Polyester (aka Terylene) is a category of polymers which contain the ester functional group in their main chain. The scanning electron microscope ( SEM) is a type of Electron microscope that images the sample surface by scanning it with a high-energy beam of Electrons Fiber or fibre is a class of Materials that are continuous filaments or are in discrete elongated pieces similar to lengths of thread. Uses PET can be semi-rigid to rigid depending on its thickness and is very lightweight A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate (PET). Uses PET can be semi-rigid to rigid depending on its thickness and is very lightweight Polyesters include naturally-occurring chemicals, such as in the cutin of plant cuticles, as well as synthetics such as polycarbonate and polybutyrate. Cutin is one of two Waxy polymers that are the main components of the Plant cuticle which covers all aerial surfaces of Plants The other major cuticle polymer Plant cuticles are a protective waxy covering produced only by the epidermal cells of leaves, young shoots and all other aerial plant organs without Periderm Polybutyrate (short for polybutyrate adipate terephthalate or PBAT is a Biodegradable Aliphatic - Aromatic Polyester Plastic.
Polyesters may be produced in numerous forms such as fibers, sheets and three-dimensional shapes. Polyesters as thermoplastics may change shape after the application of heat. A thermoplastic is a Plastic that Melts to a liquid when heated and freezes to a Brittle, very Glassy state when cooled sufficiently While combustible at high temperatures, polyesters tend to shrink away from flames and self-extinguish upon ignition. Polyester fibers have high tenacity and E-modulus as well as low water absorption and minimal shrinkage in comparison with other industrial fibers.
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Applications
Polyesters are the most widely used man-made fiber in the world. Woven polyester fabrics are used in consumer apparel and home furnishings such as bed sheets, bedspreads, curtains and draperies. Similarly, industrial polyesters are used in tyre reinforcements, ropes, fabrics for conveyor belts, safety belts, coated fabrics and plastic reinforcements with high energy absorption. Polyester fiberfills are also used to stuff pillows, comforters and cushion padding.
Polyester fabrics are claimed to have a "less natural" feel when compared to similarly-woven fabrics made from natural fibers (i. e. cotton in textile uses). Cotton is a soft staple Fibre that grows around the seeds of the cotton plant ( Gossypium sp However, polyester fabrics may exhibit other advantages over natural fabrics, such as improved wrinkle resistance. As a result, polyester fibers are sometimes spun together with natural fibers to produce a cloth with blended properties.
Polyesters are also used to make bottles, films, tarpaulin, canoes, liquid crystal displays, holograms, filters, dielectric film for capacitors, film insulation for wire and insulating tapes. A tarpaulin or tarp is a large sheet of strong flexible Water resistant or Waterproof material often Cloth such as Canvas or polyester Holography (from the Greek, ὅλος - hólos whole + γραφή - grafē writing drawing is a technique that allows the In Chemistry and common usage a filter is a device (usually a membrane or layer that is designed A dielectric is a nonconducting substance ie an insulator. The term was coined by William Whewell in response to a request from Michael Faraday. A capacitor is a passive electrical component that can store Energy in the Electric field between a pair of conductors An insulator, also called a Dielectric, is a material that resists the flow of Electric current. A wire is a single usually cylindrical, elongated string of drawn Metal.
Liquid crystalline polyesters are among the first industrially-used liquid crystalline polymers. They are used for their mechanical properties and heat-resistance. These traits also important in their application as an abradable seal in jet engines.
Thermosetting polyester are used as casting materials, fiberglass laminating resins, and non-metallic auto-body fillers. Thermosetting plastics thermosets are Polymer materials that irreversibly cure form Casting is a manufacturing process by which a liquid material is (usually poured into a mold which Fiberglass (also called fibreglass and glass fibre see Spelling differences) is material made from extremely fine Fibers of Glass. Fiberglass-reinforced, unsaturated polyesters find wide application in bodies of yachts and as body parts of cars.
Polyesters are also widely used as a finish on high-quality wood products such as guitars, pianos and vehicle / yacht interiors. The guitar is a Musical instrument with ancient roots that is used in a wide variety of musical styles The piano is a Musical instrument played by means of a keyboard that produces sound by striking steel strings with Felt covered hammers Burns Guitars, Rolls Royce and Sunseeker are a few companies that use polyesters to finish their products. Burns London is a guitar-making company originally formed in 1960 as Ormston Burns Ltd A Rolls-Royce car may refer to vehicles produced by Rolls-Royce Limited (1906-1973 Rolls-Royce Motors (1973-2003 which was owned Sunseeker International, is a UK luxury motor Yacht manufacturer Thixotropic properties of spray-applicable polyesters make them ideal for use on open-grain timbers, as they can quickly fill wood grain, with a high-build film thickness per coat. Thixotropy is the property of some non-Newtonian pseudoplastic fluids to show a time-dependent change in Viscosity; the longer the fluid undergoes Cured polyesters can be sanded and polished to a high-gloss, durable finish.
