Preparation of polyamide-imides via the phosphorylation reaction. II. Synthesis of wholly aromatic polyamide-imides from N-[p-(or m-) carboxyphenyl]trimellitimides and various aromatic diamines

Wholly aromatic polyamide-imides with high molecular weight (η_inh up to 1.7 dL/g in DMAc–5% LiCl) were obtained by the direct polycondensation reaction of N-[p-( or m-) carboxyphenyl]trimellitimide [p-(or m-)CPTMI] and aromatic diamines by means of di- or triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)-pyridine solution in the presence of lithium or calcium chloride. The factors affecting the phosphorylation reaction were investigated, in particular for the reaction of p-CPTMI and 4,4'-oxydianiline (ODA). Molecular weight of polymers varied with the amount of metal salts and showed maximum values at the concentration of 10-15 wt % in the reaction mixture. Monomer concentration of 0.2 mol/L produced polymer of the highest viscosity. Higher concentrations produced gelation and yielded polymers of low molecular weight. A reaction temperature of about 120°C gave the best results. Among the solvents tested, NMP was significantly the most effective for the reaction. The highest inherent viscosity values, η_inh = 1.35 and 1.58 dL/g, were obtained with triphenyl phosphite (TPP)/monomer and diphenyl phosphite (DPP)/monomer molar ratios of 2.0. Excessive addition of phosphites did not cause a serious deleterious effect on the molecular weight of polymer. Polycondensations of several combinations of p-or m-CPTMI and aromatic diamines were carried out with satisfactory results.     

Preparation of sulfonyl aromatic polyamides and copolyamides by means of di- or triphenyl phosphite

High molecular-weight aromatic polyamides were obtained by the direct polycondensation reaction of 4,4′-sulfonyldibenzoic acid (SDA) with various aromatic diamines, by means of di- (DPP) or triphenyl phosphite (TPP) in N-methyl-2-pyrrolidone (NMP)-pyridine solution containing metal salts such as LiCl and CaCl₂. The factors affecting the phosphorylation reaction were investigated, in particular for the reaction of SDA and 4,4′-oxydianiline (ODA). For the polymerization by means of TPP, the optimum conditions are: molar ratio of TPP to diacid, higher than 2.3; concentration of metal salts, 8 wt % LiCl or 6 wt % CaCl₂; reaction temperature, 100°C; and monomer concentration, 0.4 mol/L. For the polymerization by means of DPP, the optimum conditions are: molar ratio of DPP to diacid, higher than 3.8; concentration of metal salts of 8 wt % LiCl or 10 wt % CaCl₂; reaction temperature, 110°C; and monomer concentration, 0.4 mol/L. Copolyamides were also prepared from the reaction of ODA with the mixed diacids of SDA and other dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalene dicarboxylic acid by using TPP and DPP as the condensing agents.     

Thermotropic homopolyesters. III. Preparation and properties of polymers based on 4′-hydroxyphenyl-4-hydroxycinnamate

Low-molecular-weight 4′-acetoxyphenyl-4-acetoxyoinnamate, as well as several polyesters synthesized from this monomer and aliphatic dibasic acids, exhibit thermotropic nematic phases. DSC heating curves for all of the polymers exhibit multiple transitions. The amount of crystallinity of these polymers at room temperature is small and the degree of order along the chain axis in the crystalline phase is poor. For the lower homologues the nematic phase exists over a broad temperature range of approximately 100°C. The polyester from chiral (+)-3-methyl adipate forms a thermotropic cholesteric phase. Both the diacetoxy monomer and azelate polymers of low molecular weight adopt the homeotropic texture on glass slides, but with increasing molecular weight the planar texture becomes preferred. Investigation of the effects of electric fields in the conduction regime upon the nematic phase of the diacetoxy monomer revealed that Williams domains are formed only with difficulty. In most cases, a stationary pattern appeared instead. At higher voltage the dynamic scattering mode (DSM) was obtained, and above this a field-induced transition to the isotropic phase. The azelate polyesters exhibited Williams domains and the DSM in the conduction regime. The formation time for Williams domains was fairly short for polymers having η_inh < 0.44 dL/g, but increased to 80 min when η_inh = 0.68 dL/g. The DSM was only observed for polymers having η_inh < 0.61 dL/g. For these polymers the critical frequency separating the conduction and dielectric regimes exhibits a stronger temperature dependence than that of low-molecular-weight nematogens. A new instability pattern is reported for the azelate polyesters in the dielectric regime.     

