Polyarylates. III. Kinetic studies of interfacial polycondensation

The kinetics of interfacial polycondensation of bisphenol A with isophthaloyl chloride and terephthaloyl chloride in dichloromethane with triethylbenzylammonium chloride (TEBAC) as the catalyst was investigated via measurements of bisphenolate concentration by UV. The reaction was found to be second order with respect to bisphenolate. The dependence of the rate constant on stirring speed, amount of TEBAC, and reaction temperature was studied. The rate constant was increased with an increase of stirring speed, quantity of TEBAC added, as well as the reaction temperature. The activation energy was found to be 7.7 kcal/mol at a stirring speed of 700 rpm in the presence of 0.160 of TEBAC. The role of TEBAC was found to be interesting. It did not alter the equilibrium (the partition coefficient remained the same in the presence of TEBAC), but it did enhance the transfer rate of bisphenolate.     

Polyarylates. IV. Synthesis of block copolymers via two-step interfacial polycondensation

A new method for preparing block copolyarylates via two-step interfacial polycondensation is proposed. First, oligomers with acid chloride end groups were obtained from interfacial polycondensation with a mole ratio of bisphenol A to diacid chloride(s) less than I. In the second step, two reaction systems containing various oligomers were mixed thoroughly and more bisphenolate was charged into this mixture. The synthesis of the block copolyarylates was justified from the viewpoint of statistics, and of differences in molecular weight between oligomers and block copolymers. These block copolyarylates could be differentiated from polyarylates through crystal-line behavior and solubility in m-cresol analyses.     

Polyarylates (I): Investigation of the interfacial polycondensation reaction by UV

The interfacial polycondensation of bisphenol A with isophthaloyl chloride and terephthaloyl chloride in dichloromethane with triethylbenzylammonium chloride as the catalyst was described. A well-defined two-phase system had been observed, so the concentration of bisphenolate in the aqueous phase could be determined by UV spectrometer. The conversion was found to increase rapidly with reaction time, but the rate of increase in molecular weight was slow. At the initial stage with conversion up to 95%, the reaction proceeded similarly to that of solution polycon-densation because the synthesized polyarylate could be dissolved in dichloromethane, and a polymer with a low molecular weight resulted. At the final stage of the reaction, the molecular weight was increased to a very high value due to the local concentration effect. The mole ratio of bisphenol A to diacid chlorides was found to affect the molecular weight very much. In the case of a mole ratio less than 1, the reaction remained in the initial stage mostly, and the molecular weight was low. However, for a mole ratio greater than 1, polyarylate with a very high molecular weight could be obtained because the local concentration effect was much more significant owing to the high concentration of bisphenolate that remained in the aqueous phase at the final stage.     

Linear polythioesters. VIII. Products of interfacial polycondensation of 1,4-di(mercaptomethyl)-tetramethylbenzene with isomeric phthaloyl chlorides

New polythioesters by interfacial polycondensation of 1,4-di(mercaptomethyl)-tetramethylbenzene with phthaloyl, isophthaloyl, and terephthaloyl chlorides were obtained. To determine the optimal conditions of interfacial polycondensation the influence of the following factors on yield and value of reduced viscosity were studied: type of organic phase, the quantitative ratio of aqueous to organic phase, concentration of hydrogen chloride acceptor, molar ratio of reagents, rate of acid chloride addition, contribution of benzyltriethylammonium chloride as a catalyst, and the temperature of the reaction. The yield of all reaction products and the reduced viscosity of polythioesters which were soluble in the mixture of phenol-tetrachloroethane were found. A thorough examination was carried out only for the polycondensation of dithiol with isophthaloyl chloride. The structure of all polythioesters obtained under the model conditions was determined by elementary analysis and infrared spectra. Initial decomposition temperature and maximum rate of decomposition temperature were defined from the curves of thermogravimetric analysis. Some mechanical and electrical properties of the polythioesters were determined. The molecular weight was not measured because of the low solubility of the obtained polythioesters.     

