Polyester: Amazing Properties, Applications

Polyester is a man-made fiber. Polyethylene terephthalate, or PET for short, is made by mixing ethylene glycol and terephthalic acid. If it were a person, this would be their legal name. Polyester is a kind of plastic that is manufactured in a laboratory from chemical components.

Polyester is a base material for many industrial, commercial, and household products. Its strength and ability to keep its shape make it useful in a wide range of situations. Polyester is long-lasting, incredibly robust, water-repellent due to its plastic properties, machine-washable, preserves its form, and, most significantly, affordable.

Polyesters Properties and Applications
Polyesters Properties and Applications

What is Polyester?

Polyester is a chemical word that can be broken down into the words poly (which means many) and ester (a basic organic chemical compound). Ethylene, which comes from petroleum, is the main ingredient in making polyester. In this process, ethylene is the polymer, the chemical building block of polyester, and the chemical process that creates the final polyester is referred to as “polymerization.”

polyesters are a type of synthetic polymer that are composed of many identical chemical repeating units covalently bonded together using ester (CO-O) groups.

Repeating Unit in Polyester
Repeating Unit in Polyester

It is a type of man-made fiber or fabric that is made by combining ethylene glycol and pure terephthalic acid, both of which come from petroleum. Together, these make polyethylene terephthalate (PET), which is the same raw material used to make plastic soda bottles.

Most polyesters are made by combining an organic alcohol with hydroxyl (OH) groups and a carboxylic acid. This is called a condensation reaction (containing carboxyl [COOH] groups). These two functional groups combine to make the ester linkage, which is a chemical group with the mentioned structure

Polyesters have a wide range of properties and use in everyday life. Some of the things that are made from this group are permanent-press fabrics, single-use soft-drink bottles, compact discs, rubber tires, and enamel paints.

Properties of Polyester

Polyester contains a variety of properties, many of which are unique to the fabric. Polyester gained popularity and is still used frequently today because of these advantages. Many significant properties of polyester include

  • Polyester is a very robust and durable fabric.
  • Polyester is incredibly tough; it resists most chemicals, stretches and shrinks, wrinkles, mildew, and abrasion.
  • Polyester is hydrophobic by nature, meaning that these molecules dry quickly. By creating hollow fibers, it may be utilized for insulation.
  • Because of its ability to keep its form, polyester is a fantastic material for manufacturing outdoor apparel that can withstand harsh weather.
  • Polyester does not wrinkle, making it simple to wash and dry without the extra strain of ironing.

Uses and Applications of Polyester

Polyester is utilized in the production of several items, including apparel, home furnishings, industrial textiles, computers, audio recordings, and electrical insulation. As it doesn’t absorb moisture, it provides a number of advantages over conventional textiles. It is inherently stain-resistant because to its poor absorbency. The finishing technique for polyester clothes allows for preshrinkage. This prevents it from stretching out of shape and from shrinking. The cloth is resistant to mildew and is simple to color.

Textured polyester fibers are used to fill pillows, quilts, jackets, and sleeping bags because they are efficient, non-allergenic insulators. Because of its great propensity to shed water and strong ability to retain heat, polyester is frequently utilized for base layers. Because of the continual splashing polyester qualities tend to make outer shell layers feel warmer.

  • Polyesters are commonly used in textiles for garments. Polyester yarns and threads are used to weave many different kinds of clothes. Polyester shirts, polyester coats, polyester pants, and polyester caps are just a few examples.
  • Bedsheets, curtains, blankets, and pillows are only few of the various textiles used in the production of polyester-based home furnishings.
  • Upholstery fabric is another common usage for polyester.
  • This polymer also finds significant usage in the production of mouse pads.
  • It is well knowledge that polyester is used extensively in the production of reinforcements for automobile tyres.
  • Conveyor belts frequently utilize polyester textiles.
  • To keep passengers safe, seat belts in cars are constructed from a variety of materials, including polyester.
  • Coated textiles may be created using polyester as well.
  • Polyester is utilized to make pillow filling because of its insulating characteristics and its comparatively soft feel. Padding for furniture is another common application for this fabric.
  • PET base film, which is frequently used for drafting and the replication of engineering designs, is coated with matt, diazo- or silver-sensitized lacquers. This drawing office film is said to be more practical for making alterations to designs later on and can also be stored.
  • In plain paper copying machines, overhead projection transparencies are created using coated PET film. Several methods of printing and writing can be used on overhead projection transparencies.
  • More than 30% of the total PET film used for imaging applications is used as an x-ray basis. A photosensitive coating made of gelatin is often applied to a blue-tinted 175 micron PET film, which is used as medical x-ray film.
  • Polyester textiles are great for use as tablecloths since they are resistant to stains.
  • Certain polyester varieties are also used in the bottle-making process. In addition to natural fibers, some polymers are also used in the fabrication of tarps.
  • Some polyesters are commonly used in the production of liquid crystal displays (typically abbreviated as “LCDs”).
  • Capacitor dielectric films may be produced using polyesters as well.
  • Film insulation is another application for these polymers, found in insulating tapes and some types of wires.
  • Polyester film is widely used in industrial and specialty applications due to its high tensile strength, durability, flex resistance, and clarity. It also exhibits good thermal, chemical, and dimensional stability.
  • Polyester film may be made in a broad variety of thicknesses, from one to several hundred microns, and visible light transmission ranges from basically zero to ninety nine percent. Polyester film’s adaptability and worth as a preferred film are increased by its capacity to be tailored through surface and polymer alteration to match the particular application.
  • It’s worth noting that polyesters can be used as a component in high-quality treatments for specific types of wood. Polyesters are frequently employed as finishes on a wide variety of products, including guitars, interiors, and even some pianos.

