Polymer chemical combinations

Polymerisation involves the chemical combination of a number of identical or similar molecules to form a complex molecule. The resulting polymer has a high molecular weight. The term synthetic polymer is usually employed to denote these compounds of very high molecular weight. 

Cross-linked PVP can also be obtained by cross-linking the preformed polymer chemically (with persulfates, hydrazine, or peroxides) or with actinic radiation (63). This approach requires a source of free radicals capable of hydrogen abstraction from one or another of the labile hydrogens attached alpha to the pyrrohdone carbonyl or lactam nitrogen. The subsequently formed PVP radical can combine with another such radical to form a cross-link or undergo side reactions such as scission or cyclization (64,65), thus ... 

As already shown, it is technically possible to incorporate additive functional groups within the structure of a polymer itself, thus dispensing with easily extractable small-molecular additives. However, the various attempts of incorporation of additive functionalities into the polymer chain, by copolymerisation or free radical initiated grafting, have not yet led to widespread practical use, mainly for economical reasons. Many macromolecular stabiliser-functionalised systems and reactive stabiliser-functionalised monomers have been described (cf. ref. [576]). Examples are bound-in chromophores, e.g. the benzotriazole moiety incorporated into polymers [577,578], but also copolymerisation with special monomers containing an inhibitor structural unit, leading to the incorporation of the antioxidant into the polymer chain. Copolymers of styrene and benzophenone-type UV stabilisers have been described [579]. Chemical combination of an antioxidant with the polymer leads to a high degree of resistance to (oil) extraction. 

These enhance the appearance of the polymer, but play no role in the chemical, physical or mechanical properties of the base polymer. The main difficulty is that if the finished assembled article is made from different grades of the same polymer or from different polymers, then, particularly with different polymers, the combination must be uniform. For example, bathroom suites are often made from different materials, e.g., ceramics, baths (polyacrylates), trimmings (PVC, PP). The colorants therefore have to undergo different processing conditions and it is essential that in the final products the colour is the same. 

Besides the aforementioned, preliminary investigations showed that synthesized oligomers and polymers, in combination with phenolformaldehyde resin, were successfully used as binding component for polymer/graphite electro-conducting composites (ECC) [15, 16], Obtained ECC were recommended for creation of electrode material for electrolytic section and the chemical (fuel) sources of electrical energy (on the basis of analogous material) [16],... 

Polymers result from polymerization—the chemical combination of a large number of molecules of a certain type, called monomers. Monomers can be bifunctional (capable of joining up with two other monomers) and tri- or polyfunctional (each may join up with three or more monomers). When bifunctional monomers react with each other, you get linear thermoplastic... 

Han [17] has shown that the effect of silane coupling agents on the viscosity of filled thermoplastics is not consistent. Melt viscosity may be decreased or increased depending on the chemical structure of the treatment and the nature of the polymer/filler combination under consideration. These observations probably reflect the effectiveness of the coupling agent in promoting bonding between filler and polymer, and hence the extent of polymer immobilization. 

Polymer A macromolecular material formed by the chemical combination of monomers having either the same or different chemical composition. 

Polybrominated Diphenyl Ethers. PBDEs are used as additive flame retardants in thermoplastics. Additive flame retardants are physically combined with the polymer material being treated rather than chemically combined (as in reactive flame retardants). This means that there is a possibility that the flame retardant may diffuse out of the treated material to some extent. 

The chemical treatment employed is a combination/derivation of an Alkaline Zinc Polymer Program and a Stabilized Phosphate Program. It operates at an alkaline pH and uses zinc to synergize with phosphate to enhance corrosion protection and reduce the amount of PO4 required (this is Chemical 1). It requires a PO4 stabilizer polymer (Chemical 2). 

We also note that carboxylate ions which are chemically combined at the polymer-water Interface are known to be considerably more effective in conferring mechanical stability upon a latex than are carboxylate ions which are held at the interface by adsorption. Presumably this is because the latter are able to move laterally in the particle surface, whereas the former are not.) We propose that a given number of adsorbed soap anions is more effective in conferring mechanical stability if able to move independently of... 

Of all the elements, fluorine is the most reactive and the most electronegative (a measure of tendency to acquire electrons). In its chemically combined form, it always has an oxidation number of -1. Fluorine has numerous industrial uses, such as the manufacture of UF6, a gas used to enrich uranium in its fissionable isotope, uranium-235. Fluorine is used to manufacture uranium hexafluoride, SF6, a dielectric material contained in some electrical and electronic apparatus. A number of organic compounds contain fluorine, particularly the chlorofluorocarbons used as refrigerants and organofluorine polymers, such as DuPont s Teflon. 

The work described here supports the view that the chemical combination of metal ions with organic molecules leads to coordination complexes and polymers with enhanced stability with respect to weight loss, thermal degradation, or oxidation. Bis(8-hydroxyquinoline) derivatives were used to prepare a series of coordination polymers containing first-row transition metals, and the thermal stabilities of the polymers were evaluated. The influence of the structure of the organic molecule and the role of the metal are discussed. 

This nomenclature primarily answers three questions about the chemical entity (1) which polymers are combined, (2) principal modes of combination, and (3) the time sequence of reaction. Other items of information, such as weight proportions, molecular weights, morphology, tacticity, etc. can be included as ancillary items but will not be discussed in detail below. 

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