Studies on reactions of the N-phosphonium salts of pyridines. XIV. Wholly aromatic polyamides by the direct polycondensation reaction by using phosphites in the presence of metal salts

Poly-p-benzamide of high molecular weight (η_inh = ～ in H₂SO₄) was obtained by the direct polycondensation reaction of p-aminobenzoic acid (p-ABA) by means of diphenyl and triaryl phosphites in N-methylpyrrolidone (NMP)-pyridine solution containing lithium and calcium chlorides. Molecular weight of polymer varied with the amount of these salts, showing maximum values at the concentration of about 4 wt-% of LiCl or about 8 wt-% of CaCl₂ in the reaction mixture. The reaction temperature at around 80°C gave a polymer of the highest viscosity. The polycondensation reaction was also affected by monomer concentration, solvents, and tertiary amines like pyridine. Similarly, aromatic polyamides with high molecular weight (η_inh values up to 1.34 in H₂SO₄) were prepared from isophthalic acid and aromatic diamines, whereas terephthalic acid gave only low-viscosity polymers.     

Synthesis and characterization of new AB-type poly(etherimide)s containing bisphenol moieties

A series of new AB-type poly(etherimide)s having bisphenol-type moiety was prepared by the one-pot polyimidization using triphenylphosphite(TPP) in N-methyl-2-pyrrolidone(NMP)/pyridine solution at 150°C. Complete cyclodehydration was observed in the polymerizations as well as in model reactions. Polymers were obtained with inherent viscosities in the 0.27–0.49 dL/g range. The M_n and M_w/M_n of poly[4-(1,4-phenyleneoxy-1,4-phenylenehexafluoro-isopropylidene-1,4-phenylene)oxyphthalimide] (4d) with η_inh = 0.49 dL/g were 73,400 g/mol and 1.5, respectively. Most polymers could readily be dissolved in common organic solvents such as DMAc, NMP, and m-cresol. The polymer 4d was soluble even in chloroform. These polymers had glass transition temperatures between 205 and 235°C, and 5% weight loss temperatures in the range of 511–532°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3530–3536, 1999     

Synthesis of trans‐4‐hydroxy‐L‐proline‐based telechelic prepolymers and poly(ester‐urethane)

The synthesis of hydroxyproline‐based telechelic prepolymers by the condensation polymerization of trans‐4‐hydroxy‐N‐benzyloxycarbonyl‐L ‐proline methyl ester was investigated. All the polymerizations were carried out in the melt with stannous octoate as the catalyst and with different diols. The products were characterized by differential scanning calorimetry, proton nuclear magnetic resonance, infrared spectrophotometry, and inherent viscosity (η_inh). According to the analytic results, the η_inh value of the prepolymers depended on the kind and amount of diols that were added. With an increase in the 1,6‐hexanediol feed from 2 to 10 mol %, there was a decrease in η_inh from 0.78 to 0.41 along with a decrease in the glass‐transition temperature (T_g ) from 63 to 42 °C. When 2 mol % of different kinds of diols were used, η_inh ranged from 0.78 to 0.21, and T_g varied from 70 to 43 °C. These new prepolymers could be linked to poly(ester‐urethane) by the chain extender 1,6‐hexamethylene diisocyanate. The poly(ester‐urethane) was amorphous, and the T_g was 76 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2449–2455, 2000     

Synthesis of novel phosphinic acid-containing polymers

Three arylene difluoride monomers containing phosphine oxide ( 1 ), phosphinic acid ( 2 ), or phosphinate ester ( 3 ) groups were prepared and polymerized with bisphenol A to give novel poly-(arylene ether)s ( 4 , 5 , and 6 ). The polymers obtained had moderate molecular weights (η_inh: 0.14–0.30 dL g⁻¹ in N-methylpyrrolidinone) and glass-transition temperatures (T_g: 102–200 °C), depending on the phosphine group in the main chain. Using bis(4-fluorophenyl)sulfone as a comonomer improved the polymerization to give copolymers with higher solution viscosities. The stoichiometric investigation revealed that 7 mol % excess of fluoride monomer gave the highest molecular weight copolymer 8 with η_inh of 0.78 dL g⁻¹, which had a T_g of 176 °C, a T of 432 °C, and formed a hard film by casting from solution. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1854–1859, 2001     

High-molecular-weight poly(p-phenyleneterephthalamide) by the direct polycondensation reaction with triphenyl phosphite

