Polymer synthesis polycondensation

Various inorganic, organic, and organometaUic compounds are known to cataly2e this polymerization (4,8,9). Among these, BCl is a very effective catalyst, although proprietary catalysts that signiftcandy lower polymerization temperature from the usual, sealed-tube reaction at 250°C are involved in the industrial manufacture of the polymer. A polycondensation process has also been developed for the synthesis of (4) (10—12). This involves elimination of phosphoryl chloride from a monomer prepared from (NH 2 04 and PCl. ... 

L. B. Sokolov, Synthesis of Polymers by Polycondensation, Israel Program for Scientific Translation, Jemsalem, Israel, 1968, pp. 60—71. 

We examined several approaches for synthesizing polyanhydrides, including melt polycondensation, dehydrochlorination, and dehydrative coupling. Extensive details of these new polymer synthesis techniques and numerous polymerization conditions for a wide variety of polyanhydrides were previously described (1). 

Mikami, M. Shinkai, S. Synthesis of helical polymers by polycondensation of diboronic acid and chiral tetrols. Chem. Lett. 1995, 603-604. 

The synthesis of block copolycondensates by condensation reactions has also been described very often indeed the ineluctable presence of reactive end groups makes these molecules especially suitable for reactions with dibasic acids, diisocyanates, diacid chlorides, diamines, diols, etc. Using this method it was for example possible to synthesize polycondensates in which crystalline blocks alternate with amorphous blocks similarly it makes possible the synthesis of high molecular weight polymers from polycondensates of relatively low degree of polymerization. 

Sokolov, L. B., "Fundamentals of the Synthesis of Polymers by Polycondensation Method". Khimia, Moscow (1979). 

Scheme 2 describes the polymer synthesis involving polycondensation between monomer complexes, containing ligands with difunctional groups, and difunctional organic monomers. 

Nevertheless, the route is attractive, because many interesting ladder structures are not accessible using the polycondensation or polyaddition of multifunctional monomers [2, 5]. Besides the specific problems of ladder polymer synthesis discussed above, another problem is almost invariably associated with... 

A new quality in ladder polymer synthesis via multifunctional polycondensation was reached in the late 1960s when poly(benzimidazobenzo-phenanthroline) (BBL) 12 was prepared by Arnold and van Deusen [21 -24]. The polymer was synthesized from naphthalene-l,4,5,8-tetracarboxylic acid dianhydride (11) and 1,2,4,5-tetraaminobenzene (la) in strong acidic media (polyphosphoric acid, sulfuric acid). BBL is completely soluble in concentratal sulfuric acid or methanesulfonic add and is processible into durable films and... 

A wide range of carbonyl addition reactions is available to the polymer synthesis chemist. To the extent that reactants having functionalities of two or higher are available, these reactions may be suitable for polycondensation. A simplified scheme is... 

Several years ago, encouraged by the proven intermediacy of polyimidazolines in Gray s imidazole polymer synthesis we set out to demonstrate experimentally an analogous intermediary stage in the polycondensation of Scheme 13 and develop a preparative approach that would enable us to isolate soluble polyimidazoline intermediates. Clearly, if such polymeric imidazolines could be isolated and their further smc th conversion to polybenzimidazoles be accomplished, the door would be opened for the development of two-stage processing techniques involving prepolymer-type materials. Initial... 

Polycondensation methods for thermostable polymer synthesis 86MI12. Polyimides from heterocyclic monomers 80UK2418. 

Nomura, R. Watanabe, K. Masuda, T. Synthesis of metal-carbene containing polymers by polycondensation of a bifunctional alkoxycarbene with diamines. Macromolecules 2000, 33, 1936-1939. 

An important aspect of polymer synthesis is the use of different catalysts to facilitate polymerization and polycondensation. For example, in the... 

Hence, the stated above results have shown, that the main cause of different macromolecular coil structure of PAr with the same chemical stmcture, but obtained by different polycondensation modes, is participation (or imparticipation) of solvent molecules with 5 >0 in synthesis process. Obtained in this process coil stmcture maintains at subsequent polymer dilution and solvents influence in this case is similar to their influence in polymer synthesis process. Fractal analysis methods give mathematical apparatus for this problem quantitative study. 

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