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Novel polyion complex membranes were prepared from DNA-Na and poly(4-vinylbenzyl)trimethylammonium chloride (PVBTMAC). The newly prepared DNA-PVBTMA polyion complex membranes showed a chiral separation ability toward racemic lysine (Lys) mixtures. The membranes transported D-Lys in preference to the corresponding L-isomer of Lys. The permselectivity toward the D-isomer reached 1.26. From transport experiments and adsorption studies, it was revealed that the permselectivity was mainly determined by diffusivity selectivity.

Styrene (St) was polymerized in mixed solvents of ethanol/n-hexane as good-poor solvents for matrix polymers such as poly(methylvinylether) (PMVE) in solution. Conformational change of the matrix polymer from extended to random coil structures provided different dimensional fields for in-situ polymerization of St, resulting in control of particle size and distribution of poly(St) (PSt). Neutron scattering of St solution suggested the formation of St monomer clusters in matrix polymer solution.

Poly(6-(acryloyloxymethyl)uracil) (PAU) having uracil moieties as side chains was synthesized by ordinary radical polymerization to investigate its molecular discrimination for soluble nucleic acid bases in terms of phase transition changes of the polymer aqueous solution. PAU itself in distilled water formed a precipitate due to the polymer complexes at lower temperatures and changed drastically to become water-soluble above a characteristic transition temperature, showing an upper critical solution temperature (UCST). The phase transition behavior was shifted to lower temperatures with increasing concentrations of adenosine (Ado), which is the complementary nucleic acid base to uracil moiety. Ado might interact specifically with uracil moieties of the polymers, preventing the formation of the polymer complex at lower temperatures. Such changes were not observed in PAU aqueous solution containing guanosine (Guo). Additions of Ado and Guo exerted different effects to phase transition changes of the polymer. Moreover, addition of poly(adenylic acid) (Poly(A)) lowered remarkably the transition behavior of PAU solution as compared with Ado addition. It was conceivable that PAU and Poly(A) formed stable polymer complexes, assuming soluble states in even cold water. PAU changed its phase-transition temperature in response to species of the additive materials, demonstrating the specific molecular discrimination in aqueous milieu.

The in-situ polymerization of acrylamide in solutions of poly(styrene) (PSt) was carried out by anionic polymerization to form Nylon 3 in PSt as micro-composites in which Nylon 3 was dispersed as fine particles. Copolymers of styrene (St) and 4-vinylpyridine (4-VPy) were used as matrix polymers in order to improve a compatibility between the in-situ formed Nylon 3 and matrix polymer through hydrogen-bonding. These micro-composites showed great improvement of mechanical properties owing to reinforcement by ultra-fine particles of Nylon 3. Especially, the micro-composite derived from poly(St-co-4-VPy) showed excellent improvements of mechanical properties owing to the hydrogen bonding interactions between Nylon 3 and 4-VPy.

Glucose-Sensitive Lower Critical Solution Temperature Changes of Copolymers Composed of N -Isopropylacrylamide and Phenylboronic Acid Moieties

Composites of elastomeric polymers and poly(γ-methyl L-glutamate) (PMLG) were prepared by the so-called “in-situ polycondensation method” and a solution blend method. Three types of rubbers were used as matrix polymers : styrene-butadiene copolymer and two derivatives. Mechanical properties of these composite polymers were studied by tensile tests and their morphologies were observed by scanning electron microscopy. The tensile strength and modulus of the composite films obtained by the in-situ polycondensation method increased with increasing PMLG content. Although their tensile modulus values increased drastically, their ultimate elongation values were almost the same. The morphologies of the composites and the reinforcing effect of PMLG were dependent on the preparation method, on the contents of PMLG, and on an interaction between matrix polymer and PMLG.

Acetalized poly(vinyl alcohol)s (PVA) having pendant nonlinear optically (NLO) active groups were synthesized in order to investigate second harmonic generation (SHG) by using two types of poling methods of NLO active moieties; namely, one was Langmuir-Blodgett (LB) orientation and the other was electric field (EF) poling. It was found that the new polymers having pendant NLO active groups showed sharp surface pressure-area (π-A) curves to form thin films on the surface of water but no active SHG was observed. On the other hand, the polymer films with a support of stearamide showed a SHG activity. When the new polymers were EF poled using colona poling method, SHG was also observed and the SHG activity was estimated as 40.8 pm V−1. The new NLO polymers poled by the EF method showed small SHG relaxation and were useful as a new type SHG material.