History of Polyester

Polyester has a long history, despite the fact that it didn’t become widely used until the 1960s.

  • Around the middle of the 1930s, a guy by the name of W.H. Carothers, who was working for DuPont at the time, found that he could make fibers by combining carboxyl acids and alcohols. Despite being a success, this project was put on hold when Carothers discovered Nylon, a different fabric that is still hugely popular today. Two British researchers, W.K. Birtwhistle and C.G. Ritchie, continued Carothers’ work in 1939. Investigating the polyester produced by combining ethylene glycol and terephthalic acid was not a goal of Carothers’ unfinished study.
  • Two British scientists, Whinfield and Dickson, were the ones to patent PET or PETE in 1941. Synthetic fibers like polyester, Dacron, and terylene are made from polyethylene terephthalate (PET).
  • Whinfield, Dickson, Birtwhistle, and Ritchiethey later that year developed Terylene, the first polyester fiber. Imperial Chemical Industries, also known as ICI, produced terylene for the first time.
  • Imperial Chemical Industries, also known as ICI, sold all of its legal rights to DuPont in 1946. 1950 saw the creation of another polyester fiber under the brand name Dacron by the DuPont-owned Delaware division. In 1952, mylar was developed. In 1951, polyester was initially made available to the American public as the enchanted fabric that didn’t require ironing! The DuPont trademarks PET and PEN are responsible for changing how polyester is used and consumed.
  • Kodel was created by Eastman Chemical Products, Inc. in 1958 after the creation of Terylene and Dacron.
  • Textile mills sprung up all over as the polyester industry expanded quickly. Cheap polyester clothing was made by several of the mills, many of which were situated at modest petrol stations. The business grew quickly until the 1970s as consumers flocked to the affordable, strong fabric. However, the industry was hammered by the iconic double-knit polyester image, and polyester quickly gained a reputation as an unpleasant fabric.

Types of Polyester

Filaments are continuous fibers that are utilized in the production of textiles that are smooth and comfortable. Polyester staples have the appearance of cotton staples that have been spun into a substance that is similar to yarn. Tows are quite similar to polyester filaments, with the key difference being that the filaments are only loosely packed together. Stuffing for pillows, toys, and coats is often made with fiberfill, which consists of continuous filaments of polyester. These filaments provide huge fiber volumes that may be used in bulky items.

Depending on the purpose, some polyester varieties are more suited due to their unique properties.

Polyethylene Terephthalate
Polyester most frequently comes in the form of polyethylene terephthalate. The most widely manufactured polyester is polyethylene terephthalate, sometimes referred to as PET. The majority of applications benefit greatly from the durability and low cost of production of polyethylene terephthalate.

Biodegradable polyester
Polyester can be recycled, however, it is more frequently recycled as bottles than as fabric for garments. Less than 15% of the polyester that is used in fabrics and clothing is actually recycled and utilized in new textiles. Plant-based polyester can help with it.

Plant-based polyester is produced using bio-based petroleum substitutes. Plants like sugar cane and bio-waste, or waste that mostly consists of organic components like food scraps or sawdust, are where the ethylene required for polyester is found. The consumption of petroleum resources is decreased by using these biodegradable materials.

Plant-based polyester fabric is biodegradable but is not as widely made as PET due to greater costs. Given that the crops are grown sustainably, this quality makes plant-based polyester more environmentally friendly and sustainable. Although this sort of polyester might not be as well-liked or long-lasting as others, it is more ecologically friendly.

