Polymer structure general formula

IF the product were a monomer, its structure could be drawn as Cl2PsN, which is analogous to organic nitriles. R—C=N. For this reason the original names used for these compounds were phosphonitriles, phosphonitrilic chloride, etc. However, the products are actually either cyclic or linear polymers of general formula [NPC ,] . Thus, by analogy with benzene, borazine. etc., these compounds hove become known as phosphazenes. The rn jor product of the reaction in Eq. 16.47 and the easiest to... 

Structurally related to PEI is a family of synthetic polymers having general formula ... 

The term amorphous silica encompasses an almost infinite variety of structural forms, from ordered opaline aggregates to extended gel-like materials. In all these structures, the mineral exists as a hydrated, covalent inorganic polymer of general formula [SiO /2 (OH)4- ]m 4). This formula, where n = 0 to 4 and m is a large number, indicates the variation in residual functional groups within the condensed structure. There is similar variation in the extent of hydration. This flexibility in composition and reactivity indicates that biogenic silica is not a stoichiometric mineral (in the way that CaCOs is, for example) and that the nature (density, hardness, solubility, viscosity) and composition of siliceous structures in biology may vary consid-... 

The diversity of chemical structures in the polymer chains is characterized by the incorporation of eleven different chemical elements. Each polymer is identified by its chemical name. Chemical Abstracts Service Registry Number, synonym or commercial (trade) name, source, sample form (including the sample-preparation technique for IR measurements), representative molecular structure, general formula, comments, filenames of individual compounds spectra, and the entry numbers in our database. 

The most known and investigated substrate of this class is poly[bis(trifluo-roethoxy)phosphazene], PTFEP, a polymer formally derived by the general formula above by putting x=y=l and Z=R The general structure of this compound is shown below. 

AE and AP surfactants are synthesised by polymerisation of monomeric or short chain oligomeric glycol moieties. If mixtures of ethylene and propylene glycols, however, were applied for the synthesis, so called EO/PO block polymers in the form of complex mixtures with the general formula R-0-(E0)m-(P0) -H and the structure as shown with their... 

Isocyanates are compounds with the general formula R-N=C=0. They have numerous uses in chemical synthesis, particularly in the manufacture of polymers with carefully tuned specialty properties. Methyl isocyanate is a raw material in the manufacture of carbaryl insecticide. Methyl isocyanate (like other isocyanates) can be synthesized by the reaction of a primary amine with phosgene in a moderately complex process, represented by reaction 15.8.1. Structures of three significant isocyanates are given in Figure 15.7. 

The situation looks more complicated for polymers with mesogenic groups in the side chain, but in fact it is rather simple too. All these polymers can be represented by a general structural formula structure I in Fig. 6.17. This structure can immediately be derived from the general structure of comb-polymers (structure II in Fig. 6.17) the SCLCP is a comb-polymer with an... 

Polysilsesquioxanes of general formula R-[SiOj ] n=l are generally prepared by hydrolysis/polycondensation of the corresponding precursors RSiX (X=Q, OR, H). Four basic structures can be envisaged molecular compound with a cage stmcture, polymer with a regular ladder stmcture, polymer with a 3-D disordered structure and lamellar sohd. 

Table 2. Assignment of the polysilane resonances to structural groups, resulting in a general formula for the polymer Cl2CH3Si-[(CH3)SlR]x-SiCH3Cl2 R = Cl, S1CH3R2...

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