High-temperature polycondensation

Diamino-6-(N-phthalimido)-toluene was reacted with aromatic tetracarboxylic acids, 3,3, 4,4 -tetracarboxydiphenyl ether, 3,3, 4,4 -tetracarboxybenzophenone and dianhydrides, dianhydride 6F and dianhydride A, using high-temperature polycondensation in w-cresol with quinoline as a catalyst (Scheme 5.8). 

Hereinafter, second values of viscosity are obtained by high-temperature polycondensation of 1,5-dihydroxyorganocyclohexasiloxanes with a,co-bis(dimethylamino)dimethylsiloxanes. For these samples, viscosities in benzene are determined. 

Pyrolysis or high-temperature polycondensation of polymers or polyfunctional monomers yielded new types of intrinsically conductive polymers and high-quality graphite which can be classified as lowdimensional graphites. 

These two ways of receiving block-copolymers may be realised by acceptor- catalytic, emulsive and high-temperature polycondensation. 

Oligoketons, oligosulphoneketons, oligosulphones of different level of condensation were synthesized by method of high temperature polycondensation in the aprotonic dipolar solvent medium in the atmosphere of inert gase. 4,4 - dioxydiphenylpropans, phenolphthalein, 4,4 dichlordiphenylsulphon, 4,4/-dichlorbenzophenon were used as initial materials. 

These reactions have b n carried out both under traditional conditions, i.e. high-temperature polycondensation in m-cresol and application of benzoic acid as catalyst [99] and in a ries of other solvents [190] - mixtures of m-cresol and polyphosphoric acid, m-cresol and di-m-cresyl phosphate, m-cresol... 

Synthesis of these polynaphthoylenebenzimidazoles was carried out by the high temperature polycondensation technique in m-cresol using benzoic add as catalyst. All reactions for synthesis of polynaphthoylenebenzimidazoles ran homogeneously and led to well-cyclized high molecular polymers. Some characteristics of polynaphthoylenebenzimidazoles based on a series of aroylene-bis(naphthalic anhydrides) and 3,3, 4,4 -tetraaminodiphenyl oxide are shown in Table 23. 

In interfacial polymerization a pair of immiscible liquids is employed, one of which is usually water while the other is a hydrocarbon or chlorinated hydrocarbon such as hexane, xylene, or carbon tetrachloride. The aqueous phase contains the diamine, diol, or other active hydrogen compound and the acid receptor or base (e.g., NaOH). The organic phase, on the other hand, eontains the acid chloride. As the name suggests, this type of polymerization occurs interfacially between the two Hquids. In contrast to high-temperature polycondensation reactions, these reactions are irreversible because there are no significant reactions between the polymer product and the low-molecular-weight by-product at the low... 

PNI with bulky N-naphthalenecarboximide ortho substituents, synthesised from bis[3-amino-4-(p-aminophenoxy]arylenes [66] were allowed to react first with DNTA and then with a two-fold molar amount of naphthalic anhydride under the conditions ensuring high-temperature polycondensation (Scheme 1.13, method A). 

In Table 17 the comparison of different parameters for PAr on the basis of phenolphthaleine (F-2 according to the designation, accepted in Ref. [5]) for different solvents, in which Maik-Kuhn-Houwink parameters were determined. Firstly, 6 calculation according to the Eq. (18) of Chapter 1 gave these dimension values of 0.36-0.84 for F-2, received by equilibrium polycondensation, and 8 0—for received by interphase polycondensation. This means that the solvent molecules stmcture does not influenced (does not screened repulsive interactions) on F-2 macromolecular coil structure, received by interphase polycondensation, and influences on the similar factor for F-2, received by high-temperature polycondensation. In other words, if the solvent influences on formation of coil structure in synthesis process, then it will be influenced and on this polymer formed coil structure at subsequent... 

