Ethylene glycol Dacron from

Explain the process of condensation polymerization. How might the polymer obtained from benzene-1,2-dicarboxylic acid and ethylene glycol differ from Dacron ... 

How Is dacron obtained from ethylene glycol and terephthalic acid ... 

Problem 16.56 Indicate the reactions involved and show the structures of the following condensation polymers obtained from the indicated reactants (a) Nylon 66 from adipic acid and hexamethylene diamine (b) Nylon 6 from e-caprolactam (c) Dacron from methyl terephthalate and ethylene glycol (d) Glyptal from glycerol and terephthalic acid (e) polyurethane from diisocyanates and ethylene glycol. ... 

Chemically, Dacron and Mylar are polymers made from a ring structure called dimethyl terephthalate and ethylene glycol (HO-CH2CH2-OH). The polymer unit is called polyethylene terephthalate, or PET. Dacron fiber is used in tires and fabrics, and is even used to repair blood vessels. Mylar is used in magnetic recording tape. In the 1960s, it was used in huge balloons that were sent into orbit around Earth. Plastic soda containers are made of PET. 

Just as diacids and diamines react to give polyamides, diacids and dialcohols react to give polyesters. The most industrially important polyester, made from reaction of terephthalic acid (1,4-benzenedicarboxylic acid) with ethylene glycol (1,2-ethanediol), is used under the trade name Dacron to make clothing fiber and under the name Mylar to make plastic film and recording tape. 

Alcohols occur widely in nature. Methanol is also known as wood alcohol because it can be obtained by distilling wood in the absence of air. It is very poisonous and can cause blindness or death if ingested. Ethanol is consumed in alcoholic beverages. Other simple alcohols, such as 2-phenylethanol from roses and menthol from peppermint, are constituents of natural flavors and fragrances. Alcohols are important intermediates in chemical synthesis. They are also commonly used as solvents for various chemical processes. Ethylene glycol is used in antifreeze and in the preparation of polymers such as Dacron. 

The most common polyester, Dacron, is formed from dimethylterephthalate and ethylene glycol. 

Polyester fibers, similar to polyamide fibers, represent another important family of fiber. Polyester fiber was discovered in England in 1941 and commercialized in 1950. Two common trade names of polyester are Dacron in the US and Terylene in the UK. The term polyester fiber represents a family of fibers made of polyethylene terephthalate. Dimethyl terephthalate is reacted with ethylene glycol in the presence of a catalyst, antimony oxide, to produce polyethylene terephthalate or polyester. The chain repeat structure of PET is given in Fig. 4.6. Although polyesters can be both thermosetting and thermoplastic, the term polyester has become synonymous with PET. Note that the PET chain structure is different from the simpler structure of nylon or polyethylene. In PET, the aromatic ring and its associated C-C bonds provide a rigidity to the structure. The polyester structure is also bulkier than that of nylon or polyethylene. These factors make polyester less flexible than nylon and polyethylene, and the crystallization rate of PET slower than that of nylon or polyethylene. Thus, when polyester is cooled from the melt, an appreciable amount of crystallization does not result. 

More than 1 million tons of nylon is produced annually in the United States for use in clothing, carpets, rope, and so on. Many other types of condensation polymers are also produced. For example, Dacron is a copolymer formed from the condensation reaction of ethylene glycol (a dialcohol) and p-terephthalic acid (a dicarboxylic acid) ... 

The pioneer in the field of truly synthetic fibres was Carothers, who demonstrated that two comparatively simple compounds derived from phenol, namely, hexamethylenediamine and adipic acid, could be caused to polymerize to form a potentially fibrous polymer. This was spun into yarn which was successfully placed on the market as nylon. Shortly afterwards ethylene glycol and terephthalic acid were condensed to a polymer from which Terylene or Dacron was made. Ethylene is a by-product in the cracking of petroleum and is the starting point in the manufacture of vinyl chloride and acrlyonitrile, from which Vinyon and the various polyacrylonitrile fibres respectively are spun. 

Condensation polymerization involves the loss of a small molecule, often water or HCl, when monomers are combined. Dacron is more linear than the polymer obtained from benzene-1,2-dicarboxylie acid and ethylene glycol, so Dacron can be more readily spun into yam. 

Mylar A themioplastic film that is produced from the polyester of ethylene glycol and terephthalic acid. The fiber made by this method is called Dacron. Mylar and Dacron are DuPont trade names. 

This linear polyester is isomeric with Dacron, which is prepared from terephthalic acid and ethylene glycol (see the preceding essay). Dacron and the linear polyester made in this experiment are both thermoplastics. 

Whinfield and W. Dickson, working at the Calico Printers Association (2,3). Other polymers pioneered by these workers included poly(l,3-propylene terephthalate), 3GT, poly(l,4-butylene terephthalate), 4GT, and the polyester from ethylene glycol and l,2-6is(4-carbox5 henoxy)ethane, known as CPE-2G or Fiber-0 (4). Of these materials, PET was selected for development as a melt-spinnable synthetic fiber, but commercialization was impossible until after the end of World War II. Eventually, when the various national economies were back on a peacetime footing, PET polymer and fibers derived from it were put into production. The whole market-driving force for polyester at this time was in the form of synthetic fibers. In the United Kingdom, the new material was manufactured by Imperial Chemical Industries Ltd. imder the trade name Terylene, while DuPont introduced it to the United States in 1953 as Dacron (see Polyesters, Fibers). 

Condensation (or step-growth) pol3oners are formed by reacting difunctional molecules, usually with the elimination of water. One example is the formation of polyethylene terephthalate (the polyester used for Terylene and Dacron fibres and transparent films and bottles) from ethylene glycol and terephthalic acid ... 

A useful polyester is prepared from terephthalic acid and ethylene glycol. More than 2 million tons of this polymer is produced annually in the United States. Dacron, the fiber produced from this polyester, accounts for approximately 50% of all synthetic fibers. It absorbs very little moisture, and its properties are nearly the same whether it is wet or dry. 

Polyesters are similarly made through the reactions of diacids with diols—simple Fischer esterification reactions that produce a polymeric structure. For example. Dacron and Mylar are trade names for different polyesters that are made from ethylene glycol... 

Dacron is the trade name for the condensation copolymer formed from ethylene glycol (a diol—a molecule with two alcohol groups) and para-terephthalic acid (a diacid- a molecule with two carboxy groups). The condensation reaction removes the hydrogen atom from the alcohol on one monomer and the OH group from the carboxy group on a second monomer, producing water. 

Resins with long-chain macromolecules obtained by polycondensation have thermoplastic properties. Polyesters ( Terylene ) and polyamides (Nylon) are examples of polycondensations. The synthetic fibre Terylene (known as Dacron in the USA) is a polyester formed by the reaction of ethylene glycol with terephthalic acid the latter is obtained from p-xylene by oxidation ... 

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