Condensation polymer nylon

As noted in the Concept Check on page 418, the compound 6-aminohexanoic acid is used to make the condensation polymer nylon-6. Polymerization is not always successful, however, because of a competing side reaction. What is this side reaction Would polymerization be more likely in a dilute solution of this monomer or in a concentrated solution Why ... 

The polymeric amides, polyamides, are an especially important class of condensation polymers. Nylon is the best known polyamide. It is prepared by heating anhydrous hexa-methylenediamine with anhydrous adipic acid, a dicarboxylic acid. This substance is often called nylon 66 because the parent diamine and dicarboxylic acid each contain six carbon atoms. 

Condensation polymers nylon, teflon, polymethane, polycarbonate, amino resins, alkyl resins, and silicone resins... 

ABSTRACT. Chemical interactions (additional condensation and transreactions) on the interfaces of condensation polymers (nylons and polyesters) are discussed. In addition to the recently discovered phenomenon of chemical healing, a new type of composites from polymer blends - the microfibrillar reinforced ones are introduced. It is demonstrated that interfacial chemical Interactions result in the formation of a new interphase representing a copolymer of the blended components and playing the role of selfcompatibilizer. 

As shown, PET is prepared by successive Fischer esterification reactions. Since the polymer is generated via condensation reactions, it is called a condensation polymer. Because PET has repeating ester moieties, the polymer is also classified as a polyester. like PET, nylon 6,6 is also prepared via condensation reactions and is also a condensation polymer. Nylon 6,6 is a polyamide, which is prepared from adipic acid and 1,6-hexanediamine. 

The product that forms between the reaction of two monomers is called a dimer. The polymer (nylon 6,6) forms as the dimer continues to add more monomers. Polymers that eliminate an atom or a small group of atoms during polymerization are called condensation polymers. Nylon 6,6 and other similar nylons can be drawn into fibers and used to make consumer products such as panty hose, carpet fibers, and fishing line. Table 20.11 shows other condensation polymers. 

The leader of DuPont s effort was Wallace H Carothers who reasoned that he could reproduce the properties of silk by constructing a polymer chain held together as is silk by amide bonds The neces sary amide bonds were formed by heating a dicar boxylic acid with a diamine Hexanedioic acid adipic acid) and 1 6 hexanediamme hexamethylenedi-amine) react to give a salt that when heated gives a polyamide called nylon 66 The amide bonds form by a condensation reaction and nylon 66 is an example of a condensation polymer... 

Howardt describes a model system used to test the molecular weight distribution of a condensation polymer The polymer sample was an acetic acid-stabilized equilibrium nylon-6,6. Analysis showed it to have the following end group composition (in equivalents per 10 g) acetyl = 28.9,... 

The packaging (qv) requirements for shipping and storage of thermoplastic resins depend on the moisture that can be absorbed by the resin and its effect when the material is heated to processing temperatures. Excess moisture may result in undesirable degradation during melt processing and inferior properties. Condensation polymers such as nylons and polyesters need to be specially predried to very low moisture levels (3,4), ie, less than 0.2% for nylon-6,6 and as low as 0.005% for poly(ethylene terephthalate) which hydrolyzes faster. 

The name Nylon was given by the Du Pont company of America to their first synthetic condensation polymer formed by the reaction of difuncfional acids with difuncfional amines, ft had been made as part of the fundamental programme of W. H. Carothers to investigate the whole topic of polymerisation. The term has gradually been extended to other related polymers. These materials are strictly polyamides, but this term includes that otherwise distinct class of natural macromolecules, the proteins. The term nylon is retained for its usefulness in distinguishing synthetic polyamides from the broader class of such polymers. 

The most common form of step growth polymerization is condensation polymerization. Condensation polymers are generally formed from simple reactions involving two different monomers. The monomers are difunctional, having a chemically reactive group on each end of their molecules. Examples of condensation polymerization are the formation of nylon 66, a polyamide, and of poly(ethylene terephthalate), a polyester. Because condensation poly-... 

Nylon 66 is a condensation polymer made from adipic acid and iiexamethylenediamine. Nylon 6 is made by ring-opening polymerization of caprolactam. 

Condensation polymers, which are also known as step growth polymers, are historically the oldest class of common synthetic polymers. Although superseded in terms of gross output by addition polymers, condensation polymers are still commonly used in a wide variety of applications examples include polyamides (nylons), polycarbonates, polyurethanes, and epoxy adhesives. Figure 1.9 outlines the basic reaction scheme for condensation polymerization. One or more different monomers can be incorporated into a condensation polymer. 

Linear condensation polymers are produced when the constituent monomers contain two functional groups each. When a single monomer is polymerized, the product is made of chains whose repeat unit corresponds to the monomer. An example of this type is nylon 6, the structure of which is shown in Fig. 1.10. If two different monomers are polymerized, the result most often is a chain whose repeat unit corresponds to the two different monomers arranged alternately. An example of this type is nylon 66, the structure of which is shown in... 

The end group functionality of condensation polymers is typically defined by the monomers employed to make these materials. An example is shown below for a common polyamide polymer, namely nylon (see Figure 2). These polymers... 

Multiple amide groups link the resultant polymer. For this reason, this condensation polymer is a polyamide however, DuPont did not like this name, so we now know this polymer to be an example of a nylon. If the units joined by the... 

Nylon-66 is made by the condensation polymerization of the dicarboxylic acid adipic acid, and 1,6-diaminohexane, an amine. (The number 66 comes from the fact that each of the two reactants contains six carbon atoms.) This reaction results in the formation of amide bonds between monomers, as shown in Figure 2.13. Condensation polymers that contain amide bonds are called nylons or polyamides. Condensation polymers that contain ester bonds are called polyesters. Polyesters result from the esterification of diacids and dialcohols. 

Classify each polymer as an addition polymer (formed by addition polymerization) or a condensation polymer (formed by condensation polymerization). Then classify each condensation polymer as either a polyester or a nylon (polyamide). 

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. 

Most addition polymers are formed from polymerizations exhibiting chain-growth kinetics. This includes the typical polymerizations, via free radical or some ionic mode, of the vast majority of vinyl monomers such as vinyl chloride, ethylene, styrene, propylene, methyl methacrylate, and vinyl acetate. By comparison, most condensation polymers are formed from systems exhibiting stepwise kinetics. Industrially this includes the formation of polyesters and polyamides (nylons). Thus, there exists a large overlap between the terms stepwise kinetics and condensation polymers, and chainwise kinetics and addition (or vinyl) polymers. A comparison of the two types of systems is given in Table 4.1. 

Interfacially formed condensation polymers such as polyesters, polycarbonates, nylons, and PUs are typically formed on a microscopic level in a chain-growth manner largely because of the highly reactive nature of the reactants employed for such interfadal polycondensations. 

Condensation polymers include many of the materials referred to as synthetic or manmade fibers including polyesters (especially PET) and a variety of nylons (mainly nylon 6,6 and nylon 6). 

A number of plastics are condensation polymers and include polyesters and nylons that are not as highly oriented as the same materials but in fiber form. Other plastics have been developed that have outstanding heat stability, strength, and other properties that allow their wide use. These plastics include polycarbonates, polyimides, polybenzimidazoles, polysulfides, polyethers, polysulfones, and polyketones. 

Morgan, P.W. 1965. Condensation Polymers by Interface and Solution Methods. Wiley, New York. Morgan, P.W. and Kwolek, S.L. 1959. The nylon rope trick. J. Chem. Ed., 36 182. 

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