Step-growth polymer table

To see why the assumption of equal reactivity is so important to step-growth polymers, recall from Table 1.2 the kind of chemical reactions which produce typical condensation polymers ... 

The alkene and diene polymers discussed in Sections 7.10 and 14.6 are called chain-growth polymers because they are produced by chain reactions. An initiator adds to a C=C bond to give a reactive intermediate, which adds to a second alkene molecule to produce a new1 intermediate, which adds to a third molecule, and so on. By contrast, polyamides and polyesters are called step-growth polymers because each bond in the polymer is formed independently of the others. A large number of different step-growth polymers have been made some of the more important ones are shown in Table 21.2. 

Table 21.2 Some Common Step-Growth Polymers and Their Uses...

A summary of properties of chain growth and step growth polymers can be found in Table 2.4. 

Table 2-3 lists examples of monomers and their corresponding polymers, with names, for a number of step-growth polymers. 

Table 2-3. Names and-structures for common monomers and step-growth polymers. ...

A characteristic common to the monomers of all condensation, or step-growth, polymers is that they possess two (or more than two) more-or-less reactive functional groups. The functional groups of a single monomer may be different, in which case the polymer may be produced by reaction of the single monomer with itself (Table 20.1, first two examples) or the functional groups required for condensation reactions may be on different monomers, in which case two monomers are required (Table 20.1, last three examples). Examples 1, 2, and 4 from this table are also typical of polycondensations in which a small molecule is split out, water in the first two cases and alcohol in... 

The polymers we have discussed so far are formed from only one type of monomer and are called homopolymers. Often, two or more different monomers are used to form a polymer. The resulting product is called a copolymer. Increasing the number of different monomers used to form the copolymer dramatically increases the number of different copolymers that can be formed. Even if only two kinds of monomers are used, copolymers with very different properties can be prepared by varying the amounts of each monomer. Both chain-growth polymers and step-growth polymers can be copolymers. Many of the synthetic polymers used today are copolymers. Table 28.6 shows some common copolymers and the monomers from which they are synthesized. 

Although sometimes the classifications of condensation and step-growth polymers are considered to be interchangeable, as well as those of addition and chain-growth polymers, one must be aware that the classification of a polymer only by structure or only by mechanism may lead to ambiguities. Odian [8] recommends to classify a polymer attending both, structure and mechanism, in order to avoid this problem. Tables 1.3 and 1.4 contain examples of common addition and condensation polymers, respectively. 

TABLE 3.2 Some Step-Growth Polymers and their Synthesis Reactions... 

Table 2.4 Unking groups in step-growth polymers and example structures... 

The repeat groups for several well-known step-growth polymers of industrial importance are shown in Table 7.1. Step-growth polymerizations that produce small byproduct molecules (aU examples in Table 7.1, except for polyurethane) are commonly called condensation polymerization. 

Tables 1.1 and 1.2 illustrate some common chain-growth and step-growth polymers as well as monomers used in their preparations.

Table 1.2 Illustration of some step-growth polymers and monomers used in their preparation PoIy(ethyIene terephthalate)...

The properties of polymers formed by the step growth esterification (1) of glycols and dibasic acids can be manipulated widely by the choice of coreactant raw materials (Table 1) (2). The reactivity fundamental to the majority of commercial resins is derived from maleic anhydride [108-31-6] (MAN) as the unsaturated component in the polymer, and styrene as the coreactant monomer. Propylene glycol [57-55-6] (PG) is the principal glycol used in most compositions, and (i9f2v (9)-phthahc anhydride (PA) is the principal dibasic acid incorporated to moderate the reactivity and performance of the final resins. 

Table 2.3 Polymers Formed via Step Growth Polymerization and Their Reaction Mechanisms ...

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