Polyester PCDT
Although having different chemical structures, PCDT and PET are comparable. This polyester is known as PCDT, or poly-1, 4-cyclohexylene-dimethylene terephthalate. While frequently more elastic and robust than PET, PCDT polyester is less common. These characteristics make this polyester perfect for heavy-duty uses like upholstery or drapes.

Polyester Manufacture

Polyester, unlike natural fibers like cotton, is produced in a lab. Instead, resulting chemicals are used in a chemical process to create polyester. There are five main phases involved in making polyester, however these might vary based on the kind of polyester and the company.

  • The process of turning petroleum into chemicals that may be utilized in a variety of applications begins with the extraction of petroleum from the earth and its transportation to a refinery. The two monomers required to create polyester are ethylene and p-xylene, both of which may be obtained from petroleum.
  • Polyethylene terephthalate (PET), the plastic used in soda and water bottles, is made by combining monomers with dimethyl terephthalate. The consistency of PET in this form is similar to that of honey.
  • Extruding the PET allows it to dry and firm once it has been shaped. After that, it’s pulverized into tiny pellets.
  • Spin the pellets into thread by melting them and then forcing the molten PET through small holes called spinnerets. As these strands of material cool, they crystallize into polyester yarn. Different fiber grades may be made by modifying the spinneret forms to suit a variety of applications.
  • Now that the fibers have been twisted into polyester yarn, they may be knitted into fabric. The fibers can now be snipped or chemically treated to obtain the desired effects.
  • In order to achieve a certain goal, this manufacturing procedure can be altered in a number of ways. To make silky smooth textiles, for instance, the fibers will be manipulated to form a very fine filament. The process’s ethylene can also be modified in many ways. Ethylene is often derived from sugarcane in the production of plant-based polyester, as opposed to petroleum.

Advantages and Disadvantages of Polyester

Polyester, the cheapest and most straightforward of the three synthetic fibers, is also the most often used. In addition, it is long-lasting, malleable, not easily deformed, resistant to corrosion, insulating, and simple to clean and dry. Polyester textiles come in a wide variety of styles. There are many items that are blends or interweaves of other textile fibers in addition to woven pure polyester textiles. These are some benefits and drawbacks of polyester materials:

Advantages

  • Fabrics made from these fibers have excellent wrinkle resistance and strong structural stability.
  • Synthetic fabrics offer superior thermoplasticity and heat resistance.
  • Superior over acrylic in terms of light resistance
  • The price of producing polyester is lower than that of producing cotton or wool. Polyester fibers may be inexpensively mass manufactured in very large quantities. The main benefit of polyester is the decreased prices it brings to consumers.

Disadvantages

  • t is difficult to dye and has low dyeability, but the resulting color is highly stable and resistant to fading.
  • Polyester fabric has low hygroscopicity, so it feels stuffy when you wear it; static electricity is easily attracted;
  • Polyester is not sustainable since it is derived from petroleum and hence takes hundreds of years to decompose. Moreover, fish, other marine life, and even people have been found to swallow microfibers from polyester clothes that have made their way into our rivers.
  • Polyester may not cost much to produce, but it still takes quite a bit of power to get it from raw materials to finished product. Moreover, effluent from industrial processes can get contaminated with harmful compounds and heavy metals utilized in production.

To Learn more to understand what makes polyester so unique, watch the video.

YouTube video

References

  • https://www.thoughtco.com/history-of-polyester-4072579
  • UKEssays. (November 2018). Polyester: History, Development and Applications. Retrieved from https://www.ukessays.com/essays/biology/industrial-application-of-polyester-biology-essay.php?vref=1
  • https://byjus.com/chemistry/uses-of-polyester/
  • P. E. Cassidy, T. M. Aminabhavi and V. S. Reddy, in Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, Inc., Hoboken, NJ, USA, 2000.
  • https://www.raftingmag.com/rafting-magazine/material-polyester
  • https://study.com/academy/lesson/polyester-types-chemical-structure-uses.html
  • https://www.lawrencehuntfashion.com/blogs/news/history-of-polyester-fabrics
  • https://www.apexmills.com/media_post/what-is-polyester/
  • Ravve A (2012). Principles of Polymer Chemistry. New York, New York, NY: Springer.

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Jyoti Bashyal

Jyoti Bashyal is a dedicated researcher specializing in computational chemistry, enzyme inhibition, in-vitro analysis, and sustainable chemistry. Alongside her scientific pursuits, she finds immense joy in creative writing, approaching her work with unwavering determination and a positive outlook. With an open mind and a thirst for knowledge, she embraces new opportunities to learn and grow, embodying the spirit of curiosity and continuous self-improvement.

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