Poly(arylene sulfides) with pendant cyano groups as high-temperature laminating resins

Poly(phenylene sulfides) were synthesized from m-benzenedithiol and aromatic dibromides in a basic medium of potassium carbonate in dimethylformamide or dimethylacetamide. The products obtained were slightly off-white with relatively low melting ranges and had inherent viscosities in the 0.2–0.4 dl/g range in hexamethylphosphoric triamide. Similar poly(phenylene sulfides) containing pendant cyano groups along the polymer chains were obtained by the use of 5 mole-% of either 2,4-dichlorobenzonitrile or 3,5-dichlorobenzonitrile. The products were similar to the pure polyphenylene sulfides, except that they showed lower melting ranges and gave insoluble products when heated alone or in the presence of zinc chloride.     

Aromatic polyethers,polysulfones, and polyketones as laminating resins. VI. Polymers from 2,5-dicyanoterephthalic acid

Aromatic poly(keto ether sulfones) containing various amounts of pendant cyano groups were synthesized from 1,4-bis(p-phenoxybenzoyl)-2,5-dicyanobenzene, 1,3-bis(p-phenoxybenzenesulfonyl)benzene, and isophthaloyl chloride by a Friedel-Crafts type polymerization. These polymers softened at 160–190°C and had inherent viscosities of 0.44–0.61 in hexamethylphosphoric triamide. Crosslinkings were made by heating the polymers alone or in the presence of zinc chloride at 360–370°C to give black resinous materials that were insoluble in hexamethylphosphoric triamide in which the original polymers dissolved quite readily.     

Synthesis and properties of new polyamides derived from 2,2‐bis[4‐[2‐(4‐aminophenoxy)ethoxy]phenyl]sulfone by direct polycondensation

A series of new polyamides containing both sulfone and oxyethylene moieties in the polymer chain was prepared by the direct polycondensation of the diamine monomer 2,2‐bis[4‐[2‐(4‐aminophenoxy)ethoxy]phenyl]sulfone (BAEPS) and various aromatic dicarboxylic acids in N‐methyl‐2‐pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. Polymers were produced with inherent viscosities of 0.30–0.60 dl/g and identified by elemental analysis, and infrared and nuclear magnetic resonance spectra. Most of the polymers were readily dissolved in polar solvents such as NMP, dimethylsulfoxide, N,N‐dimethylacetamide, N,N‐dimethylformamide and m‐cresol at room temperature. Polymers containing rigid and symmetric p‐phenylene, naphthalene and p‐biphenylene moieties revealed a crystalline nature and showed no solubility in organic solvents. These polyamides had 10% weight loss temperatures ranging between 423 and 465 °C in nitrogen atmosphere and glass transition temperatures between 170 and 305 °C. The polymers with crystallinity nature exhibited melting endotherms (T_m) below 386 °C in differential scanning calorimetry trace. Copyright © 1999 John Wiley & Sons, Ltd.     

Synthesis and properties of liquid crystalline polyurethanes

1,4-Bis(p-hydroxybenzoate)phenylene was prepared using 1,4-bis(trimethylsiloxy)benzene and p-hydroxybenzoyl chloride as starting materials. A series of novel 1,4-bis(p-hydroxyalkoxybenzoate)phenylene were synthesized by reaction of 1,4-bis(p-hydroxybenzoate) phenylene with 3-brompropanol and 4-bromobutanol, respectively. The liquid crystal polyurethanes were prepared by 1,4-bis(p-hydroxyalkoxybenzoate)phenylene with MDI (p-methylene diphenylenediisocyanate) and 2,4-TDI(2,4-toluenediisocyanate), respectively. The thermotropic properties, the melting point (T _m) and the isotropization temperature (T _i) of the synthesized polyurethanes were characterized by DSC, IR and POM. It showed that all of the polyurethane polymers exhibited thermotropic liquid crystalline properties between 144°C and 260°C. The transition temperature (T _m and T _i) decreased with an increase in the length of the methylene spacer. __________ Translated from Journal of Qingdao University of Science and Technology, 2006, 27(1) (in Chinese)     

Synthesis of polysulfone-sulfides by polyadditions of dithiols to divinyl sulfones

