Classification of polymerization

TABLE 13.6 Classification of Polymerization Mechanisms that Use Water as the Continuous, Suspending Phase... 

The study of the molecular weight of the intermediate course is an effective method for the classification of polymerization as chain or stepwise reaction. In Figure 3, the molecular weight of the obtained polymer is plotted against the yield, for the oxidative polymerization of dimethylphenol with the copper catalyst and for the electro-oxidative polymerization. The molecular weight rises sharply in the last stage of the reaction for the copper-catalyzed polymerization. This behavior is explained by a stepwise growth mechanism. 

The rapid classification of polymeric species is an important problem in the area of analytical chemistry in general and of particular relevance to recycling and waste management. To accomplish classification tasks, a combination of spectral data and principal component analysis (PCA) is often employed. 

The proceeding classification of polymerization reactions concentrates essentially on the organic chemical character of the involved monomers... 

SCHEME 2.1 Classification of polymeric liquid crystals0 Classes of polymeric... 

The rate of polymeric chain generation used to help in the classification of polymerization processes, and to this day chain polymerizations and step polyadditions are distinguished. This classification was introduced long ago and is mainly based on the observation that the molar mass of the product is sometines roughly independent of time (conversion) whereas in other cases it increases considerably. Strictly speaking, every polymerization is a chain polymerization and, at the same time, each is a polyaddition. 

The number of monomers and the manner of their alternation in the polymer permits the classification of polymerizations as homopolymerization and copolymerization. 

The first section of this chapter describes the solution properties of polymers, and this is followed by a general classification of polymeric surfactants. Examples are provided of polymeric surfactants and polyelectrolytes that are used as dispersants and emulsifiers. 

Origin Another possible classification of polymeric substances can be based on the origin of the material or the repeating units. In this sense, one can have natural and synthetic polymers, if they occur in nature or if they are synthesized in a chemical laboratory, respectively. Of course, natural polymers are of great importance, but they fall out of the scope of this handbook, which is mainly concerned with synthetic polymers. 

Table 5.2 gives a simple classification of the possible types of motion, but it must be recognised at the outset that, just as the classification of polymeric material into two sharply defined categories of crystalline or amorphous is an approximation, so is the classification of motions into discrete types. Nevertheless, this approach is useful for developing models with which to correlate observations made by using different techniques. 

Table 6 Classification of polymeric foams and foaming processes [35-40]...

Figure 1-1 Classification of polymeric materials names each of these groups and also quotes examples.

Bajpai and coworkers (2008) reported a classification of polymeric DDS according to the mechanism controlling the drug release (Peppas and Khare 1993), as follows. 

The three tables embody a certain classification of polymerization reactions similar to that of the much simpler division of ordinary gas reactions into mono-, bi- and tri-molecular. However, through the inevitable overlapping of the three component reactions described, the conditions prove more complex and the systematization of polymerization reactions is less simple. 

Rubber is material with important applications in different areas, highlighting the automotive area, due to chemical and physical property, especially their stmcture composition, this material is considered an elastomer within the classification of polymeric materials. 

In this overview, the first section will on general classification of polymeric surfactants. This is followed by a section on preparation of polymeric snrfactants, with particular reference to sugar-based molecules. This is followed by a discussion of their solntion properties. The next section will be devoted to the adsorption of polymeric snrfactants at the solid/liquid (S/L) interface, whereby a summary will be given to some of the theoretical treatments and the methods that... 

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