The data for high-temperature polycondensation of different disodium salts of the bisphenols with 4,4 -dichlorodiphenylsulfone (DCDPS) are used [47], The bisphenols denomination, their conventional signs and also the values of poly condensation rate constants k and En are adduced in Table 2. Besides, the kinetic curves conversion degree — reaction duration (Q -1) of polycondensation, adduced in the work [47], were used. 

In work [62] it has been shown, that temperature synthesis T increasing at high-temperature polycondensation of polyaiylates, obtained by interaction of diphenols of different chemical stracture with dianhydride of terephthalic acid, results to reaction rate constant growth (the value pj was used for polycondensation first stage up to conversion degree Q 0.30-0.50). The solvent nature, in solution of which synthesis was performed, influences perceptibly on value. So, the value - pj is higher at polycondensation in nitrobenzene enviromnent, than in diphenyloxide enviromnent. The systematic enhancement was found... 

Thus, the stated above results have shown, thatpolyarylates series high-temperature polycondensation kinetics, characterized by the reaction rate constant pi, at different temperatures and solvents is controlled by three main factors process thermal activation (T), diphenol reactiveness (Z r) and macromolecular coil stmc-ture (Dj.). The obtained generalized dependence Ig allows to perform... 

Let us note, that value of macromolecular coil in solution defines polymer stmcture in condensed state [74], For example, higher values for PAr, of the obtained high-temperature polycondensation, define higher fractal dimension of solid-state PAr [74] and, hence, higher values of fracture strain [75], that is confirmed experimentally [53],... 

In paper [67] it has been shown, that high-temperature polycondensation kinetics of polyaiylates and polysnlfones series, characterized by reaction rate constant kr (determined on the first initial part of the kinetic curve Q,) at different temperatures and reactive medinms is described by three main factors. These factors are Process thermal activation, bisphenols reactive ability and macromo-lecular coil structure. The indicated factors can be characterized quantitatively... 

Kozlov, G. V. Musaev, Yu. I. MUdtaev, A. K. Diffusion and chemically limited regimes of high-temperature polycondensation with bisphenols participation. Mater, of V International sci.-pract. conf. New Polymeric Composite Materials. Nal chik, KBSU, 2009,112-117. 

Obtained copoly and block-copolyestersulfoneketones, as well as polyaiylates based of dichloranhydrides of phthalic acids and chloranhy-dride of 3,5-dibromine- -oxybenzoic acid and copolyester with groups of terephthaloyl-bis(w-oxybenzoic) acid possess high mechanical and dielectric properties, thermal and fire resistance and also the chemical stability. The regularities of acceptor-catalyst method of polycondensation and high-temperature polycondensation when synthesizing named polymers have been studied and the relations between the composition, structure and properties of polymers obtained have been established. The synthesized here block-copolyesters and copolyesters can find application in various fields of modem industry (automobile, radioelectronic, electrotechnique, avia, electronic, chemical and others) as thermal resistant constmction and layered (film) materials. 

These pol5miers have been synthesized by high-temperature polycondensation of terephthaloyl-bis(n-oxybenzoylchloride) with appropriate diols in high-boiling dissolvent imder the pressure of inert gas. Bispheny-loxide is used as dissolvent. 

The synthesis of block-copolymer went in two stages. At first, the polyester block of required molecular weight was produced while on the second stage that block (without separation) reacted to the polysulfonic block. The synthesis was carried out by the method of high-temperature polycondensation in the solution at 250 °C in environment of a-chlomaphthalene. The duration of the first stage was 1.5 h, and the second stage was 1 h. Obtained polymers exhibited liquid-crystal properties. 

The block copolymers, containing units of polyarylesterketones and segments of thermotropic liquid-crystal polyesters of different length, are synthesized by means of high-temperature polycondensation in solution... 

Oligosulphoneketon, oligosulphone, oligoketon synthesis was conducted by means of high temperature polycondensation in aprotonic dipolar solvent medium - dimethylsulfoxide (DMSO) - within inert gas atmosphere (nitrogen). 

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