Condensation polymerization derivatives

The diacids are characterized by two carboxyHc acid groups attached to a linear or branched hydrocarbon chain. AUphatic, linear dicarboxyhc acids of the general formula HOOC(CH2) COOH, and branched dicarboxyhc acids are the subject of this article. The more common aUphatic diacids (oxaUc, malonic, succinic, and adipic) as weU as the common unsaturated diacids (maleic acid, fumaric acid), the dimer acids (qv), and the aromatic diacids (phthaUc acids) are not discussed here (see Adipic acid Maleic anhydride, maleic acid, and fumaric acid Malonic acid and derivatives Oxalic acid Phthalic acid and OTHERBENZENE-POLYCARBOXYLIC ACIDS SucciNic ACID AND SUCCINIC ANHYDRIDE). The bihinctionahty of the diacids makes them versatile materials, ideally suited for a variety of condensation polymerization reactions. Several diacids are commercially important chemicals that are produced in multimillion kg quantities and find appHcation in a myriad of uses. 

The chemical and physical properties of the polymers obtained by these alternate methods are identical, except insofar as they are affected by differences in molecular weight. In order to avoid the confusion which would result if classification of the products were to be based on the method of synthesis actually employed in each case, it has been proposed that the substance be referred to as a condensation polymer in such instances, irrespective of whether a condensation or an addition polymerization process was used in its preparation. The cyclic compound is after all a condensation product of one or more bifunctional compounds, and in this sense the linear polymer obtained from the cyclic intermediate can be regarded as the polymeric derivative of the bifunctional monomer(s). Furthermore, each of the polymers listed in Table III may be degraded to bifunctional monomers differing in composition from the structural unit, although such degradation of polyethylene oxide and the polythioether may be difficult. Apart from the demands of any particular definition, it is clearly desirable to include all of these substances among the condensation... 

Polycarbonates. The polycarbonates surfaced in the 1950s, so they are middle-aged polymers. They are made in a condensation polymerization process. The reactants are either Bisphenol A and phosgene or Bisphenol A, phosgene, and phenol. Since Bisphenol A is a derivative of phenol, the building block is the same in either case—phenol. The polycarbonate based on Bisphenol A has the best balance of properties. If you look hard, you can see the monomers in Figure 24—7. ... 

While dicarboxylic acid-functional pyrroles have received only cursory attention in condensation polymerizations, other derivatives have been studied extensively. Pyrrole itself has been electrooxidatively polymerized (81CS145) to give a flexible conductive film, presumably containing poly(2,5-pyrrolediyl) units (23) as the main structural feature. The blue-black polymer obviously contains other functionality, as evidenced by elemental analysis and by the fact that it carries a partial positive charge, and it exhibits p-type conductivities approaching the metallic range (e.g. 100 fi-1 cm-1). The main utility of poly(pyrrole) (23) has been for the modification of electrode surfaces, although numerous other applications can be envisioned. 

Before discussing the various methods used to achieve condensation polymerization of sugars and sugar derivatives, several factors will be... 

First, condensation polymerization of sugars and their derivatives is an equilibrium process (see, for example, equation 2), a nearly stoichiometric... 

A major undertaking was initiated in 1950 by Pacsu and Mora,104 and later continued by Mora and colleagues, to establish optimal conditions for the condensation polymerization of simple sugars, both mono- and disaccharides. These studies also involved the preparation of derivatives of polyglucose [containing —CO H, —OSO H, —0N02, —0—CHjCHjNH, ... 

Several polyamides and polyurethanes have been synthesized by condensation polymerization and used as the precursors for the preparation of different CSPs. These CSPs showed different chiral recognition properties than those of addition polymers. AUenmark and Andersson [67] prepared a CSP containing silica gel supported by v-triazinc derivatives of L-valine isopropyl esters (Fig. 14) and the... 

In many respects, the polyphosphazenes are the prototype inorganic backbone polymers, that exemplify the principles of ring-opening and condensation polymerization, macromolecular substitution reactions and their potential for molecular design, and an enormous range of derivatives with the same backbone but different organic side groups. 

Another approach to block copolymers of the aromatic polyamide and coil polymer is the macroinitiator method the chain-growth condensation polymerization of 22a from a macroinitiator derived from coil polymer. A diblock... 

Polylactide is a degradable polyester, formed by the ring-opening polymerization of lactide or the condensation polymerization of lactic acid. Lactide is produced from lactic acid, which derives from the fermentation of D-glucose, which is usually harvested from high-starch-content crops, such as com or sugar beet (Fig. 1). 

Finally, two other polymers may be mentioned in this chapter which are formed by poly condensation of known active substances. A polymeric derivative of fluoro-uracil with the following formula 36, synthesized by Schmahl and his co-workers (104), showed an improved and extended activity in comparison with the low molecular substance, whereas no activity has been observed by Goodman and his coworkers (105) for a peptide-like polymer of sarcolysin. 

While all substituted di-p-xylylenes are pyrolyzed under substantially identical conditions, the temperatures of condensation and polymerization varied substantially, depending on the p-xylylene derivative under study. It was established that there is a threshold condensation temperature, Tc, above which the rate of condensation-polymerization was very slow under the system conditions (50-100 fi) normally used. The Tcs for several p-xylylene monomers were established as follows ... 

Most pertinent examples are mentioned in the review by Clouet et al. [12] and various monomers were utilized as macroprecursors styrene, MMA, alkyl acrylates, and isoprene. The synthesis of triblock copolymers can be easily achieved by condensation of these macroprecursors with monofunctional polymeric derivatives as shown in the following characteristic example [226] ... 

Polysaccharides are naturally occurring polymers, which can be considered as derived from aldoses or ketoses by condensation polymerization. A polysaccharide derived from hexoses, for example, has the general formula (C6H]oOs)n. This formula, of course, tells us very little about the structure of the polysaccharide. We need to know what the monosaccharide units are and how many there are in each molecule how they are joined to each other and whether the huge molecules thus formed are straight-chained or branched, looped or coiled. 

Substitution at the vinylic carbons can also be used to alter the electronic properties. For example, the substitution of electronegative -CN groups has been found to increase the electron affinity and ionization potential of PPV derivatives, thus improving the electron-injection characteristics.35,36 The synthesis is performed by the Knovenagel condensation polymerization of a terephthaldehyde and a benzene-1,4-diacetonitrile derivative, as shown in Fig. 5.10. 

While ring-opening polymerization shares certain features with condensation and addition polymerization mechanisms, it differs from each of them in at least one important respect. In the first place, in contrast to condensation polymerization, no small molecule is split off in ring-opening polymerization. Second, unlike olefin polymerization, the driving force for ring-opening polymerization is not derived from the loss of unsaturation. 

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