Interpenetrating polymer networks (IPNs) composed of poly(acrylamide(AAm)-co-butyl methacrylate (BMA)) and poly(acrylic acid) (PAAc) demonstrate positive swelling changes with an abrupt transition as temperature increases. Temperature-modulated controlled drug release using swelling-shrinking responses of the hydrogels as on-off switches for drug release is reported. The IPNs demonstrate “on” release at higher temperatures. When changing from higher to lower temperatures, an immediate pulsatile drug release is observed followed by a nearly complete “off” state of drug release. The drastic increase of drug release rate is due to mechanical squeezing by a shrinking gel surface layer of the IPNs in response to decreasing temperature. The following decrease of drug release is due to a subsequent formation of a dense layer of polymer at the IPN surface.

Direct polycondensation of p-aminobenzoic acid (ABA) or p-hydroxybenzoic acid (HBA) was carried out in solutions of polyarylate (copolyester from tere-/iso-phthalic acids (50/50) and bisphenol A) at 25°C in the presence of triphenylphosphine and hexachloroethane as an initiator for the direct polycondensation of these monomers. Solution casting after the direct polycondensation provided opaque films in which aromatic polyamide or polyester was finely dispersed within the matrix of polyarylate. Mechanical properties of these films indicated increase in modulus and tensile strength at elevated temperatures. In-situ direct polycondensation leads to the formation of new molecular composite materials.

Epoxy and formal derivatives of tartarate were found to be easily subjected to polycondensation reactions with hexamethylenediamine (HMD) in solutions under mild conditions and linear polyamides having epoxy or formal groups were obtained in a quantitative yield. The polycondensation reaction of epoxy succinate with HMD was influenced by solvents and a competitive reaction between a nucleophilic attack of amine to ester and epoxy groups was also influenced by solvents.Thus, a cross-linked polyamide was obtained from epoxy succinate and HMD. On the other hand, a linear polyamide was obtained from formal tartarate and HMD. The polyamide from formal tartarate and HMD suffered a cross-linked reaction among the formal groups on heating.

A new polymer, poly{1-(2-methylpropenoyloxy)phthalimide-co-acrylonitrile} (Poly(1-co-2)) was synthesized based on molecular designs for the separation of water and ethanol. The sequence distribution of the copolymers were investigated by 13C NMR spectroscopy. A terminal model was used to interpret the propagation process in the copolymerization. The reactivity ratios in the solution polymerization at 45°C were evaluated as r1=1.90 and r2=0.39. Radical reactivity indices and frontier electron densities were calculated. The membrane prepared from this copolymer carried out a selective separation of water from aqueous ethanol solution by pervaporation method. The separation factor toward water was as high as 1200.

Polymer Membrane as a Reaction Field II. Effect of Membrane Environment on Permselectivity for Water–Ethanol Binary Mixtures

The reaction of half esters derived from polyhydric alcohols including ethylene glycol or glycerol has been investigated. The reactivity of half esters toward the reaction with primary amine has been compared with the reactivity of ordinary esters. The reaction was enhanced by introducing hydroxyl groups into the alcohol moiety of esters, and it took place in solutions under mild conditions. The reactivity enhancement was related with the number of hydroxyl groups in the half esters; the half ester derived from glycerol reacted easily with amine with a much faster rate than ordinary esters. The reactivity enhancement owing to the hydroxyl group is explained by an interaction of the hydroxyl group with amine in solutions. A tentative experiment was carried out to prepare polyamide under mild conditions by using bis(2-hydroxyethyl) terephthalate.

Direct polycondensation reactions of various nylon salts prepared from diamines and dicarboxylic acids were carried out under mild conditions with triphenylphosphine and halides. Reaction conditions including the monomer concentration, amount of reagents, kind of halides, solvents and organophosphorus compounds, and temperature were investigated. A combination of triphenylphosphine and tetrabromomethane was found to be satisfactory for the aliphatic polyamide synthesis. Nylon 6, 10 having the highest molecular weight was obtained with the molar ratio of triphenylphosphine/tetrabromomethane/carboxyl groups of the monomer = 1.5/1.5/1.0 in pyridine at 40°C.

