Characteristic
Polypropylene is referred to as PP, which is a colorless, odorless, non-toxic, translucent solid substance. Polypropylene is a thermoplastic synthetic resin with excellent properties, and is a colorless and translucent thermoplastic lightweight general-purpose plastic. With chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high wear-resistant processing properties, this has made polypropylene rapidly used in machinery, automobiles, electronics, construction, textiles, packaging since its inception. Agriculture, forestry, fishery and food industry have been widely developed and applied. In recent years, with the rapid development of my country's packaging, electronics, automobile and other industries, it has greatly promoted the development of my country's industry. And because of its plasticity, polypropylene materials are gradually replacing wooden products, and high strength, toughness and high wear resistance have gradually replaced the mechanical functions of metals. In addition, polypropylene has good grafting and compounding functions, and has huge application space in concrete, textile, packaging, agriculture, forestry and fishery.
Mice were intragastrically administered at a dose of 8g/kg for 1 to 5 times without causing obvious symptoms of poisoning. Rats inhaled the decomposition products of polypropylene heated to 210-220°C 30 times for 2 hours each time, and symptoms of ocular mucosa and upper respiratory tract irritation occurred. Same as polyethylene, it is prohibited to use its recycled products to hold food.
A brief history
In 1954, G. Natta first polymerized propylene into polypropylene (using aluminum-titanium chloride as a catalyst) and founded the theory of directional polymerization, which attracted people's attention.
In 1957, Montecatini in Italy and Hecules in the United States established polypropylene production plants with 6000t/a and 9000t/a respectively.
From the late 1960s to the mid-1970s, polypropylene entered a period of great development.
Since the 1980s, the output of polypropylene has been at the forefront of synthetic resins, and now it is only lower than polyethylene, ranking second.
China began to study the polypropylene production process in 1962. Since the 1980s, polypropylene has developed rapidly in China. my country has introduced some advanced technology and equipment for polypropylene production, and has successively established a number of large and medium-sized polypropylene production facilities in Yanshan, Yangzi, Liaoyang, etc., and a large number of small-scale bulk polypropylene production facilities have also been built in various places, and it is necessary to alleviate the contradiction between supply and demand. Played a certain role. The substantial increase in production scale has prompted my country's polypropylene resin production to enter a stage of rapid development. In 2012, my country's PP production capacity reached 12.967 million tons. In 2015, my country's PP production capacity was 21.3 million tons/year.
Supply and demand status
Due to the large gap between the supply and demand of polypropylene in my country, in recent years, most new large-scale oil refining, ethylene co-production projects and coal olefin projects have been equipped with polypropylene plants. Therefore, China's polypropylene production capacity will increase substantially in the future. At the same time, it is also necessary to consider those small and backward polypropylene installation technologies, especially intermittent small-body method devices, which will be phased out. It is estimated that by 2025, the production capacity of polypropylene in my country will reach a higher level. With the rapid development of China's economy, the increasing demand for various chemical raw materials has caused the consumption of polypropylene to reach the highest level ever. Therefore, my country will become the world's largest consumer of polypropylene. In 2003, the consumption of polypropylene in my country has reached 5.32 million tons; in 2007, it was the first to reach 10 million tons; affected by the financial crisis in 2008, it dropped slightly to 10.79 million tons; in 2018, driven by infrastructure investment and domestic demand, Increased to 12.32 million tons.
