Dacron repeating unit

A typical polyester molecule has 50 to 100 repeat units and a molar mass between 10,000 and 20,000 g/mol. PET can be formed into fibers (such as Dacron) or films (such as Mylar). Mylar films, which can be rolled into sheets 30 times thinner than a human hair, are used to make magnetic recording tape and packaging for frozen food. Dacron is best known for its use in clothing, but it has many other applications. For example, tubes of Dacron are used as synthetic blood vessels in heart bypass operations because Dacron is inert, nonallergenic, and noninflammatory. 

As an example of a polyester fiber, consider the condensation polymer Dacron (also sold as a film—Mylar). The monomeric repeating unit of Dacron is shown in Fig. 7.8.2, with several linked monomers indicated in Fig. 7.8.3. While the... 

Figure 7.8.2 The repeating unit of the condensation polymer Dacron, an example of a polyester.

In addition, among the polyesters, polyethylene terephtalate) or Dacron, is another important member. In Figure 2.39, the repeating unit of polyethylene terephtalate) is shown [8,195], This polymer is applied in the production of fabrics. 

Write a balanced equation for the reaction between 1,4-benzenedicarboxylic acid and 1,2-dihydroxyethane to form the polyester Dacron. Draw an abbreviated structure for the polymer, with brackets around the repeat unit. 

For the polymeric substances nylon and Dacron, sketch representations of the repeating unit... 

A polyester is a polymer in which the polymerization forms an ester group. The repeating unit is an ester thus there are many esters, or "poly-esters." Dacron is an example. 

The strength of a fibre can be increased by drawing, this process being discussed in Section 2.4.4 and illustrated in Fig. 2.12. Common synthetic polymers used to produce fibres are generally polyamides, polyesters or polyacrylics. The class of nylons are the most familiar polyamides. For example, the structure of nylon-6,6 (here the numerals refer to the numbers of carbon atoms between successive amide groups in the repeating unit) is shown in Table 2.1. An example of a polyester is poly(ethylene terephthalate) (PET) (Table 2.1), known commercially in fabrics as tery-lene or dacron (this polymer is also used in PET plastic drink bottles). A well-known polyacrylic used to make fibres is poly(acrylonitrile) (Table 2.1). 

Acidic And Glycol Repeat Units In Terylene (Dacron)... 

The condensation polymers are formed by repeated condensation reaction between two different bi-functional or tri-functional monomeric units. In these pol3nnerisation reactions, the elimination of small molecules such as water, alcohol, hydrogen chloride, etc. take place. The examples are terylene (dacron), nylon 6, 6, nylon 6, etc. For example, nylon 6, 6 is formed by the condensation of hexamethylene diamine with adipic acid. 

When a polymer is made, monomers bond together one after another in a rapid series of steps. A catalyst usually is required for the reaction to take place at a reasonable pace. With some polymers, such as Dacron and nylon, two or more kinds of monomers bond to each other in an alternating sequence. A reaction in which monomer units are bonded together to form a polymer is called a polymerization reaction. The repeating group of atoms formed by the bonding of the monomers is called the structural unit of the polymer. The structural unit of a polymer made from two different monomers has the components of both monomers. 

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