Poly(p-phenyleneterephthalamide) of high molecular weight was obtained when the polycondensation of terephthalic acid and p-phenylenediamine was carried out in N-methylpyrrolidone (NMP) that contained dissolved CaCl₂ and LiCl in the presence of pyridine. The molecular weight of the polymer obtained varied with the amount of pyridine relative to the metal salts and with the molar ratios of CaCl₂ to LiCl, the maximum η_inh value of 4.5 being obtained under the conditions Py/(CaCl₂ + LiCl) ≈ 2.5 (mol/mol), CaCl₂/LiCl ≈ 1.2 (mol/mol), and LiCl + CaCl₂ ≈ 4 g. Among the solvents tested, NMP was significantly effective for the reaction. Polycondensations of several combinations of other dicarboxylic acids and diamines were carried out with limited success.     

Ionic conduction in LiScn/Dimethylformamide/Poly(propylene oxide) system II. Mobility of lithium and thiocyanate ions

Ionic conductivity σ, shear viscosity η, and glass transition temperature T_g were measured on systems composed of lithiumthiocyanate LiSCN, N,N-dimethylformamide (DMF), and poly (propylene oxide) (PPO) over wide ranges of LiSCN concentration C and DMF content Φ. Using the dissociation constant of LiSCN reported in Part I, we have determined the concentration n of Li⁺ and SCN^? ions and then the mobility μ from σ. Data indicate that in the binary system of LiSCN/PPO, the σ versus C curve exhibits a maximum ca. C = 0.3 mol/L. In low C range, μ is independent of C but decreases with C in the range of C > 0.3 mol/L. Similar n dependence of μ is seen in the ternary systems containing DMF. The ratio of μ₀/μ (C) is lower than the ratio of viscosity η(C)/η₀ where μ₀ and η₀ indicate the values at infinite dilution of LiSCN. Thus the friction coefficient ?_ion for the translational diffusion of the ions is not proportional to the macroscopic viscosity. Relationship between μ and the monomeric friction ?_p for the segmental motion of the PPO chains is also discussed based on the data of T_g and the Williams-Landel-Ferry equation. ©1995 John Wiley & Sons, Inc.     

Nematogenic block copolymers via the yamazaki reaction

A novel extension of the Yamazaki reaction is used to prepare block copolymers having rigid blocks of poly-(p-benzamide) (PBA) and semiflexible blocks of polyamide-hydrazide. A PBA prepolymer having M ? 10,000 was synthesized by the usual Yamazaki reaction using triphenylphosphite. As previously reported, higher-molecular-weight PBA could be obtained using 4-N-(4′-aminobenzamido)benzoic acid containing a preformed amide linkage. Addition of p-aminobenzhydrazide and terephthalic acid then led to formation of the polyamide-hydrazide blocks using as the active reactant the diphenylphosphite formed as a by-product in the first polymerization. Evidence that a block copolymer is produced includes an increase in inherent viscosity during the second step, differences in the solubility of the copolymer compared to the homopolymers, and comparison of the phase diagram of the block copolymer in N-methylpyrrolidone having 4% added LiCl with those of a random copolymer, and of mixtures of the two homopolymers. The critical concentration required to form a nematic phase in solutions of the block copolymers is correlated with the length (or axial ratio) of the rigid block, and with its proportion in the copolymer.     

Synthesis of hydrogen-terminated aliphatic bis(ethynyl ketone)s and aliphatic poly(enamine-ketone)s and poly(enonesulfide)s

Hydrogen-terminated aliphatic bis(ethynyl ketone)s (H-ABEKs): 1,9-decadiyne-3,8-dione ( 3a ) and 1,13-tetradecadiyne-3,12-dione ( 3b ) were prepared by the Friedel-Crafts reaction of bis(trimethylsilyl) acetylene (BTMSA) with adipoyl chloride and sebacoyl chloride, followed by desilylation with an aqueous buffer solution. Aliphatic poly(enamine-ketone)s (APEKs) and aliphatic poly(enonesulfide)s (APESs) were prepared in nearly quantitative yield by the nucleophilic addition polymerization of 3a,b with various diamines and dithiols in N,N-dimethylformamide (DMF) and m-cresol at room temperature during 14-22 h. Aromatic diamines and dithiols gave polymers that were soluble only in m-cresol. Primary diamines gave exclusively APEKs with the cis (Z) configuration. Dithiols gave APESs which contained more cis (Z) than trans (E) configurations. The inherent viscosities (η_inh) of the APEKs ranged from 0.05 to 0.73 dL/g. The APESs gave η_inh ranging from 0.36 to 2.21 dL/g.     

