By Interfacial Polycondensation

Preparation of Polyamide-6,10 from Hexamethylenediamine and Sebacoyl Dichloride in Soiution and by Interfacial Polycondensation 

Safety precautions Before this experiment is carried out, Sect. 2.2.5 must be read as well as the material safety data sheets (MSDS) for all chemicals and products used. 

The alcohol-free chloroform required for this experiment is first prepared by running 70 ml of chloroform through a column filled with basic aluminum oxide. 

Sebacoyl dichloride is obtained as follows 20 g of sebacoic acid and 50 g of thionyl chloride are refluxed on a water bath for 2 h.The excess thionyl chloride is then distilled off and the sebacoyl dichloride fractionated in vacuum (bp 142 °C/2 torr). 

A solution of 3 ml (14 mmol) of freshly distilled sebacoyl dichloride (for preparation see above) in 100 ml of carbon tetrachloride is placed in a 250 ml beaker. A solution of 4.4 g (38 mmol) of hexamethylenediamine in 50 ml of water is carefully run on to the top of this solution, using a pipette. (The aqueous solution can be made more readily visible by coloring it with a few drops of phenolphthalein solution.) A polyamide film is immediately formed at the interface and can be pulled out from the center with tweezers or clamps and laid over some glass rods it can now be pulled out continuously in the form of a hollow thread and wound up on to a spool driven by a slow-running motor. The polycondensation comes rapidly to a standstill if the motor is stopped, but immediately recommences, even after some hours, when the motor is restarted. 

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A polyether-amide with a heat distortion temperature of 198°C has been prepared by Hitachi by interfacial polycondensation of 2,2-bis-[4-(4-aminophen-oxy)phenyl]propane (VIII) with a mixture of isophthaloyl- and terephthaloyl-chloride (IX and X) (Figure 18.29). 

Tough, transparent, heat and flame resistant, multiblock (bisphenol fluorenone carbonate) (BPF)-dimethylsiloxane copolymers have been synthesized by interfacial polycondensation of phosgene with various mixtures of BPF end-capped siloxane oligomers and free BPF or its monosodium salt 232). Siloxane content of the copolymers were varied between 7 and 27%. Presence of two Tg s, one below —100 °C and the other as high as 275 °C, showed the formation of two-phase morphologies. 

Preparation of a Thermotropic, Main-Chain Liquid Crystalline (LC) Polyester by Interfacial Polycondensation... 

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. 

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],... 

Crespy D, Stark M, Hoffmann-Richter C, Ziener U, Landfester K (2007) Polymeric nanoreactors for hydrophilic reagents synthesized by interfacial polycondensation on miniemulsion droplets. Macromolecules 40(9) 3122-3135... 

G. B. Beestman and J. M. Deming, Encapsulation by Interfacial Polycondensation and Aqueous Herbicidal Composition Containing Microcapsules Produced Thereby. United States Patent 4,280,833, 1981. 

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. 

Polyesters obtained by interfacial polycondensation of aliphatic and aromatic diacids with dialkyl lead dichloride or dialkyl stannum dichloride possess biocide properties [105]. Ferrocene moieties may be also incorporated. 

Polymeric N202-chelates may be obtained by polyreaction of a bifunctional low molecular N202-chelate instead of constructing the chelate system during polycondensation. But only few results show a new way for the future. Bifunctional low molecular dielates (136) solved in NaOH were condensed with bifunctional aromatic acid chlorides solved in CH2Q2 by interfacial polycondensation >. Insoluble polychelates (137) were obtained (Eq. 69). 

Ferrocene has been reported to be very effective as a soot reducing agent in combustion [42 — 44]. Thus, when ferrocene compounds are incorporated in a fire retardant polymer, such as a phenolphthalein-based polymer and poly(phosphate ester)s, they have shown added advantages in that they promote extinction and reduce smoke formation by accelerated char reduction [45, 46]. The synthesis of such ferrocene-containing poly(phosphate ester)s was achieved by interfacial polycondensation using a phase transfer catalyst [47]. Accordingly, l,l -bis(p-hydroxy-phenylamido)ferrocene and l,l -bis(p-hydroxyphenylcarbonyl)ferrocene underwent condensation with various aryl phosphoroic acid dichlorides to yield two series of ferrocene-containing polymers, i.e., poly (amide-phosphate ester)s 38a and poly(ester-phosphate ester)s 38b respectively, as shown in Scheme 10-17. 

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... 

Dobkowski, Z. Weilgosz, Z. Krajewski, B. Molecular weight control of polycarbonates obtained by interfacial polycondensation. Angew. Makromol. Chem. 1974, 39 (1), 7-20. 

The stirrer power per unit volume was maintained constant with P/V = 0.5 or 1.0 kW/m After 30 minutes stirring the samples were fixed by interfacial polycondensation with a diamine. 

Journal of Microencapsulation 18, No.6, Nov./Dec. 2001, p.801-9 MORPHOLOGY AND STRUCTURE OF MICROCAPSULES PREPARED BY INTERFACIAL POLYCONDENSATION OF METHYLENE BIS(PHENYL ISOCYANATE) WITH HEXAMETHYLENE DIAMINE Jabbari E... 

The preparation of polyamides having metallocenes incorporated into the backbone can be achieved by the use of bifunctional ferrocene derivatives, such as diacid chlorides or diamines. In the following, a few examples of such reactions are presented. In the early 1960s Knobloch and Rauscher reported the preparation of polyamides and polyesters by the reaction of 1,1 ferrocenyldicarbonyl chloride 14 with several diamines and diols by interfacial polycondensation.80 The synthesis of elastomeric polyamides 54a, Mn = 10,000-18,000) in high yields was reported by Rausch and co-workers from 1,1 -bis((3-aminoethyl)ferrocene 53 and diacid chlorides (Scheme 12.11). The reaction with bis-isocyanates allows the formation of ferrocene-containing polyureas 54b. 

