Reaction interfacial polycondensation

The condensation polymerization process, employed recently by Skourlis et al. (1993) and Duvis et al. (1993), involves immersion of carbon fibers in a solution containing hexamethylenediamine and sodium carbonate. Dried carbon fibers are then immersed in a dipolychloride solution in carbon tetrachloride where the interfacial polycondensation reaction takes place. The result is that a thin layer of polyamide (nylon 6,6) coating is deposited on the continuous carbon fiber, whose thickness is controlled though by varying the diamine concentration. 

The suspension polymerization process allowed the formation of capsules of l-30 rm consisting of migrin oil as core and polyurea as wall material. The latter was formed by interfacial polycondensation reactions between different diisocyanates and emulsified ethylenediamine [106],... 

The class of phosphoester-based polymers includes polyphosphates, polyphosphonates, and polyphosphites (Table 8). A series of phosphoesters based on bisphenol A (BPA) have been prepared and evaluated in drug delivery applicationsJ Polymerization was carried out by interfacial polycondensation reaction of... 

These and other factors affecting the interfacial polycondensation reaction are discussed in more detail in P.W. Morgan s book entitled, Condensation Polymers published by Interscience Publishers, John Wiley Sons, 1965 [66]. 

Diacylation of an amine by the acid halide leads to branched and network polymers. This side reaction has also been observed in interfacial polycondensation reactions [70]. 

Figure 7.16 Design and synthesis of a chemically functional polymer membrane by an interfacial polycondensation reaction and multilayer flow inside a microchannel.

In the present study Ni ion is being absorbed. The adsorbent species (solid phase) are the three Group IVB products obtained from the interfacial polycondensation reaction between HPIX and the Group IVB metallocene dichlorides " and two commercially available ion exchange resins. Adsorption is the physical or chemical bonding to the surface. 

Scheme 24 summarizes the preparation of polyamides (99) and polyureas (101) from the reaction of l,r- is (P-aminoethyl)feiTocene (97) with diisocyanates (98) and diacid chlorides (100). These polymers were prepared via solution or interfacial polycondensation reactions to yield polymers with intrinsic viscosities ranging from 0.1 to LSdr/g. ... 

In recent years the concept of introducing H-bonding units into polyesters was used for the synthesis of poly(ester-amide)s and poly(ester-urethane)s, in order to improve the mechanical properties of already known and applied biodegradable polyesters like poly(butylene adipate) . Polycondensation and interfacial polycondensation reactions were applied to obtain materials from various diacids and diamines, amino alcohols or amino acids. In general these materials are biocompatible, biodegradable, and very promising for applications in the biomedical and pharmaceutical field, such as controlled drug delivery devices" . 

Controlling of Interfacial Polycondensation Reaction and Using Catalist... 

Interfacial polymerization is mainly used in polycondensation reactions with very reactive monomers. One of the reactants, usually an acid... 

We have put this model into mathematical form. Although we have yet no quantitative predictions, a very general model has been formulated and is described in more detail in Appendix A. We have learned and applied here some lessons from Kilkson s work (17) on interfacial polycondensation although our problem is considerably more difficult, since phase separation occurs during the polymerization at some critical value of a sequence distribution parameter, and not at the start of the reaction. Quantitative results will be presented in a forthcoming pub1ication. 

The vast majority of chemical reactions are sufficiently slow not to observe a dramatic influence of mixing on yields and selectivities. Exceptions are polymerizations, interfacial polycondensations, precipitations, and some fast reactions - usually performed in semibatch mode - such as autocatalytic reactions, neutralizations, nitrations, diazo couplings, brominations, iodinations, and alkaline hydrolysis, which are often encountered in the manufacture of fine chemicals. 

We now report a convenient method for the interfacial polycondensation of 1,1 -bis(3-aminoethyl)ferrocene (1) with a variety of diacid chlorides and diisocyanates, leading to ferrocene-containing polyamides and polyureas. In some instances, we have been able to observe film formation at the interface. Moreover, the polymerization reactions can be conveniently conducted at ambient temperatures in contrast to earlier high-temperature organometallic condensation... 

Aromatic polycarbonates are currently manufactured either by the interfacial polycondensation of the sodium salt of diphenols such as bisphenol A with phosgene (Reaction 1, Scheme 22) or by transesterification of diphenyl carbonate (DPC) with diphenols in the presence of homogeneous catalysts (Reaction 2, Scheme 22). DPC is made by the oxidative carbonylation of dimethyl carbonate. If DPC can be made from cyclic carbonates by transesterification with solid catalysts, then an environmentally friendlier route to polycarbonates using C02 (instead of COCl2/CO) can be established. Transesterifications are catalyzed by a variety of materials K2C03, KOH, Mg-containing smectites, and oxides supported on silica (250). Recently, Ma et al. (251) reported the transesterification of dimethyl oxalate with phenol catalyzed by Sn-TS-1 samples calcined at various temperatures. The activity was related to the weak Lewis acidity of Sn-TS-1 (251). 