Polyester fiber properties
1. Mechanical properties
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Energy absorption of chemical fiber reinforced plastics (impact, bending and tensile tests) Investigation of the practical requirements for measuring the energy absorption of composite materials, and development of a suitable method for carrying out such measurements. A number of dynamic testing methods for measuring the energy absorption of laminates are reviewed, including animpact bending test, repeated-impact tests, an impact tensile test, and a ram bending test. Also discussed are impact tests on plate laminates. Particular emphasis is placed in these studies on composites with a chemical fiber reinforcement. It is established that a relation exists between the quasi-static energy absorption of the fibers and the dynamic energy absorption of the composite. Composites with commercial polyester and polyamide fibers lead to the highest energy absorptions, in which case the testing apparatus has a significant effect.
2. Chemical properties
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==The polyester industry==:)
Some basics
To get an idea about coverage, importance and complexity of the polyester industry, some basic information about polyester or polyethylene terephthalate (PET) at first:
What is polyester? Polyester is a synthetic polymer made of purified terephthalic acid (PTA) or its dimethyl ester dimethyl terephthalate (DMT) and monoethylene glycol (MEG). Uses PET can be semi-rigid to rigid depending on its thickness and is very lightweight Terephthalic acid is one Isomer of the three Phthalic acids. It finds important use as a Commodity chemical, principally as a starting compound Dimethyl terephthalate (DMT is an Ester of Terephthalic acid and Methanol and is used in the production of Polyesters including Polyethylene Ethylene glycol ( monoethylene glycol ( MEG) 12-ethanediol, IUPAC name: ethane-12-diol) is an Alcohol with two -OH It ranges after polyethylene and polypropylene at the third place in terms of market size.
The main raw materials are described as follows:
Purified Terephthalic Acid – PTA – CAS-No. : 100-21-0 Synonym: 1,4 Dibenzenedicarboxylic acid, Sum formula; C6H4(COOH)2 , mol weight: 166,13
Dimethylterephthalate – DMT- CAS-No: 120-61-6 Synonym: 1,4 Dibenzenedicarboxylic acid dimethyl ester Sum formula C6H4(COOCH3)2 , mol weight: 194,19
Mono Ethylene Glycol – MEG – CAS No. : 107-21-1 Synonym: 1,2 Ethanediol Sum formula: C2H6O2 , mol weight: 62,07
More information about polyester raw materials one can find for PTA [1],DMT [2] and MEG [3], at the webpage INCHEM "Chemical Safety Information from Intergovernmental Organizations".
To make finally a polymer of high molecular weight one needs a catalyst. The most common catalyst is antimony trioxide (or antimony tri acetate)
Antimony trioxide – ATO – CAS-No. Antimony trioxide is the Chemical compound with the formula Sb2O3 : 1309-64-4 Synonym: non, mol weight: 291,51 Sum formula: Sb2O3
In 2008 about 10 000 t Sb2O3 are used to produce around 49 Mio t polyethylene terephthalate.
Polyester is described as follows:
Polyethylene Terephthalate CAS-No. : 25038-59-9 Synonym / abbreviations: polyester, PET, PES Sum Formula: H-[C10H8O4]-n=60-120 OH, mol unit weight: 192,17
What are the success factors of the unbroken capacity growth of polyethylene terephthalate?
->The relatively easy accessible raw materials PTA or DMT and MEG ->The very well understood and described simple chemical process of polyester synthesis ->The low toxicity level of all raw materials and side products during production and processing ->The possibility to produce PET in a closed loop at low emissions to the environment ->The outstanding mechanical and chemical properties of polyester ->The recycle ability ->The wide variety of intermediate and final products made of polyester
All these facts are making this polymer one of the key elements of our daily life.
In table 1 we see the estimated world polyester production for textile polyester, bottle polyester resin, film polyester mainly for packaging and specialty polyesters for engineering plastics, which are the main fields of application. A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Packaging is the science art and technology of enclosing or protecting products for distribution storage sale and use According to this table, the world's total polyester production might exceed 50 million tons per annum before the year 2010.