Pervaporation of Water–Ethanol through Synthetic Polymer Membranes Having Cationic Charge Sites

Temperature Dependence of Ionic Conductivity of Crosslinked Poly(propylene oxide) Films Dissolving Lithium Salts and Their Interfacial Charge Transfer Resistance in Contact with Lithium Electrodes

Diesters having heterocyclic nuclei, such as furan, thiophene, pyridine, and pyrazine, were found to undergo a polycondensation reaction with hexamethylenediamine in solutions under mild conditions. The reactivity enhancement of the diesters due to the introduction of heterocyclic nuclei could be arranged in the following order: pyrazine> pyridine> furan> thiophene. The enhancement effect of these heterocyclic nuclei was not directly related to the basicities of the diesters and it might be ascribed to the same reason as the enhancement described in previous papers.

Triphenylphosphine which is known as an effective initiator for direct polycondensation, was immobilized into polymers by polymerizing and copolymerizing with diphenylstyrylphosphine. Copolymerization behavior of diphenylstyrylphosphine with 4-vinylpyridine was analyzed. Polymeric triphenylphosphine could initiate the direct polycondensation to form either polyamide or polyester and a recycling system for the regeneration of triphenylphosphine moiety was proposed.

Synthesis of Aromatic Polyesters by Interfacial Polycondensation Using Immiscible Binary Solvents

Polycondensation of 1,4-bis(methoxycarbonylethyl)piperazine (MCEP) with hexamethylenediamine (HMD) was carried out in the presence of an electron-accepting matrix such as a nitrated polystyrene. A charge transfer complex was found to be formed between HMD and the matrix polymer and the rate of the polycondensation was enhanced by the adsorption of HMD in the matrix polymer of nitrated polystyrene.

The reaction mechanism of direct polycondensation with triphenylphosphine and hexachloroethane was investigated by gas chromatography, infrared and NMR spectroscopic analyses. It was found that pyridine participated in the reaction process of the direct polycondensation of dicarboxylic acid and diamine in the presence of triphenylphosphine and hexachloroethane in addition to serving as solvent and acid acceptor. The polyamide formation passed through an active acyl intermediate of carboxylic acid formed from triphenylphosphine and hexachloroethane in the presence of pyridine, followed by an aminolysis reaction with amine to form an amide linkage.

Diesters having hetero atoms such as oxygen or sulfur atoms at position α to the carbonyl group of the ester underwent a polycondensation reaction with diamines to form a polyamide under mild conditions in solution. The reactivity enhancement due to the introduction of α-hetero atoms in the esters could be arranged in the same order as that of the effect of β-hetero atoms: —O—>—S—>=N—. The enhancement effect of α-hetero atoms was superior to that of β-hetero atoms. On the other hand, the introduction of hetero atoms at position β to amino group retarded the polycondensation reaction with ordinary esters. The effect of hetero atoms on the reactivity of esters was discussed.

Polycondensation reactions of diesters and diamines having hetero atom groups such as ether or hydroxyl groups were carried out in polar solvents such as water and methanol. It was found that hetero atom groups such as ether or hydroxyl groups could greatly enhance the reactivity of diesters when introduced at α or β positions on ester carbonyl group, but that they did not change the reactivity of diamines. Polycondensation reactions took place in a methanol solution under mild conditions to form polyamides, while the hydrolysis reaction of the diesters occurred simultaneously with the polycondensation reaction, yielding nylon salts in aqueous solution. The apparent orders of the polycondensation reaction of these diesters with diamines were determined so as to analyze the polycondensation reaction.

Active and Selective Transports of Anions through Poly( N -propenoyl-9-acridinylamine- co -acrylonitrile) Membrane

Diesters having hydroxyl groups can react with diamines under mild conditions to form polyamides having pendant hydroxyl groups. The reactivity enhancement owing to the hydroxyl group was investigated in terms of the aminolysis reaction of aliphatic or heterocyclic hydroxyl diesters with butylamine. Apparent rate constants could be expressed in the following equation: kobs=k1[BuNH2]+k2[BuNH2]2 The enhancement effect of the hydroxyl group on the aminolysis reaction was interpreted either as the polarity change of the ester carbonyl group, in the case of heterocyclic diesters, or as the intermolecular hydrogen bonding with amine, in the case of aliphatic diesters.