The Schotten-Baumann reaction between dicarboxylic acid dichlorides and diamines can be performed not only in organic solvents, but also, by means of a special experimental technique known as interfacial polycondensation (see Examples 4-5 and 4-11). Both variants have the advantage of short reaction times at low temperature with simple equipment. 

The reaction between a dihydroxy compound (bisphenol) and phosgene, which is performed on an industrial scale, proceeds even at room temperature.The reaction is generally carried out in a biphasic medium consisting of methylene chloride (with dissolved phosgene) and aqueous sodium hydroxide (with dissolved bisphenol sodium salt) and a phase transfer catalyst (e.g.triethylamine).The procedure is termed interfacial polycondensation (see Sect.4.1.2.3 and Examples 4-5,4-12,and 4-13). 

Fully aromatic polyamides are synthesized by interfacial polycondensation of diamines and dicarboxylic acid dichlorides or by solution condensation at low temperature. For the synthesis of poly(p-benzamide)s the low-temperature polycondensation of 4-aminobenzoyl chloride hydrochloride is applicable in a mixture of N-methylpyrrolidone and calcium chloride as solvent. The rate of the reaction and molecular weight are influenced by many factors, like the purity of monomers and solvents, the mode of monomer addition, temperature, stirring velocity, and chain terminators. Also, the type and amount of the neutralization agents which react with the hydrochloric acid from the condensation reaction, play an important role. Suitable are, e.g., calcium hydroxide or calcium oxide. 

As in the preparation of polyesters, also in the preparation of polyamides, the reaction temperature can be considerably reduced by using derivatives of dicarbo-xylic acids instead of the free acids. Especially advantageous in this connection are the dicarboxylic acid chlorides which react with diamines at room temperature by the Schotten-Baumann reaction this polycondensation can be carried out in solution as well as by a special procedure known as interfacial polycondensation (see Examples 4-11 and 4-12). 

Syntheses. Interfacial Polycondensation. Morgan has discussed low temperature polycondensations involving room temperature reactions of fast-reacting intermediates under interfacial conditions (II). In his many papers (9) concerning this method of polymer preparation, in the published work of Conix (I, 2, 3), and in our own patent (6), the application of interfacial polycondensation to polyphthalate and to polysulfonate preparation is well described. Hence, we dwell only briefly on the interfacial method to make available our observations particularly with regard to scaleup problems. 

A multistep reaction pathway leads to polymers 43 and 44 with phosphatidylcholine moieties in the main chain and long alkyl groups in the side chain [122]. These polymers exhibit thermotropic liquid-crystalline behavior. Polyamides 45 were obtained by interfacial polycondensation they are insoluble in any normal solvent [123]. Poly-MPC capped with cholesteryl moieties at one or both polymer ends was prepared by the radical polymerization of MFC initiated with 4,4 -azobis[(3-cholesteryl)-4-cyanopentanoate] in the presence of a chain transfer agent [124]. The self-organization of these polymers was analyzed with fluorescence and NMR measurements. 

Interfacial polycondensations can also be carried out in vapor-liquid systems. Reaction takes place at the interface between an aqueous solution of a bifunctional active hydrogen compound and the vapor of diacid chloride. Interfacial condensation is commercially important in the synthesis of polycarbonates (1-52). Polymerizations based on diacids are always less expensive than those that use diacid chlorides. In the polycarbonate case, however, the parent reactant, carbonic acid, is not suitable and the derived acid chloride, phosgene (COCI2), must be used. 

Interfacial polycondensation. A variation of solution polymerization known as interfacial polymerization takes place when the two monomers are present in two immiscible solvents. Reaction then takes place at the... 

Emulsion systems, while widely used in the polymerization of unsaturated monomers, are used rarely for polycondensation. The emulsion system is one in which two (or more) liquid phases are present, md in which polymerization occurs entirely in the bulk of one of the phases and is almost exclusively kinetically controlled. It thus represents a transition from solution polymerization to interfacial polymerizations. In the case of polycondensation reactions, emulsion polymerization has not been studied in detail. Results thus far indicate that molecular weight and molecular weight distribution are subject to the same statistical considerations as apply to solution and melt polymerizations. 

Interfacial polycondensation has been studied in considerable detail in recent years, since this technique is quite useful for preparing high-melting polymers for fibre and other applications. This polymerization takes place in a two-phase system, with the propagation reaction occurring at or very near the interface. The mechanism is essentially diffusion controlled. 

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