Preparation and properties of polyesters and copolyesters based on 4-methyl-2,4-bis (p-hydroxyphenyl)-1-pentene

4-Methyl-2,4-bis (p-hydroxyphenyl)-1-pentene (MBHPP) was prepared from thermal cracking of bisphenol A (BPA). Unsaturated polyesters were synthesized from the polycondensation of MBHPP with diacid chlorides. Three synthetic routes—solution, interfacial, and melt polycondensation—were employed. MBHPP-polyesters with higher molecular weights were obtained by the interfacial polycondensation reaction. During the preparation of MBHPP-polysters, the products usually contain some insoluble gel, which is probably caused by the crosslinking reaction of the vinyl groups of MBHPP in the aqueous NaOH. Thus, a modified interfacial polycondensation method was proposed, in which both of the bisphenol MBHPP and diacid chloride were dissolved in organic phase and then the solution was stirred with an aqueous NaOH solution to promote the polycondensation. This method reduced the time of MBHPP present in the alkali and produced polymers with higher inherent viscosity and lower gel fraction. The effects of some variables, such as the nature of porganic solvents and phase transfer agents and the concentration of reactants, on the modified interfacial polycondensation of MBHPP with the mixture of equal parts of isophthaloyl and terephthaloyl chloride [IPC/TPC (50/50)] were investigated in some detail. Copolyesters of mixed bisphenols of BPA/MBHPP with IPC/TPC (50/50) were also prepared and characterized.     

Interfacial sythesis of polyphosphonate and polyphosphate ester. VII. Temperature effects and reaction loci in polycondensations of hydroquinone with phenylphosphonic dichloride and 4-methythiophenyl phosphorodichloridate

Polyphosphate and polyphosphonate esters of molecular weights > 10,000 were synthesized by base-promoted, liquid-vapor and liquid-liquid interfacial polycondensations of hydroquinone (HQ) with 4-methylthiophenyl phosphorodichloridate (MTPP) and phenylphosphonic dichloride (PPD). The barium hydroxide-initiated liquid-vapor polycondensation of PPD and HQ in the temperature range of 15–95°C shows that [η] increases with reaction temperature and unfractionated yields exhibit a maximum at about 45°C. The analogous liquid-vapor polycondensation of MTPP and HQ between 25 and 85⁴C also shows a maximum yield at 45°C, whereas [η] decreases with increase in reaction temperature. The results are contrasted with temperature dependencies of base-catalyzed, liquid-liquid polycondensation of HQ with MTPP and PPD. A different insight is obtained by analyzing the temperature effects on fractionated products. The relative importance of degradative saponification reactions are ranked as attack on chain ester linkages > phosphorus chloride reactant > end groups of growing chains.     

The kinetics of polycondensation of α,α′‐dichloro‐p‐xylene with 4,4′‐isopropylidenediphenol using benzyltriethylammonium chloride as a phase‐transfer catalyst

The phase‐transfer catalyzed polycondensation of α,α′‐dichloro‐p‐xylene with 4,4′‐isopropylidenediphenol was carried out using benzylethylammonium chloride in a two‐phase system of an aqueous alkaline solution and benzene at 60 °C under nitrogen atmosphere. The rate of polycondensation was expressed as the combined terms of quaternary onium cation and 4,4′‐isopropylidenediphenolate anion rather than the feed concentration of catalyst and 4,4′‐isopropylidenediphenol. The measured concentrations of hydroxide and chloride anion in the aqueous solution and α,α′‐dichloro‐p‐xylene in the organic phase were used to obtain the reaction rate constant with the integral method, and to analyze the polycondensation mechanism with a cyclic phase‐transfer initiation step in the heterogeneous liquid–liquid system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3059–3066, 2000     

Linear polythioesters. VII. Products of interfacial polycondensation of 1,4-di(mercaptomethyl)-2,3,5,6-tetramethylbenzene with some aliphatic acid dichlorides

