Synthesis and characterization of novel polyarylates from 2,5-bis(4-hydroxyphenyl)-3,4-diphenylpyrrole and various aromatic dicarboxylic acids

A new tetraphenylated heterocylic diol, 2,5-bis(4-hydroxyphenyl)-3,4-diphenylpyrrole, was synthesized in three steps starting from 4-methoxydeoxybenzoin. The tetraphenylpyrrole-containing polyarylates having inherent viscosities of 0.28–0.88 dL/g were prepared from the diol and various aromatic dicarboxylic acid chlorides by both phase transfer catalyzed two-phase polycondensation and high temperature solution polymerization methods. All the polyarylates were semi-crystalline, and were readily soluble in a variety of solvents including N-methyl-2-pyrrolidone, m cresol, pyridine, and 1,4-dioxane. These polymers had glass transition temperatures in the range of 223–279°C, with no weight loss below 400°C in both air and nitrogen atmospheres. © 1994 John Wiley & Sons, Inc.     

Synthesis and characterization of new aromatic polyesters and polyethers derived from 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene

New polyarylates and aromatic polyethers were synthesized from 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene, and aromatic dicarboxylic acid chlorides and aromatic dihalides, respectively. The polyarylates having inherent viscosities of 0.28–1.05 dL/g were synthesized by either the two-phase method or the high-temperature solution method. All the polymers were easily soluble in N-methyl-2-pyrrolidone, N,N-dimethylformamide, pyridine, m-cresol, 1,4-dioxane, and 1,1,2,2-tetrachloroethane. They have glass transition temperatures in the range of 217–250°C and showed no weight loss below 315°C in both air and nitrogen atmospheres. Aromatic polyethers with inherent viscosities of 0.85–1.21 dL/g were obtained by the polycondensation of 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene and aromatic difluorides in the presence of potassium carbonate. These polymers having glass transion temperatures of 193–220°C were also soluble in the aforementioned solvents and stable up to around 350deg;C in both atmospheres. © 1994 John Wiley & Sons, Inc.     

Synthesis and properties of a novel perfluorononenyloxy group containing polyarylates

A series of novel perfluorononenyloxy group containing polyarylates were synthesized by a high-temperature solution condensation of 5-(perfluorononenyloxy)-isophthaloyl chloride ( II ) with various aromatic diols in o-dichlorobenzene. All the polyarylates were amorphous and readily soluble in many organic solvents such as o-chlorophenol, o-dichlorobenzene, chloroform, and polar aprotic solvents at room temperature or on heating. Transparent, tough, and flexible films of these polymers could be cast from the o-chlorophenol solutions. The polymers having inherent viscosity of 0.61–1.63 dL/g were obtained in quantitative yields. These polymers were thermally quite stable. The glass transition temperatures of these polyarylates were in the range of 219–242°C by DSC and 224–251°C by DMA, and the 10% weight loss temperatures in nitrogen and air were above 415 and 397°C, respectively. Moreover, these polymers maintained good mechanical properties (G′ ∼ 10⁸ Pa) up to 220°C and had lower moisture absorption than common polyarylates. The dielectric constants of these polymers ranged from 3.23 to 3.75. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 645–653, 1998     

Synthesis of soluble polyarylates with a propeller-like structure via Diels-Alder reaction

Soluble propeller-like polyarylates with M¯_n ≈ 1 × 10⁴ and melting in the range 200–220°C were synthesized via one-pot simultaneous Diels-Alder (using anthracene or (E,E)-1,4-diphenylbutadiene as enophile and the fumaroyl moiety as dienophile) and polycondensation reaction. Thermal properties of all polyarylates were evaluated. Decomposition occurs in two steps between approximately 300–400°C. The first step is due to retro-Diels-Alder reaction and the second one to main-chain decomposition.     

Preparation and properties of fluorine-containing polyarylates from tetrafluoroisophthaloyl chloride and bisphenols

Fluorine-containing polyarylates having inherent viscosities of 0.2–0.8 dL/g were prepared from tetrafluoroisophthaloyl chloride and various bisphenols by low temperature solution polycondensation in chloroform with triethylamine or by two-phase polycondensation in a dichloromethane-water or nitrobenzene-water system with benzyltriethylammonium chloride as the phase transfer catalyst. These polyarylates were amorphous and were readily soluble in various solvents, including chloroform and N-methyl-2-pyrrolidone. The glass transition temperature of the polymer derived from 2,2-bis(4-hydroxyphenyl) propane was 150°C. These polyarylates started to lose weight around 350°C in an air or nitrogen atmosphere.     

