extreme. It has brought us countless conveniences, but it has also caused serious pollution. 2 1 There should be new innovations and breakthroughs in plastic materials in the world! Let's talk about the development of plastics.
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 connected by valence 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 polymerized 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. 1953, K. Ziegler of the Federal Republic of Germany used alkyl aluminum and titanium tetrachloride as catalysts to make ethylene into high-density polyethylene under low pressure. 1955, Herst 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 600kt 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 as follows: ① from a single large variety through * * * polymerization or * * * mixed modification, it has developed into a series of varieties. For example, PVC not only produces various brands, but also develops chlorinated PVC, vinyl chloride-vinyl acetate polymer, vinyl chloride-vinylidene chloride polymer, and * * * mixed or grafted impact-resistant PVC. ② Developed a series of high-performance engineering plastics such as polyformaldehyde, polycarbonate, ABS resin, polyphenylene ether and polyimide. ③ New technologies such as reinforcement, compounding and * * * mixing 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, the world output of synthetic materials with plastics as the main body has exceeded the output of all metals.
Development of China Plastics Industry 192 1 year, Shanghai Shengde Saizhen Factory (now Shengde Plastics Factory) began to produce celluloid products, and later established Jianhua, Yonghe, Guoguang and Zhongxing factories. 1926, Shanghai Shengde Saizhen Factory began to produce phenolic resin and molding powder (phenolic molding compound). From 65438 to 0949, the output of plastics in China was about 400 tons. After the founding of the People's Republic of China, thermosetting plastics such as phenolic plastics have developed. 1958 The first set of PVC production equipment with an annual output of 3kt was completed and put into operation in Jinxi Chemical Plant, marking a new era for China's plastic industry. 1960 A polystyrene production plant with an annual output of 500t was built in Shanghai. 1965 Gao Qiao chemical plant produces kiloton high density polyethylene; 1970 Lanzhou chemical company's 3.5kt/a high-pressure polyethylene plant and 5kt/a polypropylene plant were put into production. The total plastic output of 1965 is 97kt. 1970 increased to 176kt. After the 1970s, the synthetic resin production facilities of several large petrochemical enterprises, such as Beijing Yanshan Petrochemical Company, Liaoyang Petrochemical Fiber Company and Shanghai Petrochemical General Factory, were put into production one after another. 1982 The annual output of synthetic resin exceeded one million tons.
Now plastics are constantly developing and progressing. Plastics are used in countless fields. This paper mainly talks about several newly expanded application fields. From now until 20 15, China's plastic raw material resin will grow rapidly and several world-class large-scale ethylene projects will be expanded. In the 11th Five-Year Plan, the total amount of ethylene will reach about 8.5 million tons, and the synthetic resin will increase substantially, providing a raw material base for the development of plastic products industry. In terms of per capita consumption, the per capita consumption in China is only about 12kg, while that in developed countries is 30k g ~ 100kg, and the average consumption in the world also reaches 18kg. Therefore, the development prospect of China plastics industry is very broad. 10 years, the application field of plastic products in the world has been expanding. In the next 10 year, the world's plastic products will increase at an annual rate of 3%, and by 20 10 year, the total output of plastic products in the world will reach 654.38+86 million tons.
The future development of plastic industry in China will mainly be in agricultural plastic products, agricultural plastic water-saving equipment, packaging plastic products, building plastic products, industrial transportation and engineering plastic products. Agricultural water-saving and energy-saving agent packaging plastic products are as follows:
Agricultural plastic products
According to the incomplete statistics of the Agricultural Film Professional Committee of China Plastics Association, there are nearly 1,000 agricultural film production enterprises of different scales in the whole industry, with the production capacity exceeding 2 million tons/year and the actual output exceeding 6,543.8+0,000 tons/year, of which about 60 enterprises have the annual production capacity exceeding 1 10,000 tons. There are about 30 large-scale backbone enterprises, with production capacity and annual output accounting for 60% of the country. China has become the country with the largest output and usage of agricultural film in the world. According to the statistics of the Ministry of Agriculture, in 2005, the cultivated area of horticultural facilities in China reached about 23 million mu, and the national plastic film coverage area reached 65.438+0.7 billion mu. Together with ammoniated film, silage film and feed packaging film, plastic seedling containers, sunshade nets, insect-proof fields, fishing nets, agricultural products storage and fresh-keeping materials, pesticide equipment and foam plastic plates, about 3 million tons of plastic products are needed every year.
Agricultural plastic water-saving equipment
According to the preliminary planning of the water conservancy department, the area of water-saving irrigation project should reach 65.438+0.4 billion mu on the basis of the current 250 million mu, reaching 400 million mu in total. Among them, there are 79 million mu of sprinkler irrigation, 6.5438+million mu of drip irrigation, 6.5438+0.4 million mu of pipeline water delivery and 50 million mu of canal seepage prevention, which require 6.5438+0.7 million tons/year of various plastic water-saving devices such as pipe fittings, emitters, impervious membranes and geotextiles.
Energy saving benefits of plastic products
Plastic building materials can not only replace steel and wood in large quantities, but also have the advantages of saving energy and materials, protecting ecology, improving living environment, improving building function and quality, reducing building self-weight and convenient construction.
The energy-saving benefit of plastics is very prominent, and its energy-saving benefit is manifested in two aspects: saving production energy consumption and using energy consumption. In terms of production energy consumption, the production energy consumption of plastic products is only 1/4 and 1/8 of steel and aluminum, the production energy consumption of rigid PVC plastics is only 30%~50% of that of cast iron pipes and steel pipes, and the production energy consumption of plastic water supply pipes can be reduced by about 50% compared with that of metal pipes.
Packaging plastic products
Packaging is still the largest application field of plastics, and its development still greatly exceeds other traditional packaging materials. The output of cement and fertilizer in China ranks first in the world. At present, more than 50% of cement packaging uses composite woven bags, as well as mineral products, chemical products synthetic resin, raw salt, sugar, cotton and wool. Due to the lack of paper and jute resources in China, it is an inevitable trend to use plastic packaging as the main packaging material.
China is a big grain producer with an annual output of nearly 500 million tons, which requires a lot of packaging materials. Small grain packaging in China has started in some big cities and made progress. If the proportion of grain sold in small packages in China reaches the level of developed countries, at least 165438+ 10,000 tons/year of various plastic substrates are needed.
Food, beverages, medicines, washing products, cosmetics and chemical products have developed rapidly in China. They have a great demand for packaging products such as composite films, packaging films, containers, turnover boxes and plastic trays. For example, the output of beverages will basically double in five years, and it is expected to reach about 30 million tons by 20 10, of which 50% will use polyester bottles, that is, 65438. There are also instant food, dairy products, canned food, food, monosodium glutamate, candy, biscuits and other packaging materials that need millions of tons. There is also a big market for pharmaceutical packaging. To sum up, the total demand for packaging materials products is about 5.5 million tons/year.