Polyolefins

Polyolefins are polymers that are produced from alkenes such as ethylene , propylene , 1-butene or isobutene by chain polymerization . The polyolefins are saturated hydrocarbons , which represent the largest group of plastics in terms of quantity . They are semi-crystalline thermoplastics that are easy to process. They are characterized by good chemical resistance and electrical insulating properties.

With 11.2 million tons, polyolefins represent around 47% of the total annual European consumption of plastic of 24.1 million tons.

raw materials

The raw materials ethene, propene and the C4-olefins come mainly from petrochemical steam cracker processes . Renewable raw materials such as ethanol from sugar cane represent another regional source of ethene through dehydration.

Alpha-olefins such as 1-hexene come from the SHOP process through the oligomerization of ethene.

Manufacturing

World's largest manufacturer of polyolefins (as of 2006)

rank	Companies	country	Annual production in million tons, rounded
1	ExxonMobil	United States	9.2
2	Dow Chemical	United States	8.3
3	LyondellBasell	Netherlands	7.8
4th	Ineos	Great Britain	5.5
5	Sinopec	China	5.2
6th	Sabic	Saudi Arabia	5.1
7th	Borealis	Austria	4.2
8th	Total	France	4.1
9	Chevron Phillips	United States	3.2
10	Petrochina	China	2.5
11	Equistar	United States	2.2
12	Reliance Industries	India	2
13	Formosa Group	Taiwan	1.8
14th	Sumitomo Chemical	Japan	1.7
15th	Polimeri Europa	Italy	1.6

The starting monomers - propene and ethene - are gaseous at room temperature, and when they are interlinked ( polymerization ) they form long molecular chains, the so-called polymers .

The polymerization requires high temperatures, often high pressure and the use of a catalyst system . Mixtures of titanium and aluminum compounds are usually used as catalysts . Without these substances, polyolefin production would not be feasible, which means that the success of polyolefins is based to a large extent on the development of ever more powerful and complex catalyst systems.

Polyolefins are robust, flexible plastics with a wide range of uses.

End products

The most important representatives of this group of plastics are polyethylene (PE), polypropylene (PP) and polymethylpentene (PMP). Furthermore, polyisobutylene (PIB) and polybutylene (PB, polybutene-1) are industrially produced and used polyolefins.

Films , blown films , shrink films , shrink tubing , coatings and packaging are made from low-density polyethylene (LDPE / PE-LD) . Linear-low-density polyethylene (LLDPE / PE-LLD) is mainly used for packaging and plastic containers. High-density polyethylene (HDPE / PE-HD) is a raw material for the manufacture of containers, toys as well as petrol tanks, pipes and household goods. Polypropylene (PP), especially isotactic polypropylene, is used as packaging in the medical and food sectors, for fibers and pipes.

Web links

Commons : Polyolefins  - Collection of images, videos and audio files

Individual evidence

1. ↑ James L. White, David Choi: Polyolefins: Processing, Structure Development, and Properties, Hanser Gardner Publications, 2005.
2. ↑ Cornelia Vasile: Handbook of Polyolefins, 2nd edition, CRC Press, 2000.
3. ↑ polyolefins. Kunststoff-Deutschland, accessed on June 16, 2020 . 
4. ↑ Der Standard , September 15, 2006, p. 23, with reference to CMAI - Chemical Market Associates as a source.