Segmented polyether poly(urethane-urea-amide) (PEUUA)s containing poly(propylene oxide) (PPO) segments of various molecular weights were synthesized and their morphology and properties were characterized in comparison with the conventional segmented polyether poly(urethane-urea) (PEUU). PEUUAs consisted of two incompatible segments, soft segments with the repeating units of PPO and urethane group, and hard segments composed of urea and amide groups. Characterization of PEUUA was carried out by small-angle X-ray scattering, dynamic mechanical, tensile, and hysteresis measurements. A comparison of PEUUA and PEUU indicated that PEUUA had higher mechanical strength and hysteresis values. These favorable features were considered due to the hard domains composed of strongly hydrogen bonded segments dispersed in the matrix of the soft segments, resulting in hard domain interconnectivity.

Pervaporation of aqueous ethanol solution was carried out through three synthetic polymer membranes each containing an imide group, poly(N-phenylmaleimide-co-styrene)s and a polymer having an N-substituted phthalimide group. These membranes selectively permeated water. The water was assumed to be permeated by a carrier mechanism utilizing a carbonyl moiety of the imide group as a carrier, while ethanol was permeated through membranes without specific interaction between ethanol and membranes.

The relationship between microphase-separated structures and antithrombogenicities of poly(propylene oxide) (PPO)–segmented polyamides of various polyamide segment lengths was studied. Transmission electron microscopic observation revealed fibrillar lamella structures to be present on the copolymer surfaces. Dynamic mechanical and thermal scanning measurements showed the existence of two mechanical relaxations attributable to micro-Brownian motions of the PPO and polyamide segments, indicating that the PPO and polyamide segments formed distinctly separated microdomain structures. Moreover, wide-angle X-ray diffraction and small-angle X-ray scattering measurements indicated these copolymers to be different in their microstructures with respect to size and distribution of crystalline and amorphous domains even though the crystalline structure was essentially the same as that of nylon 610. The degree of platelet adhesion and aggregation was significantly minimized on the surface of the copolymer, in which the average diameter of the crystalline and amorphous domains were 6.42 nm and 5.18 nm, respectively. This suggests that the size of segmented polyamide microdomains may be a determining factor in antithrombogenicity.

Preparation des polymeres par polycondensation de la dimethyl-2,5 piperazine avec le dichlorure d'acide obtenu par reaction du chlorure de terephtaloyle avec des α,ω-alcanediols de longueur variable. Diminution de la Tg et des temperatures des 2 autres transitions observees en DSC lorsque la longueur de la chaine alkylene augmente

The polycondensation reaction of various dicarboxylic acids and diols such as terephthalic acid and ethylene glycol occurred at room temperature in pyridine in the presence of picryl chloride to give polyesters in high yield. Reaction conditions, basic solvents, temperatures, concentrations of monomer, and amount of picryl chloride were investigated. A combination of picryl chloride and pyridine was found to be satisfactory for the polyester synthesis. The polycondensation reaction possibly proceeds through the formation of an active ester from picrylic acid and carboxylic acid, followed by esterification with hydroxyl group. Yields of polyester from 2,5-pyridinedicarboxylic acid and 1,10-decanediol by this direct polycondensation reached up to 89%, and the solution viscosity of the polyester was approximately 1.0 under optimum reaction conditions. The polyester obtained from terephthalic acid and 1,5-pentanediol had a higher solution viscosity than those from various combinations of dicarboxylic acids and diols. Aliphatic dicarboxylic acid such as adipic acid yielded polyester having a lower solution viscosity than aromatic dicarboxylic acid.

The reaction mechanism of the polyamide synthesis by phosphorylation with triaryl phosphite and imidazole was investigated in terms of the amidation reaction of model compounds and the polycondensation of various nylon salts. Triphenyl phosphite formed a complex with imidazole which reacted easily either with amine or carboxylic acid to form acyloxy phosphite or phosphoramide complexes. The electron-donating substituent of phenol of aryl phosphites retarded the amidation and polycondensation reactions, and, among various tertiary amines, only imidazole had a cocatalytic effect. The low molecular weight of the resulting polyamide was ascribed to the many competitive reactions of the phosphite—imidazole complex between amine and carboxylic acid, which resulted in the molar balance loss of amine or carboxylic acid. The reaction mechanism for the polycondensation of nylon salt by phosphorylation was again discussed in this paper.