Preparation and properties of polyarylates both from 2,2′-bibenzoyl chloride and bisphenols and from biphenyl-2,2′-diol and aromatic dicarboxylic acid chlorides

Polyarylates having inherent viscosities up to 1.02 dL/g were synthesized both by the phase-transfer catalyzed two-phase polycondensation of 2,2′-bibenzoyl chloride with various bisphenols and by the high-temperature solution polycondensation of biphenyl-2,2′-diol with aromatic dicarboxylic acid chlorides. All the polyarylates were amorphous and soluble in a variety of organic solvents including N,N-dimethylformamide, N-methyl–2-pyrrolidone, chloroform, m-cresol, and pyridine. Transparent and flexible films of these polymers could be cast from the chloroform solutions. These polyarylates had glass transition temperatures in the range of 120–250°C and began to lose weight at around 380°C in air. © 1992 John Wiley & Sons, Inc.     

Preparation and properties of polyarylates from 5-t-butylisophthaloyl chloride and various bisphenols

Polyarylates containing a t-butyl pendant group were prepared from 5-t-butylisophthaloyl chloride and various bisphenols through the phase-transfer catalyzed two-phase polycondensation. The polyarylates having inherent viscosities up to 3.1 dL/g were obtained quantitatively. They were readily soluble in various solvents such as chloroform, m-cresol, and pyridine. Coloreless, transparent, and flexible films could be cast from the chloroform solutions of the polymers. The polyarylates had glass transition temperatures between 210 and 320°C, and did not lose weight below 350°C, with 10% weight loss being recorded at 395–450°C in air.     

Synthesis and characterization of aromatic polymers containing pendant silyl groups. I. Polyarylates

Polyarylates containing pendant silyl group were prepared by the phase-transfer catalyzed, two-phase polycondensations of 2,2-bis (4-hydroxyphenyl) propane with corresponding dicarbonyl chlorides such as 2-trimethylsilylterephthaloyl chloride, 5-trimethylsilylisophthaloyl chloride, 5-dimethylphenylsilylisophthaloyl chloride, and 5-triphenylsilylisophthaloyl chloride. The resulting amorphous polyarylates with glass transition temperatures of 163–214°C had inherent viscosities in the range of 0.41–0.95 dL/g. These polyarylates were readily soluble in common chlorinated hydrocarbons and it was possible to obtain transparent, flexible, and tough films from the polymer solutions. The prepared polyarylates showed fairly good thermal stabilities as well as tensile strengths, i.e., the tensile strengths of the cast films from chloroform solution were 6.0–6.7 kg/mm². And TGA data revealed 10% weight losses and residual weights at 800°C were 437–495°C and 27–40% under nitrogen atmosphere, respectively. © 1992 John Wiley & Sons, Inc.     

Synthesis and electrochromism of novel organosoluble polyarylates bearing triphenylamine moieties

A series of novel aromatic polyarylates with triphenylamine units in the main chain and as the pendent group were prepared from the dicarboxylic acid monomer, N,N‐bis(4‐carboxyphenyl)‐N′, N′‐diphenyl‐1,4‐phenylenediamine (1), and various bisphenols. These polyarylates were amorphous and readily soluble in common organic solvents. They had excellent levels of thermal stability associated with moderately high T_g values (182–263 °C). These polymers exhibited strong UV–vis absorption bands at 357–360 nm in toluene solution and the photoluminescence spectra showed maximum bands around 493–503 nm in the green region. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the polyarylates exhibited two reversible oxidation redox couples in acetonitrile solution at E_onset 0.77–0.79 V and 1.12–1.14 V, respectively. The typical polymer 3b film revealed good stability of electrochromic characteristics, with color change from colorless to green and blue at applied potentials ranging from 0.00 to 1.24 V. These anodically polymeric electrochromic materials not only showed excellent reversible electrochromic stability with good green coloration efficiency (CE = 159 cm²/C) and blue coloration efficiency (CE = 154 cm²/C) but also exhibited high contrast of optical transmittance change (ΔT%), 54% in 895 nm for green color and up to 84% in 595 nm for blue color. After over 100 cyclic switches, the polymer films still exhibited excellent stability of electrochromic characteristics. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2004–2014, 2007     

Synthesis and properties of aramids and polyarylates having perfluoro-substituents on the benzene ring

A new series of 16 aramids and 16 polyarylates having perfluoro-substituents on the benzene ring was prepared by a low temperature solution or an interfacial polycondensation. The effects of fluorine substituents on the structure and properties of polymers were examined. Fluorinated aramids exhibited higher crystallinity, while fluorinated polyarylates show lower crystallinity. The melting point (T_m) of aramids decreased with fluorine substitution, whereas T_m of polyarylates from fluorinated aromatic diols was higher than that of those from unfluorinated ones. The temperature of 10% weight loss and the residue at 900°C decreased with fluorine substitution except for the aramids from fluorinated diamines. Solubility and contact angle also increased with fluorine substitution. Some polyarylates were found to exhibit an optical anisotropy.     

