Polymerization classification

Synonyms 1,2-Dihydro-2,2,4-trimethylquinoline homopolymer 1,2-Dihydro-2,2,4-trimethylquinoline polymer Poly-(1,2-dihydro-2,2,4-trimethylquinoline) Polymerized 1,2-dihydro-2,4,4-trimethyl quinoline Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline TDQP TMDHQ TMQ Trimethyidihydroquinoline polymer 2,2,4-Trimethyl-1,2-dihydro-quinoline, polymeric Classification Dihydroquinoline Empirical (C H, N) ... 

Synonyms 1,1,2,3,3,3-Hexafluoro-1 -propene, oxidized, polymerized 1-Propene, 1,1,2,3,3,3-hexafluoro-, oxidized, polymerized Classification Fluorine-based polymer Formula CF3(OCF3CFCF2)x(OCF2)yOCF3 Toxicology TSCA listed Uses Lubricant, emollient in cosmetics Trade Name Synonyms Fomblin HC/01 [Solvay Solexi s http //www.solvaysolexis. com] Fomblin HC/02 [Solvay Solexis http //www.solvaysolexis. com], Fom bli n HC/03 [Soivay Solexis http //www.solvaysolexis. com] Fom bli n HC/04 [Soivay Soiexis http //www.solvaysolexis.com]-, Fomblin HC/25 [Soivay Soiexis http //www.solvaysolexis. com]... 

Polysodium vinyl sulfonate Synonyms PSVS Sodium vinyl sulfonate polymerized Classification Polymer Definition Polymer of sodium vinyl sulfonate Properties M.w. 10,000 Uses As dispersant and deflocculant for calcium carbonate and other pigment slurries used in paints, coatings, inks, and paper coatings in paper/paperboard in contact with aq./fatty foods... 

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. 

The limiting oxygen index of Tefzel as measured by the candle test (ASTM D2863) is 30%. Tefzel is rated 94 V-0 by Underwriters Laboratories, Inc., in their burning test classification for polymeric materials. As a fuel, it has a comparatively low rating. Its heat of combustion is 13.7 MJ/kg (32,500 kcal/kg) compared to 14.9 MJ /kg (35,000 kcal/kg) for poly(vinyHdene fluoride) and 46.5 MJ /kg (110,000 kcal/kg) for polyethylene. 

Condensed phosphates are derived by dehydration of acid orthophosphates. The resulting polymeric stmctures are based on a backbone of P—O—P linkages where PO tetrahedra are joined by shared oxygen atoms. The range of materials within this classification is extremely broad, extending from the simple diphosphate, also known as pyrophosphate, to indefinitely long-chain polyphosphates and ultraphosphates (see Table 1). Both weU-defined crystalline and amorphous materials occur among the condensed phosphates. 

Adsorption of dispersants at the soHd—Hquid interface from solution is normally measured by changes in the concentration of the dispersant after adsorption has occurred, and plotted as an adsorption isotherm. A classification system of adsorption isotherms has been developed to identify the mechanisms that may be operating, such as monolayer vs multilayer adsorption, and chemisorption vs physical adsorption (8). For moderate to high mol wt polymeric dispersants, the low energy (equiUbrium) configurations of the adsorbed layer are typically about 3—30 nm thick. Normally, the adsorption is monolayer, since the thickness of the first layer significantly reduces attraction for a second layer, unless the polymer is very low mol wt or adsorbs by being nearly immiscible with the solvent. 

Each of the PLgel individual pore sizes is produced hy suspension polymerization, which yields a fairly diverse range of particle sizes. For optimum performance in a chromatographic column the particle size distribution of the beads should be narrow this is achieved by air classification after the cross-linked beads have been washed and dried thoroughly. Similarly, for consistent column performance, the particle size distribution is critical and is another quality control aspect where both the median particle size and the width of the distribution are specified. The efficiency of the packed column is extremely sensitive to the median particle size, as predicted by the van Deemter equation (4), whereas the width of the particle size distribution can affect column operating pressure and packed bed stability. 

Structural classifications of oxides recognize discrete molecular species and structures which are polymeric in one or more dimensions leading to chains, layers, and ultimately, to three-dimensional networks. Some typical examples are in Table 14.14 structural details are given elsewhere under each individual element. The type of structure adopted in any particular case depends (obviously) not only on the... 

After a temptative structure-based classification of different kinds of polymorphism, a description of possible crystallization and interconversion conditions is presented. The influence on the polymorphic behavior of comonomeric units and of a second polymeric component in miscible blends is described for some polymer systems. It is also shown that other characterization techniques, besides diffraction techniques, can be useful in the study of polymorphism in polymers. Finally, some effects of polymorphism on the properties of polymeric materials are discussed. 

Anionic polymerization techniques can also be applied to the synthesis of graft copolymers 6 7 87 1U). Kennedy s classification 134) is used here as shown in Scheme 5. 

Classification of Processes and Reactors. Most styrene polymers are produced by batch suspension or continuous mass processes. Some are produced by batch mass processes. Mass in this sense includes bulk polymerization of the polymer... 

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

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... 

A corresponding anionic mechanism in the presence of a strong base (or electron donor) is plausible. Other cyclic compounds may be susceptible to polymerization by similar ionic mechanisms. Inasmuch as the growth step must be extremely rapid, a chain reaction is indicated and classification with vinyl-type addition polymerizations should be appropriate in such cases. 

The hazards of a rigid classification of substances which may modify the course of a free radical polymerization are well illustrated by the examples of inhibitors and retarders which have been cited. The distinction between an inhibitor or retarder, on the one hand, and a co-monomer or a transfer agent, on the other, is not sharply defined. Moreover, if the substance is a free radical, it is potentially either an initiator or an inhibitor, and it may perform both functions as in the case of triphenylmethyl. If the substance with which the chain radicals react is a molecule rather than a radical, three possibilities may arise (i) The adduct radicals may be completely unreactive toward monomer. They must then disappear ultimately through mutual interaction, and we have a clear-cut case of either inhibition or retarda-... 

Beyond N=9, y, (C) becomes higher than y (A). In general, the relative classification of the studied polymers hyperpolarizabilities does not follow the increase in the number of K electrons. An explanation can be found, if we consider the two important factors which are the lengthening of the polymeric chain and bond alternation. In Table 7, are given the MNDO optimized lengths L, of the studied oligomers. The variation of L as a function of N, is plotted in Figure 6. We can see that for any N value, we have approximately the classification ... 

Thermotropic liquid crystals may be classified as either low molar mass (i.e. non-polymeric), or high molar mass (i.e. polymeric) and within each of these broad classifications, there are several sub-classifications. 

---