Several polythioesters by interfacial polycondensation of 1,4-di(mercaptomethyl)-2,3,5,6-tetramethylbenzene with oxalyl, succinyl, adipoyl, suberoyl, and sebacoyl chlorides were obtained. To determine the optimal conditions for interfacial polycondensation, the influence of the following factors on yield and value of reduced viscosity were studied: type of organic phase, concentration of hydrogen chloride acceptor, the quantitative ratio of aqueous to organic phase, molar ratio of reagents; temperature of reaction, rate of acid chloride addition, and contribution of catalyst. Thorough studies were carried out only for polycondensation of the dithiol with adipoyl and sebacoyl chlorides. The structure of all polythioesters obtained under the model conditions was determined by elementary analysis and infrared spectra. Initial decomposition temperature, mass loss in percentage at the same temperature, maximum rate of decomposition, and mass loss percentage at 100–400°C were defined by thermogravimetric analyses. Chemical resistance of the polythioesters was determined by treatment with some organic solvents, mineral acids (concentrated and 10%), and sodium hydroxide (10 and 50%). Some mechanical and electrical properties of the polythioesters obtained from dithiol and adipoyl and sebacoyl chlorides were determined. The molecular weight was not measured because of the low solubility of the polythioesters.     

Linear polythioesters. V. Products of interfacial polycondensation of 4,4′-di(mercaptomethyl)-benzophenone with some aliphatic acid dichlorides

New polythioesters by interfacial polycondensation of 4,4′-di(mercaptomethyl) benzophenone with oxalyl, succinyl, adipoyl, suberoyl, and sebacoyl chlorides were obtained. To determine the optimal conditions for interfacial polycondensation the influence of the following factors on yield and value of reduced viscosity were studied: type of organic phase, the quantitative ratio of aqueous and organic phase, concentration of hydrogen chloride acceptor, molar ratio of reagents, temperature of reaction, rate of acid chloride addition, and contribution of catalyst and emulsifier. A thorough examination was carried out only for polycondensation of dithiol with adipoly and sebacoyl chlorides. The structure of all polythioesters obtained under the model conditions was determined by elementary analysis and infrared spectra. Initial decomposition and initial intensive decomposition temperature were defined from the curves of thermogravimetric analysis. Some mechanical and electrical properties of the polythioesters obtained from 4,4′-di(mercaptomethyl)benzophenone and adipoyl and sebacoyl chlorides were determined. The molecular weight was not measured because of the low solubility of the obtained polythioesters.     

Linear polythioesters. IX. Products of interfacial polycondensation of 4,4′-dimercaptobenzophenone with some aliphatic acid dichlorides

By interfacial polycondensation of 4,4′-dimercaptobenzophenone with oxalyl, succinyl, adipolyl, suberoyl, and sebacoyl chlorides new polythioesters were obtained. To determine the optimal conditions of interfacial polycondensation the influence of the following factors on yield and value of reduced viscosity was studied: type of organic phase, the quantitative ratio of aqueous to organic phase, concentration of hydrogen chloride acceptor, molar ratio of reagents, temperature of reaction, rate of acid chloride addition, and contribution of catalyst. A thorough examination of the polycondensation of dithiol with adipolyl and sebacoyl chlorides was carried out. The structure of all polythioesters obtained under model conditions was determined by elemental analysis and infrared spectra. Initial decomposition and intensive decomposition temperature were defined by the curves of thermogravimetric analysis. Mechanical and electrical properties of the polythioesters obtained from 4,4′-dimercaptobenzophenone and adipoyl and sebacoyl chlorides were determined. The molecular weight was not measured because of the low solubility of the polythioesters.     

Linear polythioesters. III. Products of interfacial polycondensation of 1,4-, 1,5-di(mercaptomethyl)-naphthalene,and their mixture with adipoyl and sebacoyl chlorides

New polythioesters of naphthalene derivatives by polycondensation of 1,4-di(mercaptomethyl)-naphthalene, 1,5-di(mercaptomethyl)naphthalene, as well as their mixture with adipoyl and sebacoyl chlorides have been obtained. Low-temperature and high-temperature solution polycondensation as well as interfacial polycondensation have been used. Interfacial polycondensation proved to be the most useful. To define the optimal conditions of interfacial polycondensation, the following factors influencing the process have been studied: ratio of aqueous to organic phase, concentration of hydrochloride acceptor, temperature of reaction and rate of addition of acid chloride, contribution of emulsifier and catalyst. Yield for all reaction products and reduced viscosity have been found. The structure of polythioesters of high-value viscosity and good yield was determined from elementary analysis, infrared spectra, x-ray, and thermogravimetric analysis. Some mechanical and electrical properties of the polythioesters obtained from the mixture of 1,4- and 1,5-di(mercaptomethyl)naphthalene have been studied after pressing in increased temperature. The molecular weight was not determined because of very low solubility.     