Study of synthesis and properties of tetrafluoroethylene–propylene copolymers

Bulk copolymerization of tetrafluoroethylene (TFE) with propylene (P) initiated by tert-butyl peroxybenzoate (TBPB) in the temperature interval 323–363 K, monomer pressure from 2 to 9 MPa, and TFE and P molar ratio from 20/80 to 90/10 was carried out. The effect of these reaction conditions on the yield, molecular weight, and polymer composition of the copolymer synthesized was studied. Rubber-like alternating copolymers in a wide range of monomer compositions of TFE and P (from 40 to 80 mol %) were obtained. The reaction proceeds in a stationary state without an induction period. Monomolecular chain transfer reaction (C_p = 5 × 10^?4) to propylene takes place. The relative reactivity ratio of P and TFE (0.15 and 0.01, respectively) and apparent activation energy E_α = 75.8 kJ/mol of the reaction were determined.     

Synthesis and characterization of polyamides derived from (4-(4-(2, 6-diphenylpyridin-4yl)phenoxy)phenyl)-3, 5-diaminobezamide

New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,¹H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N₂.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_max in the range of 470-550 nm.     

Hydroxyoxo(5,10,15,20-tetraphenylporphinato)tungsten(V) as a receptor for foodstuff and drug components. Thermodynamics of supramolecular complexation

The thermodynamics of stepwise reactions of hydroxyoxo(5,10,15,20-tetraphenylporphinato)tungsten(V) (O=W(OH)TPP) with biologically active base molecules was studied. For the reaction of O=W(OH)TPP with benzimidazole, four steps were found and studied; the equilibrium constants K _n were determined to be 2.55 × 10⁴, 1.87 × 10³ L/mol, 1.06 × 10⁶, 4.09 × 10⁴ L²/mol². The reaction of O=W(OH)TPP with pyrazine was a one-step reversible process of Pyz coordination to the eighth coordination site (K = 399 L/mol). The correlation equations relating the stability of supramolecular complexes to pK of the bases were obtained. The thermodynamic data were used to demonstrate the prospects of applying the metal porphyrin as a receptor for N-bases in membranes, sensors, and analytical devices for quality control of foodstuffs, drugs, and gas mixtures for the content of VOCs.     

Fluorescence study on a liquid‐crystalline polyester containing naphthoate mesogen units

Using fluorescence spectroscopy, we investigated intermolecular interaction between mesogenic units in a thermotropic main‐chain LC polyester, P(HBA73/HNA27), containing oxybenzoate (HBA) and oxynaphthoate (HNA) mesogenic units. It is known that P(HBA73/HNA27), which has a high molecular weight, shows second harmonic generation (SHG) activity. P(HBA73/HNA27) showed fluorescence at 410 nm and 430 nm, originating from two kinds of intermolecular interaction. Fluorescence with a peak at 410 nm comes from the ground‐state complex between partially overlapping naphthoate units or between naphthoate and oxybenzoate units whose interaction is weak. Fluorescence at 430 nm comes from the ground‐state complex between fully overlapping naphthoate units whose interaction is strong. The relative fluorescence intensity for 430 nm compared to 410 nm increases with increases in inherent viscosity, η_inh, of P(HBA73/HNA27), the composition ratio of HNA/HBA, and temperature. The fluorescence intensity ratio, I₄₃₀/I₄₁₀, of P(HBA73/HNA27) shows the same inherent‐viscosity dependence with its sudden increase at η_inh = 1.4 ∽ 2.2 dL/g as its SHG activity does, supporting the polar structure and uniformity of LC orientation of the present LC polyester. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2922–2928, 2000     

Synthesis and Characterization of Novel Biodegradable Polyamides Containing α-amino Acid

The polyamides were obtained from 1,6-hexanediamine and diacylchloride which incorporated α -amino acid residues through interfacial polycondensation. High molecular weight (η_inh = 1.05–1.18 dL/g) polymers were produced with high yields. The structure of polyamides was verified by FT-IR and ¹H NMR spectra. They showed a remarkable ability to develop high crystallinity with melting temperatures in the range 117–191°C and was stable up to 350°C under nitrogen. Two methods such as alkali hydrolysis (10% NaOH w/v, 80°C) and enzymatic hydrolysis were employed for assessing the susceptibility of these polyamides to degradation. A preliminary investigation of the 5-fluorouracil (5-FU) release characteristics of these polyamides showed that the release rate increased with increasing water absorption of the polymers.     

