Part II Condensation Polymers

In the last section we examined some of the categories into which polymers can be classified. Various aspects of molecular structure were used as the basis for classification in that section. Next we shall consider the chemical reactions that produce the molecules as a basis for classification. The objective of this discussion is simply to provide some orientation and to introduce some typical polymers. For this purpose a number of polymers may be classified as either addition or condensation polymers. Each of these classes of polymers are discussed in detail in Part II of this book, specifically Chaps. 5 and 6 for condensation and addition, respectively. Even though these categories are based on the reactions which produce the polymers, it should not be inferred that only two types of polymerization reactions exist. We have to start somewhere, and these two important categories are the usual place to begin. 

Costa, L. Camino, G. Luda, M. P. Mechanism of condensed phase action in fire retardant bismuth compound-chloroparaffin-polypropylene mixtures Part II—The thermal degradation behavior, Polymer Degradation and Stability, 1986, 14(2), 165-177. 

Condensation polymers described in Part II are classified as polyesters, polyamides, formaldehyde resins, polyurethanes, and ether polymers. 

Kleideiter G, Nordmeier E (1999) Poly(ethylene glycol)-induced DNA condensation in aqueous/methanol containing low-molecular-weight electrolyte solutions. Part II. Comparison between experiment and theory. Polymer 40 4025 033... 

Ravey, M. Weil, E.D. Keidar, I. Pearce, E.M. Flexible polymethane foam. II. Fire retardation by tris(l,3-dichloro-2-propyl) phosphate. Part B. Examination of the condensed phase (the pyrolysis zone). J. Appl. Polym. Sci. 1998, 68, 231-254. 

Finally, the multiple reflection IR spectra, obtained on the mono-molecular films from solvent II and transferred at constant pressure in the zone of condensed film, are shown in Figure 4, part 2. The band at 1630 cm"1 is characteristic of the ft form (33, 39). Thus, the surface contains two-dimensional films of ft helixes in the case of pyridine-rich spreading solvents. This agrees with the results of others for different polymers (33). The f3 helixes for the same polymer in monolayer are present (40) because the sample had a low molecular weight. 

Knani, D., Gutman, A.L., and Kohn, D.H. (1993) Enzymatic polyesterification in organic media. Enzyme-catalyzed synthesis of linear polyesters. I. Condensation polymerization of linear hydroxyesters. II. Ring-opening polymerization of e-caprolactone. J. Polym. Sci. Part A Polym. Chem., 31 (5), 1221-1232. 

T. Yokozawa and H. Shimura. Condensative chain polymerization. II. Preferential esterification of propagating end group in Pd-catalyzed CO-insertion polycondensation of 4-bromophenols derivatives. J. Polym. ScL, Part A Polym. Chem. 37(14), 2607-2618 (1999). 

Hagihara and coworkers in the 1970 s and early 1980 s have reported a successftil condensation polymerization strategy to incorporate late second- and third-row transition metal ions (mainly Pt(II) and Pd(II)) as part of a polymeric linear chain [65-67]. Since these metal ions prefer square-planar geometric structures, they designed compounds that contained two reactive chlorine groups in a trans orientation. Condensation of such di-fimctional monomers with traw -diacetylides afforded linear polymers which are calledpolyynes (Fig. 8.32). 

Chapters 10-12 are three chapters that address special areas of interpretation. Chapter 10 is focused on the interpretation of polymer spectra. Exercise Sections 1 and II have three exercises that involve the identification of relatively simple polymer spectra. These spectra were introduced to demonstrate to the reader that the extension of the group frequencies approach to the interpretation of polymer spectra is, in general, straightforward. However because of the importance of polymer spectra, we now consider this area in some detail in Chapter 10. Section I of the chapter builds on the interpretation of the spectra of hydrocarbon polymers started in exercise sections I and II. In section II the problem of the presence of plasticizers is examined and in addition the polymerization of hetero-atom monomers is explored. The sampling of polymers to acquire infrared and Raman spectra often requires specialized techniques. A short introduction to a few of these techniques is given in Section III. The chemistry involved in the formation of polymers is reviewed in part IV with examples of condensation (nylon) and addition (polyethylene) polymerization presented. Copolymers are examined next (V) with methylmethacrylate-stryene used as an example. The effects on the spectra of block and random copolymerization are also noted. Next crosslinked polymerization is studied (VI) with phenol-formaldehyde. Tacticity (VII) is then explored with evidence for its presence in the spectra of polypropylene. This discussion leads to a concise examination of conformational isomerism (VIII) and the impact of this... 

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