Ionic Conductivity and Mobility of Poly(propylene oxide) Networks Dissolving Alkali Metal Thiocyanates

The structure-conductivity relationships were investigated on the network polymers from poly(ethylene oxide)(PEO) containing lithium perchlorate (LiClO4), in contrast to the polymer complex formed by linear PEO and LiClO4. The crosslinked structure caused a considerable decrease in the degree of the crystallinity of the resulting PEO–LiClO4 complexes, which contributed to high ionic conductivity. Li+ ions were demonstrated as mobile species in these polymer complexes, while ClO4− ions contributed somewhat to ionic conductivity. The high ionic conductivity of the order of 10−5 Scm1 at 30°C was attained by a crosslinked PEO–LiClO4 complex of [LiClO4]/[EO unit] =0.02.

Polycondensation reactions of diesters having phenolic hydroxyl groups with diamines were carried out in order to investigate the enhancement effect of the phenolic hydroxyl group on the polycondensation. Aromatic hydroxyl diesters derived from salicylic acid or hydroquinone had a higher reactivity toward diamines than the reactivity of ordinary diesters. However, their reactivity was inferior to that of aliphatic hydroxyl diesters such as tartarate. The enhancement effect of the phenolic hydroxyl group was presumed to be due to an interaction of the hydroxyl group with the approaching amine.

The polycondensation reaction of p-aminobenzoic acid with the reagent of triphenylphosphine and hexachloroethane was investigated in order to establish the optimum reaction conditions for direct polycondensation. Reaction conditions, such as the molar ratios of triphenylphosphine and hexachloroethane to the monomer, the concentrations of monomer and reagents, the reaction temperature and the kinds of acid acceptor and solvent, had considerable influence on the yield and the molecular weight of the resulting polyamide. The poly(p-benzamide) having the highest molecular weight was obtained with the molar ratio of triphenylphosphine–hexachloroethane–monomer=1.2 : 1.5 : 1.0 in the mixed solvent of tetramethylurea and pyridine at room temperature.

Couches mono- et multimoleculaires de polymeres amphiphiles formes d'alcool polyvinylique acetalise ayant une chaine laterale lineaire aliphatique de differentes longueurs

A polycondensation reaction of p-aminobenzoic acid occurred at room temperature in the presence of picryl chloride to give polyamide in a quantitative yield. Reaction conditions, solvents, temperatures, concentrations of the monomer, and amount of picryl chloride were investigated. A combination of picryl chloride and pyridine was found to be satisfactory for the polycondensation. A model reaction suggests that the polycondensation reaction proceeds through the formation of an active ester from picryl chloride and carboxylic acid, followed by aminolysis with amino group. The polyamide with the solution viscosity of 1.0 was obtained in quantitative yield under optimum conditions. Polyamides from aromatic dicarboxylic acids and aromatic diamine had lower solution viscosities than that from p-aminobenzoic acid. The reaction mechanism is discussed.

Copolycondensation was carried out through synthesis of copolyamides and copolyesters using a direct polycondensation method with triphenylphosphine derivatives under mild conditions. Aromatic copolyamides and copolyesters were easily obtained with the same copolymer compositions as monomer feed ratios. Polyesteramides were also obtained by the direct copolycondensation method which was influenced by solvents in terms of copolymer compositions. When diaminobisphenol was used as a monomer for the direct polycondensation, either polyamide or polyester was selectively obtained using an appropriate solvent.

Polycondensation and copolycondensation reactions including the formation of nylon 66 occured at room temperature in the presence of triphenyl phosphite and imidazole to give polyamides in a quantitative yield. Reaction conditions including solvents, temperatures and concentration of monomer and catalysts were investigated. A combination of triphenyl phosphite and imidazole was found to be satisfactory for the polycondensation. The polycondensation reaction may proceed through the formation of a mixed anhydride of carboxylic acid and phosphite, followed by aminolysis by amine. Although the yield of poly amide by this synthetic method was almost quantitative, the inherent viscosity of the product did not exceed more than 0.4. The low morecular weight might be due to a termination reaction, e.g., the formation of phosphite amide.