Preparation and properties of polyarylates and copolyarylates from phenylindanedicarbonyl chloride and bisphenols

A series of polyarylates having inherent viscosities of 0.4–1.1 dL/g was prepared by the two phase polycondensation of 1,1,3-trimethyl-3-(4-chloroformylphenyl)indanecarbonyl chloride with various bisphenols in an organic solvent–aqueous alkaline solution system in the presence of a phase transfer catalyst. Similarly, copolyarylates of high molecular weights were prepared from a mixture of the phenylindanedicarbonyl chloride, terephthaloyl chloride, and 2,2-bis(4-hydroxy-phenyl)propane. All the polyarylates were characterized by their amorphous nature and high solubility in organic solvents. They gave transparent and tough films by the solution casting. The films had tensile strength of 33–46 MPa, elongation at break of 3–16%, and tensile modulus of 1.2–1.6 GPa. These polyarylates had glass transition temperatures in the range of 205–310°C, and began to decompose at ca. 350°C in air.     

Synthesis and properties of new polyarylates from 1,4‐bis(4‐carboxyphenoxy)naphthyl or 2,6‐bis(4‐carboxyphenoxy)naphthyl and various bisphenols

New 1,4‐naphthyl and 2,6‐naphthyl‐containing polyarylates having inherent viscosities up to 1.28 dL/g were synthesized by the high‐temperature solution polycondensation from the acid chloride of 1,4‐bis(4‐carboxyphenoxy)naphthyl or 2,6‐bis(4‐carboxyphenoxy)naphthyl and various bisphenols. Most of the resulting polyarylates showed amorphous characteristics and were readily soluble in common organic solvents such as N,N‐dimethylacetamide (DMAc), N‐methyl‐2‐pyrrolidone (NMP), o‐chlorophenol, and chloroform. Transparent, flexible, and colorless films of these polymers could be cast from the DMAc solutions. Their cast films had tensile strengths ranging from 54.9 to 84.2 MPa, elongations at break from 5.3% to 19.0%, and initial modulus from 2.0 to 2.8 GPa. These polymers had glass transition temperatures in the range of 172–280°C and began to lose weight around 400°C, with 10% weight loss being recorded at about 450°C in air. Dynamic mechanical analysis (DMA) reveals that the polyarylates containing isopropylidene linkages have three transitions on the temperature scale between −100 and 300°C. However, only two transitions were observed in the other polyarylates without isoproylidene linkage. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 645–652, 1999     

Lithographic design of photosensitive polyarylates based on reaction development patterning

The factors affecting pattern‐forming properties in reaction development patterning were examined with polyarylates with various bisphenol moieties. The developability of the photosensitive polyarylates was dependent on the properties of the subtituent (R) in the bisphenol moieties. The development time decreased in the following order: R?C(CH₃)₂ > fluorenyl unit ? phenolphthalein unit > C(CF₃)₂ > SO₂. This order agreed with that of the reactivity between the polyarylates and ethanolamine, and these orders can be explained by pK_a of the bisphenol used to prepare the polyarylates. The development with NH₂? R′? OH resulted in successful positive‐tone pattern formation. However, pattern formation with the developers containing NH₂? R′? OCH₃ was unsuccessful. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2694–2706, 2006     

Synthesis and properties of mesogenic laterally fluorinated compounds containing benzoxazole unit

