Classifications polymer type

Classification Polymer Definition A type of epoxy resin made from bisphenol A and epichlorohydrin Empirical (Ci8H2iCI03)n Formula (C15H16O2 C3H5CIO)n Properties M.w. (320.82)n Toxicology LD50 (oral, rat) 1100 mg/kg, (skin, rabbit) > 20 ml/kg mod. toxic by ing. and skin contact... 

With these guides, it becomes necessary to study and analyze the crystallization and gelation of several different polymer types, in each of the categories, in order to determine the basic principles involved in gel mechanism and in establishing gel properties. The classification in Figure 1 serves as a basis for which diverse experiments that have been reported can be analyzed in a unified manner and as a direction for new experiments with specifically chosen model systems. It makes clear the extreme importance of determining the microstructure of the chain, particularly whether it possesses any copolymeric character, and also establishing the thermodynamic nature of the polymer-solvent system. 

Figure 1.9 Classification of morphology by the chemical structural polymer type.

Table 1 Polymer type classification based on photochemical behavior [after J. Lemaire, Report PB90-2002482, NTIS, 1990] ...

Classifying shape memory polymers classification by type of stimulus... 

Fibrous reinforced composites are sometimes classified according to matrix type within this scheme are three classifications polymer-, metal-, and ceramic-matrix composites. 

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. 

This second classification is not rigorous since often the polymer structure is not defined by only one type of repeat unit and the furan ring is encountered both in the backbone and as a side group. However, it is felt that the practical convenience of this classification outweight its minor inconsistencies. 

There is an extremely wide range of potentially useful chemical treatments available, and for any boiler system, proper selection, utilization, and control are vital considerations that may largely determine the ultimate success of the overall program. These chemicals usually are organized by type of compound, function, mode of action, or similar classification, but, because many chemicals are multifunctional in character, may be used in either a primary or supplementary (adjunct or conjunctional treatment) role, and additionally may be branded (especially many modem polymers) or otherwise disguised, such classifications may be quite arbitrary. 

Table 1. Classification of different types of monomers for synthesis of hyperbranched polymers...

The A-B type iniferters are more useful than the B-B type for the more efficient synthesis of polymers with controlled structure The functionality of the iniferters can be controlled by changing the number of the A-B bond introduced into an iniferter molecule, for example, B-A-B as the bifunctional iniferter. Detailed classification and application of the iniferters having DC groups are summarized in Table 1. In Eqs. (9)—(11), 6 and 7 serve as the monofunctional iniferters, 9 and 10 as the monofunctional polymeric iniferters, and 8 and 11 as the bifunctional iniferters. Tetrafunctional and polyfunctional iniferters and gel-iniferters are used for the synthesis of star polymers, graft copolymers, and multiblock copolymers, respectively (see Sect. 5). When a polymer implying DC moieties in the main chain is used, a multifunctional polymeric iniferter can be prepared (Eqs. 15 and 16), which is further applied to the synthesis of multiblock copolymers. 

In more recent years, Herman Mark has, as we all know, concentrated more on the effects of heterophase morphology of polymers on their mechanical properties. This has enabled him to set up a useful classification system of the various types of heterogeneities which can occur in polymers, e.g., crystallinity, incompatibility, particulate and fibrous inclusions, etc. and to discuss these in the context of their effect on the mechanical properties. Such an "overview" has again kept Mark in great demand as a speaker. 

Different classifications for the chiral CSPs have been described. They are based on the chemical structure of the chiral selectors and on the chiral recognition mechanism involved. In this chapter we will use a classification based mainly on the chemical structure of the selectors. The selectors are classified in three groups (i) CSPs with low-molecular-weight selectors, such as Pirkle type CSPs, ionic and ligand exchange CSPs, (ii) CSPs with macrocyclic selectors, such as CDs, crown-ethers and macrocyclic antibiotics, and (iii) CSPs with macromolecular selectors, such as polysaccharides, synthetic polymers, molecular imprinted polymers and proteins. These different types of CSPs, frequently used for the analysis of chiral pharmaceuticals, are discussed in more detail later. 

The features common to reversible polymer gels of many types are identified suid discussed. The nature of the gel state is carefully defined, and a novel classification scheme based on morphology, rather than chemical or mechanistic considerations, is proposed. The article also serves as an overview to some of the more commonly used techniques used in the study of gels, and as an introduction to some of the current trends in reversible gel research. Some speculations regarding future trends in reversible gel research are presented. 

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