The polycondensation reaction of S, S-dithiocarboxylic acid esters with diamines took place at room temperature to yield polyamide in solution. The reactivity of aromatic S, S-dithioester with aliphatic diamine was higher than that of aliphatic S, S-dithioester and the reaction of S, S-dithioester with aromatic diamine was much slower than that with aliphatic diamine. Solvents greatly influenced the rate of the polycondensation and an inorganic salt such as lithium chloride accelerated the reaction. Polyisophthalamide having an inherent viscosity of 1.06 was obtained in dimethyl sulfoxide in the presence of lithium chloride at 30°C.

Various polythioesters and polythiohydrazides were synthesized by the polycondensation of dithiocarboxylic acid-O,O-diethyl esters with dihydrazides and diols in solution at a relatively low temperature. The polycondensation reaction took place with a much slower rate than that with diamines and the reactivity of dithiocarboxylic acid-O,O-diethyl ester with nucleophiles was in the following order: diamine>dihydrazide>diol.

Diesters or dibasic acids having hetero atoms at positions β to the carbonyl group underwent polycondensation reaction with diamines to form polyamide under mild conditions at relatively low temperature either in solution or in the solid phase. The reactivity enhancement of diesters or dibasic acids due to the introduction of β-hetero atoms could be arranged in the same order of electronegativities: —O—≥—S—>—N=>SO2—>—P=.The effect of these hetero atoms on the reactivity was presumed to be due to the intramolecular interaction between the hetero atoms and the carbonyl group of the ester or acid.

Aromatic and aliphatic dithioamides were synthesized and the polycondensation reaction with nucleophiles such as diamine, dihydrazides or diols was carried out. The polycondensation reaction of dithioisophthalamide (DTI) with hexamethylenediamine (HMD) took place in a good yield at 60°C to form polythioamide with elimination of ammonia. However, the polycondensation rate was found to be much slower than that of dithiocarboxylic acid-O,O-diethyl esters and it took more than a few weeks for completion of the polycondensation reaction. On the other hand, DTI did not react with dihydrazides and diols at all and the reactivity of thioamide toward nucleophiles was inferior to that of dithiocarboxylic acid-O,O-diethyl ester.

Various dithiocarboxylic acid-O,O-diethyl esters were synthesized and the polycondensation reaction with diamines was investigated. The polycondensation reaction of dithiocarboxylic acid-O,O-diethyl esters with hexamethylenediamine(HD) took place at room temperature to form polythioamide in solution in a good yield. The rate of the polycondensation reaction of aromatic dithiocarboxylic acid-O,O-diethyl esters with HD was greatly influenced by solvents, which retarded the rate in the following decreasing order: DMSO>DMF>DMAc>NMP>THF>EtOH>EtOH–H2O(50/50). It was also found that solvents had a strong influence on the structure or the molecular weight of obtained polythioamide and particularly such solvents as DMF, DMAc or DMSO were effective for the formation of a linear and a high-molecular-weight polythioamide, while in ethanol an insoluble polymer with a cross-linked structure was obtained. However, aliphatic O,O-dithioester tended to form an insoluble polymer even in such solvents as DMF, DMAc or DMSO, compared with aromatic O,O-dithioester.

Photo-polymerization and -copolymerization of three aromatic diacrylates, i.e., o−, m−, and p-phenylene diacrylates were investigated in order to elucidate the reactivity of the double bond of α,β-unsaturated carbonyl compounds toward light. Photopolymerizability of p-phenylene diacrylate was highest among these three diacrylates, and it yielded rapidly a cross-linked polymer on irradiation with a high-pressure mercury lamp in tetrahydrofuran solution. Activation energies of photopolymerization of these three diacrylates were much lower than those of thermal polymerization with a radical initiator. Photopolymerization of o-phenylene diacrylate-induced cyclopolymerization, yielding a ladder-type polymer with a high inherent-viscosity.o-Phenylene diacrylate and styrene copolymerized and formed a soluble copolymer on irradiation of light.

Polycondensation of Diethyl Mucate with Hexamethyl-enediamine in the Presence of Poly(4-hydroxystyrene)