Series of mesogenic laterally fluorinated compounds, 2-(2′,3′-difluoro-4′-alkoxybiphenyl-4-yl)-benzoxazole derivatives (nB-Fx) bearing different substituents (H, CH₃, Cl, NO₂, coded as nB-FH, nB-FM, nB-FC and nB-FN, respectively) at 5-position, were prepared and characterised. Their phase transition behaviour was investigated by differential scanning calorimetry and polarising optical microscopy. nB-Fx with alkoxy chain lengths of 2 to 10 carbons exhibited enantiotropic mesophases, for which the mesophase ranges were 0°C–58°C and 0°C–71°C on heating and cooling for nB-FH, 41°C–93°C and 66°C–140°C for nB-FM, 44°C–133°C and 87°C–155°C for nB-FC, and 0°C–76°C and 0°C–95°C for nB-FN, respectively. Compared to non-fluorinated analogues, with the exception of nB-FC, fluorinated nB-Fx mainly exhibited nematic mesophase both in heating and cooling, which were attributed to the disruption of the side-to-side intermolecular packing caused by the two ortho-lateral fluoro substituents. For nB-Fx series, nB-FM, nB-FC and nB-FN exhibited a much wider mesophase range than the corresponding nB-FH series, which indicated that the substituent at benzoxazole moiety was helpful in increasing the mesophase stability. With the exception of nB-FN, the nB-Fx series displayed intense photoluminescence emission at 379–383 nm in methylene chloride solution, when it was excited at its absorption maxima.     

Studies on metathetical and thermal polymerization of 5-norbornene 2,3-dicarboximide end-capped resins Pt-II

The article deals with synthesis, characterization, and polymerization of 5-norbornene-2,3-dicarboximide end-capped resins (bisnadimides) based on 4,4′-diaminodiphenylether, 1,4/1,3-bis(4′-aminophenoxy) benzene, 2,2′-bis[4-(4′-aminophenoxy)phenyl]propane, and bis[4-(4′-aminophenoxy)phenyl]sulphone. Both exo and endo bisnadimides were prepared by reacting the aromatic diamines with exo or endo nadic anhydride in glacial acetic acid at 120°C. The exo or endo bisnadimides could be distinguished on the basis of differences observed in IR or ¹H-NMR spectra. Both thermal (in solid state) and metathetical polymerization (using WCl₆/tetramethyltin catalyst and chlorobenzene solvent) of bisnadimides was carried out. Only exo bisnadimides could be polymerized using metathesis reaction whereas thermal polymerization of both endo and exo bisnadimide could be successfully carried out at 300°C in static air atmosphere. The polymers were highly crosslinked and insoluble in common organic solvents. The polymers obtained by metathesis polymerization were light brown in color whereas those obtained by thermal polymerization were dark brown in color. Thermal stability of the thermally polymerized exo or endo bisnadimides was comparable. These polymers were stable up to 400°C and decomposed in a single step above this temperature. The char yield at 800°C depended on the structure of the polymer and was in the 39–56% range. The polymers formed by metathesis polymerization showed a 1–3% weight loss in the temperature range 226–371°C and decomposed in a single step above 440°C. The char yields were higher in these polymers (53–71%) compared to those obtained by thermal polymerization. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2323–2331, 1997     

Laminating resins obtained from 2,2′-(1,4-phenylenedivinylene)bispyridine bismaleimides and maleimide-terminated styrylpyridine prepolymers

A new bismaleimide (2a) , biscitraconimide (2b) , and bisnadimide (4) were synthesized by reacting 2-amino-6-methylpyridine with an equimolar amount of maleic, citraconic, or nadic anhydride, respectively, and then with a half molar amount of 1,4-benzenedicarbaldehyde in the presence of acetic anhydride. They, as well as the intermediate amic acids ( 1a, 1b, and 3 ) were characterized by IR and ¹H-NMR spectroscopy. The DTA thermograms showed that crosslinking of polymer precursors started at 180–212°C. The crosslinked resins obtained from 2a and 2b were stable up to 300–313°C and afforded anaerobic char yield of 53–60% at 800°C. The cured resin of 4 was less thermostable. In addition, end-capping of styrylpyridine prepolymers was accomplished by reacting 2,6-dimethylpyridine (n mol) with 1,4-benzenedicarbaldehyde (n + 1 mol) in acetic anhydride to yield a formyl-terminated styrylopyridine prepolymer. The latter reacted with the maleamic acid 1a (2 mol) to afford a series of maleimide-terminated styrylpyridine prepolymers MTSOs. They showed lower curing temperatures than did the ordinary poly(styrylpyridine). Their cured resins did not lose weight up to 310–344°C both in N₂ or air and afforded anaerobic char yield of 66-72% at 800°C.     