Table 1: World polyester production
Market size - year
2002 [Mio t/a] 2008 [Mio t/a]
Product Type
Textile-PET 20 39
Resin, Bottle/ A-PET 9 16
Film-PET 1,2 1,5
Special Polyester 1,0 2,5
TOTAL 31,2 49,0
With its production volume and product diversity, polyester ranges after polyethylene (33. Polyethylene or polythene ( IUPAC name poly(ethene) is a Thermoplastic commodity heavily used in consumer products (notably the 5%), polypropylene (19,5%) with a market share of about 18% in third position among all plastic materials produced worldwide. Polypropylene or polypropene ( PP) is a Thermoplastic Polymer, made by the Chemical industry and used in a wide variety of applications
The polyester production chain, and the relative polyester industry chain, will now be explained in greater detail and step by step.
Raw material producer
The raw materials PTA, DMT and MEG are mainly produced by large chemical companies which are sometimes integrated down to the crude oil refinery where p-xylene is the base material to produce PTA and liquefied petroleum gas (LPG) is the base material to produce MEG. Liquefied petroleum gas (also called LPG, GPL, LP Gas, or Autogas) is a mixture of Hydrocarbon Gases used as a Fuel
Large PTA producers are for instance BP, Reliance, Sinopec, SK-Chemicals, Mitsui and Eastman Chemicals. MEG production is in the hand of about 10 global players which are headed by MEGlobal a JV of DOW and PIC Kuweit followed by Sabic.
Let us assume the average production capacity of a single polyester plant is about 200 t/day: we are talking about nearly 500 polyester plants around the globe. Adding to this figure the continuously-growing polyester recycling industry, which is estimated to have processed about 3 million t polyester waste in 2007 alone (5 million T/a in 2010 estimated) and where each plant produces on average about 10 000 t/a, we have another 500 plants. This is 1000 polyester production plants, all needing specific and polyester-dedicated engineering and equipment, machinery, process technology and know-how, producing, processing and recycling polyester.
Among the world's largest polyester producers are the following companies:
Artenius, Advansa, DAK, DuPont, Eastman/Voridian, Hyosung, Huvis, Indorama, Invista, Jiangsu Sanfangxian, M&G Group, Mitsui, Mitsubishi, NanYa Plastics,Reichhold, Reliance, Rongsheng, Sabic, Teijin, Toray, Tonkun, Tuntex, Wellman, Yizheng Sinopec and Sanfanxiang.
One should notice that China's capacity to produce and process polyester in more than 500 plants is nearly half that of the world's polyester capacity meanwhile. More information about polyester in China can be found under the web site of China Chemical Fiber Economic Information Network [4].
Polyester processing
After the first stage of polymer production in the melt phase, the product stream divides into two different application areas which are mainly textile applications and packaging applications. In figure 2 the main applications of textile and packaging polyester are listed.
Table 2: Textile and packaging polyester application list
POLYESTER-BASED POLYMER (MELT or PELLETS)
Textile Packaging
Staple fiber (PSF) Bottles for CSD, Water, Beer, Juice, Detergents
Filaments POY, DTY, FDY A-PET Film
Technical yarn and tire cord Thermoforming
Non-woven and spunbond BO-PET Biaxial oriented Film
Mono-filament Strapping
Abbreviations: PSF = Polyester Staple Fiber; POY = Partially Oriented Yarn; DTY = Draw Textured Yarn; FDY = Fully Drawn Yarn; CSD = Carbonated Softdrink; A-PET = Amorphous Polyester Film; BO-PET = Biaxial Oriented Polyester Film;
A comparable small market segment (<< 1 million t/a) of polyester is used to produce engineering plastics and masterbatch. A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Packaging is the science art and technology of enclosing or protecting products for distribution storage sale and use
In order to produce the polyester melt with a high efficiency, high-output processing steps like staple fiber (50–300 t/d per spinning line) or POY /FDY (up to 600 t/d split into about 10 spinning machines) are meanwhile more and more horizontal, integrated, direct processes. This means the polymer melt is directly converted into the textile fibers or filaments without the common step of pelletizing. We are talking about full horizontal integration when polyester is produced at one site starting from crude oil or distillation products in the chain oil -> benzene -> PX -> PTA -> PET melt -> fiber / filament or bottle-grade resin. Such integrated processes are meanwhile established in more or less interrupted processes at one production site. Eastman Chemicals introduced at first the idea to close the chain from PX to PET resin with their so-called INTEGREX® process. The capacity of such horizontal, integrated productions sites is >1000 t/d and can easily reach 2500 t/d.