Syntheses of polyarylates by alcoholysis and esterolysis

The synthesis of polyarylates containing dimethyl 2,6-naphthalenedicarboxylate (DMNDC), an industrially available, readily purified, and tractable monomer, was investigated by using two synthesis routes, namely alcoholysis and esterolysis in the presence of tin catalyst. Diphenyl ether was used as solvent to keep the co-reactants in solution and to ensure stoichiometric balance. The polyarylates from dimethyl isophthalate (DMI)/dimethyl terephthalate (DMT)/bisphenol-A (BPA) or DMI/DMNDC/BPA were synthesized by alcoholysis in a two step process. A two step esterolysis process was used to synthesize high molecular weight polyarylate starting from DMI/DMT/bisphenol-A diacetate (BPAOAc) or DMI/DMNDC/BPAOAc ([η]_inh = 0.48 dL g⁻¹). Simplification to a one step esterolysis reaction led to a high molecular weight polyarylate ([η]_inh = 0.48 dL g⁻¹) starting from the mixture DMI/DMNDC/BPAOAc. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2891–2897, 1999     

Synthesis of polyurea by direct polycondensation of 4-aminophenyl ether with lithium carbonate

Polyureas of high molecular weight were obtained by the direct polycondensation of 4-aminophenyl ether with lithium carbonate in the presence of triphenylphosphine (Ph₃P), hexachloroethane (C₂Cl₆), and pyridine. Reaction conditions, such as the molar ratios of Ph₃P and C₂Cl₆ to the monomers, monomer concentrations, reaction temperatures, reaction times, and kind of solvents, had a significant effect on the yield and the molecular weight of the resulting polyureas. The polyurea having the highest solution viscosity of 0.91 dL/g was obtained with the molar ratio of Ph₃P/C₂Cl₆/monomers = 2.4/2/1 in the mixed solvent of N-methyl-2-pyrrolidone and pyridine at 80°C.     

Synthesis and Characterization of Poly(Methyl Methacrylate) Grafted from Acacia Gum

Graft polymerization of methyl methacrylate onto acacia gum has been studied in detail. The grafting was found to be optimal under the following reaction conditions: gum at 0.4 g/dL, monomer at 7.52 × 10^?;2 mol/dL, ceric ammonium sulfate at 15.81 × 10^?;4 mol/dL, H₂SO₄ at 0.037 mol/dL, temperature at 50 °C and time at 3.0 h. Fourier transform infrared spectroscopy was sed for the confirmation of grafting. Thermal and physical properties of the copolymer were studied. A probable mechanism of polymerization has been suggested based on reaction kinetics.     

Novel heterocyclic poly(arylene ether ketone)s: Synthesis and polymerization of 4‐(4′‐hydroxyaryl)(2H)phthalazin‐1‐ones with methyl groups

Based on green chemistry, a simple and efficient direct synthesis of 4‐(4′‐hydroxyaryl)(2H)phthalazin‐1‐ones ( 2a–2f ) was developed in a two‐step reaction, in which the Friedel–Crafts acylation reaction of six phenols with phthalic anhydride was initially carried out and then followed by cyclization with hydrazine hydrate in good to excellent yields with high regioselectivity. A number of novel heterocyclic poly(arylene ether ketone)s were prepared conveniently from several unsymmetrical, twist, and noncoplanar phthalazinone‐containing monomers ( 2a–2f ) and an activated difluoro monomer via a N? C coupling reaction. It was very interesting that the obtained monomers and polymers exhibited diverse properties with the variation of the number and location of the substituted methyl groups. All these polymers had a high molecular weight with M_n and η_inh in the range of 44,960–169,000 Da and 0.38–0.79 dL/g, respectively. Actually, the obtained polymers displayed excellent thermal properties with T_g's ranging from 222 to 248 °C and 5% weight loss temperatures in nitrogen higher than 430 °C. Moreover, these polymers were readily soluble in common organic solvents, such as N‐methyl‐2‐pyrrolidone, chloroform, pyridine, and m‐cresol, and could be cast into flexible and colorless or nearly colorless films by spin‐coating or casting processes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1525–1535, 2007