Study of the interfacial polycondensation of isocyanate in the preparation of benzalkonium chloride loaded microcapsules

The preparation of benzalkonium chloride loaded microcapsules was performed by interfacial polycondensation of isocyanates. The present study was made in order to clarify parameters affecting microcapsule wall formation during the course of polymerization. The results presented here show that many interrelated parameters are involved during the microcapsule formation. Each individual component introduced in the preparation was shown to have an effect either on the morphology of the microcapsules or on the mechanical resistance. Benzalkonium chloride seemed to interact mainly in the interfacial polymer precipitation step through a salt effect, or influence the polycondensation reaction rate acting as a catalyst. A contribution of the hydroxylic functions of the surfactant in the polycondensation reaction of the isocyanate was also highlighted. Finally, the organic phase composition was found to be able to modulate the reactivity of hydroxylic functions of the surfactant, leading to very slow reactions in pure xylene. These effects were related to the characteristics of the microcapsules obtained according to different compositions of the formulation system.     

Synthesis of high molecular weight poly(ether ketone)s by polycondensation of activated bis(aryl chloride)s with bisphenolates

The ability to achieve high molecular weight poly(ether ketone)s from the polycondensation of bis(aryl chloride)s with bis(phenolate)s has been consistently demonstrated. The polymerizations presented here help to delineate for specific bis(aryl chloride)/bisphenolate pairs the reaction conditions required to obtain high molecular weight polymers. Polycondensation of 1,3-bis(4-chlorobenzoyl)-5-tert-butylbenzene ( 6 ) and 2,2′-bis(4-chlorobenzoyl)-biphenyl ( 15 ) with various bisphenolates as well as of 2,2′-bis(4-hydroxyphenoxy)biphenyl ( 33 ) with 4,4′-dichlorobenzophenone ( 41 ) and 1,3-bis(4-chlorobenzoyl)benzene ( 43 ) were used as representative model systems to select reaction conditions that led to high molecular weight polymers. © 1995 John Wiley & Sons, Inc.     

Synthesis of reactive aromatic polyesters having pendant chlorohydrin moieties

A monomer containing a chlorohydrin moiety, propyl chlorohydrin diphenolate (PCHDP), was synthesized. Reactive polyesters having these pendant chlorohydrin moieties were prepared by the interfacial polycondensation of isophthaloyl chloride with PCHDP or with PCHDP and diphenolic acid using phase transfer catalyst. The molar ratio of reactants and the phase ratio of water to organic solvent strongly affect the molecular weight of resulting polymers and polymers with high molecular weight are obtained at the molar ratio of 1.0–1.15 and the phase ratio of 2.0–3.5. Swelling of the growing polymers is dependent on the molar ratio of the reactants and the phase ratio because of the hydrophilic and hydrophobic nature of the pendant chlorhydrin moiety. The resulting polymers are not soluble in any solvent except water in which hydrolysis occurs. Thus so, the structure of polymers was confirmed by ¹³C CP/MAS NMR. © 1996 John Wiley & Sons, Inc.     

Synthesis of Aromatic Polyesters Bearing Pendant Carboxyl Groups by Phase Transfer Catalysis

Aromatic polyester (PEA) and copolyesters having pendant carboxyl groups aredirectly synthesized from isophthaloyl chloride, diphenolic acid and diols byaqueous/organic two-phase interfacial polycondensation, using phase transfercatalysts. The yield and molecular weight of the polyester were remarkablyaffected by the structure of quaternary ammonium salts and crown ether catalysts.The phase transfer reaction steps are suggested to explain this phenomena. Theproperties of copolyesters were dependent on the original structure of diols.     

s‐Triazine‐based hyperbranched polyethers: Synthesis,characterization, and properties