Besides the above mentioned large processing units to produce staple fiber or yarns, there are ten thousands of small and very small processing plants, so that one can estimate that polyester is processed and recycled in more than 10 000 plants around the globe. This is without counting all the companies involved in the supply industry, beginning with engineering and processing machines and ending with special additives, stabilizers and colors. This is a gigantic industry complex and it is still growing by 4–8% per annum, depending on the world region. Useful information about the polyester industry can be found under [5] where a “Who is Producing What in the Polyester Industry” is gradually being developed.
Synthesis
Synthesis of polyesters is generally achieved by a polycondensation reaction. See "condensation reactions in polymer chemistry". A condensation reaction is a Chemical reaction in which two Molecules or moieties ( Functional groups) combine to form one single molecule together with The General equation for the reaction of a diol with a diacid is : (n+1) R(OH)2 + n R´(COOH)2 ---> HO[ROOCR´COO]nROH + 2n H2O
Azeotrope esterification
In this classical method, an alcohol and a carboxylic acid react to form a carboxylic ester. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Carboxylic acids are Organic acids characterized by the presence of a Carboxyl group, which has the formula -C(=OOH usually written -COOH or -CO2H To assemble a polymer, the water formed by the reaction must be continually removed by azeotrope distillation. An azeotrope (pronounced
Alcoholic transesterification
See main article on transesterification. In Organic chemistry, transesterification is the process of exchanging the Alcohol group of an Ester compound with another Alcohol.
O
\\
C - OCH3 + OH[Oligomer2]
/
[Oligomer1]
|
 |
O
\\
C - O[Oligomer2] + CH3OH
/
[Oligomer1]
|
| (ester-terminated oligomer + alcohol-terminated oligomer) | (larger oligomer + methanol) |
Acylation (HCl method)
The acid begins as an acid chloride, and thus the polycondensation proceeds with emission of hydrochloric acid (HCl) instead of water. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water This method can be carried out in solution or as an enamel. In a discussion of Material science, enamel (or vitreous enamel or porcelain enamel in U
- Silyl method
- In this variant of the HCl method, the carboxylic acid chloride is converted with the trimethyl silyl ether of the alcohol component and production of trimethyl silyl chloride is obtained
Acetate method (esterification)
- Silyl acetate method
Ring-opening polymerization
Aliphatic polyesters can be assembled from lactones under very mild conditions, catalyzed anionically, cationically or metallorganically. In Organic chemistry, compounds composed of Carbon and Hydrogen are divided into two classes Aromatic compounds which contain Benzene rings lactone is a cyclic Ester in Organic chemistry. It is the condensation product of an Alcohol group and a Carboxylic acid An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Organometallic chemistry is the study of Chemical compounds containing bonds between Carbon and a Metal.
Thermosetting
Thermosetting resins are generally copolymers of unsaturated polyesters with styrene. Resin, not to be confused with Rosin, is a Hydrocarbon Secretion of many Plants particularly coniferous trees. Styrene, also known as vinyl benzene as well as many other names (see table is an Organic compound with the Chemical formula C6H5CH=CH2 Polyester saturation is governed through the use of maleic acid or fumaric acid. Maleic acid or ( Z)-butenedioic acid or cis -butenedioic acid or malenic acid or maleinic acid or toxilic Fumaric acid is the Chemical compound with the formula HO2CCH=CHCO2H In vinyl esters, saturation (or lack thereof) is found in the alcohol group of the polyester. Vinyl Ester, or Vinylester, is a resin produced by the esterification of an Epoxy resin with an unsaturated monocarboxylic acid. The double bond of unsaturated polyester reacts with styrene resulting in a 3-D cross-linked structure. This structure acts as a thermoset. The cross-linking is initiated through an exothermic reaction involving an organic peroxide, such as methyl ethyl ketone peroxide or benzoyl peroxide. Cross-links are bonds that link one Polymer chain to another They can be Covalent bonds or Ionic bonds "Polymer chains" can refer In Thermodynamics, the word exothermic "outside heating" describes a process or reaction that releases Energy usually in the form of Heat, but Organic peroxides are Organic compounds containing the Peroxide Functional group (ROOR' Methyl ethyl ketone peroxide (MEKP is an Organic peroxide, a high explosive similar to Acetone peroxide. Benzoyl peroxide (ˈbɛnzɔɪl pəˈrɒksaɪd is a Chemical in the Organic peroxide family
References
- Textiles, by Sara Kadolph and Anna Langford. 8th Edition, 1998.
External links
Dictionary
polyester
-noun
- Any polymer whose monomers are linked together by ester bonds
- A material or fabric made from polyester polymer
-adjective
- Of, or consisting of polyesters
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