The melting and glass transitions in commercial Nylons and both homo-and copolyamides prepared by interfacial polycondensation have been studied by DTA by Ke and Sisko (171). The ETTA curves for a number of the polyadipamides and polysebacamides are given in Figure 7.54. 

A. D. Crespy, M. Stark, C. Hoffmann-Richter, U. Ziener, K. Landfester, Polymeric nanoreactors for hydrophilic reagents synthesized by interfacial polycondensation on miniemulsion droplets. Macromolecules, 2007, 40, 3122 b) O. Gazit, R. Khalfln, Y. Cohen, R. Tannenbaum, Self-assembled diblock copolymer nanoreactors as catalysts for metal nanoparticle synthesis, J. Phys. Chem. C, 2009, 113, 576. 

Polycarbonates are characterized by the carbonate (-0-COO-) interunit linkage. They may be prepared by interfacial polycondensation of bisphenol A and phosgene in methylene chloride-water mixture. The resulting hydrogen chloride is removed with sodium hydroxide or, in the case of solution polymerization, pyridine is used as the hydrogen chloride scavenger. Polycarbonate may also be made by ester interchange between bisphenol A and diphenyl carbonate. 

Aromatic polyamide fibers, better known as aramid fibers, have been defined as a long chain synthetic polyamide in which at least 85% of the amide linkages are attached directly to two aromatic rings [42] The first significant material of this type was introduced in 1961 by Du Pont as Nomex. It is poly(m-phenyleneisophthalamide), prepared from m-phenylenediamine and isophthaloyl chloride by interfacial polycondensation. 

Microencapsulation by interfacial polycondensation is a usefiil method to microencapsulate a liquid core material. Especially, polyurea and polyurethane microcapsules have been extensively investigated in various industries [209]. For example, aliphatic hexamethylene diisocyanate (HMDI) and aliphatic ethylene diamine (EDA) have been used to prepare polyurea microcapsules containing insecticide called diazinon [210]. A urea linkage is formed immediately by the reaction between an amine and an isocyanate group (see Figure 4.31), and a polyurea is synthesized by the reaction between an amine with two or more amine groups and an isocyanate with two or more isocyanate groups. 

Preparation of thin films by interfacial polycondensation A typical procedure for preparation of a free-floating interfacial film was as follows. A 1 mM solution of 29 (R = COCl) in chloroform was added to a Petri dish, and an equal volume of 1 mM 29 (R = -OH) in pH 11 carbonate buffer was carefixlly layered on top. After 1-3 h reaction time, the aqueous layer was removed by pipet until the interfacial film breaks and folds over the retreating aqueous buffer solutions. The wet film is then deposited onto an appropriate substrate for subsequent analyses, wetted with 2-propanol, and allowed to air-dry overnight. The same technique provided polyporphyrin films made from 29 (R = COCl) and aliphatic polyamines such as ethylenediamine, diethylene-triamine and poly(ethyleneimine), although significantly shorter reaction times (several minutes) are sufficient and substantially thicker films result. 

Janssen, E. J. J. M. Te Nijenhuis, K. Encapsulation by interfacial polycondensation. II. The membrane wall structure and the rate of the wall growth. Journal of Membrane Science (1992), 65(1-2), 69-75. 

Pense, A. M. Vauthier, C. Benoit, J. P. Preparation of microcapsules containing water-soluble amphi-philes by interfacial polycondensation. EP 407257, 1991. 

Valea, A. Miguez, J. C. Juanes, F. J. Gonzalez, M. L. Microencapsulation of paraffins as phase change materials by interfacial polycondensation of a polyamide. Comunicaciones presentadas a las Jomadas del Comite Espanol de la Detergencia (2007), 37, 335-346. 

Frere, Y Danicher, L Gramain, P. Preparation of polyurethane microcapsules by interfacial polycondensation. European Polymer (1998), 34(2), 193-199. 

Liang, C. Lingling, X. Honbo, S. Zhibin, Z. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system. Energ Comer Manag 50 (2009) 723-729. 

The molecular weight of polymers made by interfacial polycondensation is far less sensitive to nonequivalence of reactants than that of polymers prepared by melt or solution methods for reasons already discussed—high reaction rate, diffusion control of monomers, and the nonequilibrium nature of the polymerization. The molecular weight of polymers precipitating as a coherent film from an unstirred interface is completely insensitive to the contents of the system as a whole, whereas the molecular weight of polymers from a stirred interface is generally more sensitive to reactant nonequivalence. 

The thermal reaction of cobalt polymers 4.28 with isocyanates at 120 °C leads to 2-pyridone-containing polymers such as 4.30 [70]. Well-characterized, yellow polyesters 4.31 containing skeletal (cyclobutadiene)cobalt moieties in the main chain have been prepared by interfacial polycondensation approaches [73]. The use of solubilizing alkoxy substituents R afforded materials with Mn = 5,400-16,300 (PDI = 1.3-1.8). Analogous materials to 4.31 with a 1,3-disposition of the main-chain substituents on the cyclobutadiene ligands have also been studied [73, 74]. Thermotropic liquid crystallinity was detected by polarizing microscopy, with, in some cases, mesophases stable over the temperature range from about 110 to >250°C. 

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