Synthesis and characterization of new aromatic polyesters and a polyether derived from 2,2-bis(4-hydroxyphenyl)-1,2-diphenylethanone

New polyarylates having benzopinacolone units were synthesized from 2,2-bis(4-hydroxyphenyl)-1,2-diphenylethanone and aromatic dicarboxylic acid chlorides. The polymers having an inherent viscosity of 0.71–0.94 dL/g were obtained by the two-phase method using toluene as an organic solvent. The polymers were easily soluble in various organic solvents and had high glass transition temperatures in the range of 200–240°C. An aromatic polyether having benzopinacolone unit was also prepared. However, its inherent viscosity was low because of the occurrence of a side reaction. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2229–2235, 1998     

Benzocyclobutene in polymer synthesis. I. Homopolymerization of bisbenzocyclobutene aromatic imides to form high-temperature resistant thermosetting resins

A series of new bisbenzocyclobutene-terminated aromatic imide monomers has been synthesized from the condensation reaction of 4-aminobenzocyclobutene and the perspective dianhydride in refluxing acetic acid/toluene. The differential scanning calorimetric studies of the foregoing monomers indicated that polymerization exotherms began at 229–250°C and reached their maxima at 258–263°C. The cured samples (250–254°C; N₂; 8 h) were surprisingly stable toward thermo-oxidative degradation; only 7–10% weight loss was observed after 200 h (in air) at 314°C (600°F). At higher temperatures (650 and 700°F), the most rigid structure was the most thermo-oxidatively stable. An approach to enhance both the final glass-transition temperature (T_g cure) and the thermo-oxidative stability of the bisbenzocyclobutene system was to dilute the cure-site density since the cure-site structure is the weakest part of the polymeric structure. Therefore, a series of bisbenzocyclobutene-terminated aromatic imide oligomers were prepared, using various aromatic amines as the chain-extending agents. Meta-phenylenediamine was apparently the most effective in the advancement of both the T_g (cure) and thermo-oxidative stability.     

Synthesis and characterization of new poly(amide–imide)s from 1,4-bis(4-trimellitimidophenoxy)-2-tert-butylbenzene with various diamines

New poly(amide–imide)s were prepared from a diimide–dicarboxylic acid, 1,4-bis(4-trimellitimidophenoxy)-2-tert-butylbenzene ( BTTB ), with various diamines by the direct polycondensation in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. The new diimide–dicarboxylic acid BTTB containing an ether linkage and tert-butyl substituent was synthesized by the condensation reaction of 1,4-bis(4-aminophenoxy)-2-tert-butylbenzene with trimellitic anhydride. All the polymers were obtained in quantitative yields with inherent viscosities of 0.62–1.06 dL g⁻¹. The polymers were amorphous, and most of them were readily soluble in aprotic polar solvents such as NMP, N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF), as well as in less polar solvents such as dimethyl sulfoxide (DMSO), m-cresol, pyridine, and γ-butyrolactone, and also even in tetrahydrofuran. The glass transition temperatures of the polymers were determined by DSC method, and they were in the range of 238–279°C. These polymers were stable up to 408–449°C in air and 451–483°C in nitrogen and lose 10% weight in the range of 479–525°C in air and 480–528°C in nitrogen atmosphere. The polymer films had a tensile strength range of 71–115 MPa, an elongation at break range of 4–14%, and a tensile modulus range of 2.3–3.1 GPa. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2301–2307, 1998     

New Organosoluble and Optically Transparent Polyamides Containing Xanthene Units and Methyl Pendant Groups From 9,9-Bis[4-(4-carboxyphenoxy)-3-methylphenyl]xanthene

A new aromatic dicarboxylic acid, 9,9-bis[4-(4-carboxyphenoxy)-3-methylphenyl]xanthene (BCAMPX) was prepared from the nucleophilic substitution reaction of 9,9-bis(4-hydroxy-3-methylphenyl)xanthene with p-fluorobenzonitrile, followed by alkaline hydrolysis. Then BCAMPX was polycondensated with various aromatic diamines to afford the polyamides with the number-average molecular weight in the range of 45,300–51,500 and the polydispersity index ranged from 1.67 to 1.85. These polyamides showed glass transition temperatures between 260–286°C and 10% weight loss temperatures ranging from 490 to 504°C and 480 to 490°C in nitrogen and air respectively, and char yields above 52% at 800°C in nitrogen. Nearly all polyamides were readily soluble polar aprotic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide (DMAc), tetrahydrofuran and pyridine, and afforded transparent, strong and flexible films upon casting from DMAc solvent. All polyamides were amorphous and exhibited tensile strengths of 80–91 MPa, elongations at break of 9–13%, and initial moduli of 1.95–2.82 GPa, as well as low moisture absorption in the range of 2.65–3.65%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 360–378 nm range.