Polymers Large molecules condensation

We ll explore synthetic polymers, large molecules formed from low molecular weight monomer molecules. Polymers are formed most commonly via addition or condensation polymerization reactions. Their physical and chemical properties make polymers suitable for many practical uses. 

Polyethylene (Section 6 21) A polymer of ethylene Polymer (Section 6 21) Large molecule formed by the repeti tive combination of many smaller molecules (monomers) Polymerase chain reaction (Section 28 16) A laboratory method for making multiple copies of DNA Polymerization (Section 6 21) Process by which a polymer is prepared The principal processes include free radical cationic coordination and condensation polymerization Polypeptide (Section 27 1) A polymer made up of many (more than eight to ten) amino acid residues Polypropylene (Section 6 21) A polymer of propene Polysaccharide (Sections 25 1 and 25 15) A carbohydrate that yields many monosacchande units on hydrolysis Potential energy (Section 2 18) The energy a system has ex elusive of Its kinetic energy... 

Nylon, also a linear polymer, is made by a condensation reaction. Two different kinds of molecule react to give a larger molecule, and a by-product (usually HjO) the ends of large molecules are active, and react further, building a polymer chain. Note how molecules of one type condense with those of the other in this reaction of two symmetrical molecules... 

A polymer is a large molecule built up by the repetition of small, simple chemical units. In some cases the repetition is linear while in other cases the chains are branched or interconnected to form three-dimensional networks. The polymer can be formed not only through linear addition, but also through condensation of similar units as well. 

A chemical reaction by which small molecules (of monomer) are joined together to form large molecules (of polymer). Polymerisation may be effected by (a) addition, in which the polymer molecule is a multiple of the monomer molecule, (b) by condensation, in which the empirical formula of the polymer differs from that of the monomer, and (c) by copolymerisation, in which the polymer molecule is built up from two or more different monomers... 

A condensation polymer may be defined as a polymer wherein the polymer unit contains fewer atoms less than the monomers from which the polymer is produced. In polymer formation, the condensation occurs between two polyfunctional molecules to produce a large molecule. 

The classification of a condensation polymer Is historically based on the observation that during polymerization a small molecule, such as water, is condensed or removed as part of the reaction. There are a large number of polymers produced from condensation reactions and only a representative sample is presented in... 

In addition polymerisation, the molecules of the same or different monomers add together to form a large polymer molecule. Condensation polymerisation is a process in which two or more bi-functional molecules undergo a series of condensation reactions with the elimination of some simple molecules and leading to the formation of polymers. 

Polymers are large molecules (macromolecules) that consist of one or two small molecules (monomers) joined to each other in long, often highly branched, chains in a process called polymerization. Both natural and synthetic polymers exist. Some examples of natural polymers are starch, cellulose, chitin (the material of which shells are made), nucleic acids, and proteins. Synthetic polymers, the subject of this chapter, include polyethylene, polypropylene, polystyrene, polyesters, polycarbonates, and polyurethanes. In their raw, unprocessed form, synthetic polymers are sometimes referred to as resins. Polymers are formed in two general ways by addition or by condensation. 

Polymers are made from the repeating units through two process. One process simply adds each succeeding monomer onto the chain through various methods, called addition polymerization. Condensation polymerization is the second process of adding monomers onto the chain to make large molecules. In condensation polymerization, small molecules like water are removed as the monomer unit is added onto the chain. 

Polymerization is basically the bonding of two or more monomers to produce polymers/plastics (Chapter 1). A chemical reaction, addition or condensation, in which the molecules of a monomer are linked together to form large molecules whose molecular weight is a multiple of that of the original substance result in high molecular weight components. 

This reaction involves reacting different monomers to form polymers and large molecules with the elimination of, e.g. water or HC1, in the process. The same rules apply as for the addition process and the polymers formed by this process can be used to prepare both thermoplastic and thermosetting plastics. Table 4.2 is a list of common polymers prepared by the condensation process. 

Polyesters (short for pOi meric esters ) are condensation polymers that are formed when dihydric alcohols react with dicarhoxylic acids. An ester linkage is formed at each end of each monomer molecule to build up large molecules. A useful polyester is prepared from terephthalic acid and ethylene glycol. 

Polymers are extremely large molecules that are made of repeat units called monomers. Addition polymers are formed from unsaturated monomers that commonly link through free-radical reactions. Most condensation polymers are formed by linking two types of monomer through a dehydration-condensation reaction. 

Polymerization is the process of chemically bonding monomer building blocks to form large molecules. Commercial polymer molecules are usually thousands of repeat units long. Polymerization can proceed by one of several methods. The two most common methods are called addition polymerization and condensation polymerization. 

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