Name the monomers of the above polyester
Answers
Answer:
The following are the composing monomers of polyester:
Explanation:
Ethane-1/2-diol and benzene-1/4-dicarboxylic acid which is, according to some sources, also called terephthalic acid.
Thanks.
Answer:
Polyester is made up of the monomer which is a combination of Ethane-1,2-diol and benzene-1,4-dicarboxylic acid (terephthalic acid). The polyesters have a wide number of uses depending upon the orientation of the different monomers present in the polymer.
Explanation:
Uses of polyesters
Polyesters are extremely important polymers. Their most familiar applications are in clothing, food packaging and plastic water and carbonated soft drinks bottles.
The most used of the polyesters has the formula:
Being an ester, it is made from an acid, benzene-1,4-dicarboxylic acid (terephthalic acid), and an alcohol, ethane-1,2-diol.
It is often known by its trivial name, polyethylene terephthalate (PET).
The annual world wide production of PET is approximately 40 million tonnes and is growing at ca 7% per year. Of this, about 65% is used to make fibres, 5% for film and 30% for packaging.
Another useful polyester is produced from benzene-1,4-dicarboxylic acid and propane-1,3-diol (which replaces ethane-1,2-diol). It is known by its trivial name, polytrimethylene terephthalate.
The different uses of polyesters depend on their structure. The benzene rings in the molecular chain give them a rigid structure, leading to high melting points (over 500 K) and great strength. They do not discolour in light.
In PET fibres, the molecules are mainly arranged in one direction, in film, they are in two directions and for packaging, they are in three directions.
The polyester is produced as small granules. These are melted and squeezed through fine holes and the resulting filaments spun to form a fibre. This fibre, commonly known as Terylene or Dacron, is widely used in clothing (for example, in suits, shirts and skirts) either alone or in blends with other manufactured or natural fibres, principally cotton.
It is also used for filling anoraks and bedding duvets to give good heat insulation. Other uses include car tyre cords, conveyor belts and hoses, where its strength and resistance to wear are paramount.
The polyester can also be made into thin films which can be used in food packaging, audio and video tapes, electrical insulation, and X-ray films.
As packaging
A relatively newer use is for packaging, for example for bottles (see Figure 3). The small granules of the polyester are heated to about 500 K and further polymerization takes place. This heating is sometimes called solid-state polymerizing. The polymer is melted, moulded and then stretched. The molecules are now orientated in three directions giving the plastic great strength.