A series of s‐triazine‐based hyperbranched polyethers (HBPE) have been synthesized to obtain thermostability but flexible polymers by an interfacial polycondensation of different diols as A₂ and cyanuric chloride as B₃ monomers using A₂ + B₃ approach in the presence of a phase transfer catalyst. The polymerization reaction parameters are optimized, and the results indicate that the optimum conditions for the interfacial polycondensation are a 2:3 mole ratio of cyanuric chloride to diol using butanediol, benzyldimethylhexadecyl ammonium chloride as the catalyst, dichloromethane as the organic solvent, and a three‐step procedure with keeping the reaction mixture at different low temperatures for 2h/2h/5h. Other techniques such as high‐temperature solution, one‐step polycondensation, and transesterification were also carried out to synthesize the HBPE but proved to be not suitable due to large number of side reactions. The synthesized polymers were characterized by FTIR, ¹H NMR, and ¹³C NMR spectroscopy, hydroxyl number determination, solution viscosity measurements, and GPC analysis. The thermal behavior of the hyperbranched polymer was investigated by thermogravimetric analysis and differential scanning calorimetry. All the results were compared with those from an analogous linear polyether, obtained from 2‐methoxy‐4,6‐dichloro‐s‐triazine and butanediol by using the same polymerization technique. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3994–4004, 2010     

Effect of chelation on the polycondensation of monomers having an active ester group

Various amino acid esters and dicarboxylic acid esters having a β-thioether group have been synthesized and their polycondensation with diamine was found to occur at room temperature to form polyamide thioether. The effect of solvents or chelating agents on their polycondensation reaction was investigated. Metal acetylacetonates or inorganic salts had a great influence on the rate of the polycondensation reaction, and the catalytic activity of metal acetylacetonates M(AcAc)_n or inorganic salts decreased in the following order: Mg(AcAc)₂?Th(AcAc)₄>Cu(AcAc)₂>Li(AcAc)>None>Zr(AcAc)₄, MgCl₂·6H₂O>CuCl₂·.2H₂O>ZnCl₂>MgCl₂>None. It was also found that the amount of polyamide thioether was dependent on solvents or the presence of chelating agents because the polycondensation rate and the apparent equilibrium between ring and chain structures were both greatly influenced by solvents or chelating agents. These effects of solvents or chelating agent on the polycondensation may be attributable to formation of a complex with the thioether group which enhances the reactivity of ester.     

Interfacial activity of benzyloctadecyldimethyl ammonium chloride in a liquid/liquid extraction system

Interfacial tension and interfacial adsorption parameters for benzyloctadecyldimethyl ammonium chloride (BODMAC) in three organic diluents were determined and interpreted. The interfacial activity of BODMAC is affected by the type of the organic diluent and the composition of the aqueous phase. The general order of interfacial activity of BODMAC is n-heptane (5% isobutanol) > carbon tetrachloride > chloroform. The effectiveness of adsorption of BODMAC is not only dependent on the organic diluent, but also on the inorganic electrolytes in the aqueous phase.     

Synthesis of aromatic polyesters having pendant carboxyl groups in the side chains and conversion of the carboxyl groups to other reactive groups

Aromatic polyester, copolyester, and poly(ester-amide-thioester) having pendant carboxyl groups are directly synthesized by the organic phase/water phase interfacial polyconden-sation using low-molecular and polymeric phase transfer catalysts. Spectral analysis of the resulting polymers indicates that the nucleophilicity of salts of phenols to diacid chloride is far higher than that of salts of carboxylic acids and chemoselective esterification occurs in a 100% yield. Even if the polymeric catalyst having amino acid moiety as a nucleophilic group is used in the polycondensation, the polymers do not contain anhydride groups. The polyester can be almost quantitatively converted to polymers with different reactive groups by reacting the pendant carboxyl groups with alkyl halides in a DMA_c-H₂O mixture con-taining K₂CO₃. A bifunctional catalytic mechanism is proposed for the chemical modification of the polyesters. © 1995 John Wiley & Sons, Inc.     

Synthesis of reactive copolyesters derived from isophthaloyl chloride,bisphenol a,and aliphatic diols with additional reactive groups

Copolycondensation of isophthaloyl chloride, bisphenol A, and aliphatic diols with additional reactive groups were performed in the presence of triethylamine by a trimethyl phosphate/cyclohexane organic/organic interfacial method. The composition of idol and bisphenol A residues in the resulting copolyesters is very close to that in the feed from the initial stage of reaction. The resulting copolyesters with reactive groups can be used for the preparation of various functional polymers. The mechanism of an organic/organic interfacial polycondensation was also discussed. © 1995 John Wiley & Sons, Inc.