Polyadditions of 1,6-hexanedithiol and 1,10-decanedithiol to divinyl sulfone (DVS) in hexamethylphosphoramide in the presence of triethylamine or potassium fluoride afforded polysulfone-sulfides (IIIa and IIIb) with inherent viscosities as high as 0.8 dl/g. Polymerizations of other dithiols with DVS and distyryl sulfone (DSS) were also carried out, however, only low-molecular-weight polymers were obtained. A series of polymers derived from DVS were highly crystalline and soluble in hot dimethylacetamide and hot m-cresol, whereas a polymer from DSS was quite amorphous and showed excellent solubility in a wide range of solvents. Polymers IIIa and IIIb had melting temperature below 150°C.     

Sodium hydride-initiated polymerizations of vinyl monomers in aprotic solvents

Polymerizations of several vinyl monomers at 25°C in aprotic solvents (dimethyl sulfoxide, N,N-dimethylacetamide, and hexamethylphosphoric triamide) using sodium hydride dispersion as initiator yield low to intermediate molecular weight polymers. The molecular weight of the resulting polymer as well as the mode of initiation depends on the monomer and aprotic solvent used. Initiation of polymerization of monomers with available α hydrogens (methyl acrylate, acrylonitrile) involves monomer anion, while initiation of a monomer with no α hydrogen (methyl methacrylate) proceeds by a more complex mechanism. In contrast, initiation of styrene and α-methylstyrene proceeds by dimsyl anion addition to monomer in dimethylsulfoxide. Although the triad tacticities and number-average molecular weights of poly(methyl methacrylate) samples obtained from all three aprotic solvents are nearly the same, poly(methyl methacrylates) prepared in dimethyl sulfoxide and N,N-dimethylacetamide give polymers having polydispersities of ～3, while a very polydisperse polymer is obtained in hexamethylphosphoric triamide.     

Synthesis and characterization of phenylated pyrazino-benzimidazophenanthroline polymers

Novel phenylated quinoxaline tetraamines have been prepared and polymerized with 1,4,5,8-naphthalenetetracarboxylic acid in polyphosphoric acid solution. The resulting BBB-type polymers with pendant phenyl groups along the polymer backbone are soluble in m-cresol. The polymers, with inherent viscosities ranging from 0.3 to 0.6 dl/g in sulfuric acid, exhibited thermal stabilities near 500°C under nitrogen and near 400°C in air.     

Preparation and properties of aromatic polypyrazoles from branched bis-β-diketones and aromatic dihydrazines

Aromatic polypyrazoles were prepared by the cyclopolycondensation of branched bis-β-diketones with aromatic dihydrazines. The polymerizations were carried out at 100–150°C in m-cresol or a polar aprotic solvent like dimethyl sulfoxide to produce polymers with inherent viscosities up to 0.98 dl/g. These polypyrazoles were readily soluble in a wide range of solvents that included chloroform and exhibited 10% weight losses between 380 and 425°C in air and 370 and 500°C in nitrogen.     

Synthesis and characterization of some Schiff-base-containing polyimides

The diamine, 4-aminophenyloxy-N-4-[(4-amiophenyloxy)benzylidene]aniline, was prepared via the nucleophilic substitution reaction and was polymerized with different dianhydrides either by one-step solution polymerization reaction or two-step procedure. The latter includes ring-opening polyaddition to give poly(amic acid), followed by cyclodehydration to polyimides. The inherent viscosity ranges from 0.61–0.79 dl/g. Some of the polymers were soluble in most of the organic solvents such as DMSO, DMF, DMAc, NMP, and m-cresol even at room temperature. The degradation temperature of the resultant polymers falls in the ranges from 240–500 °C in nitrogen with only 10% weight loss. Specific heat capacity at 200 °C ranges from 1.0929–2.6275 J g⁻¹ k⁻¹. The temperature at which the maximum degradation of the polymer occurs ranges from 600–630 °C. The glass transition temperature (Tg) values of the polyimides ranged from 185 to 272 °C. The activation energy and enthalpy of the polyimides ranged from 47.5–55.0 kJ/mole and 45.7–53.0 kJ/mole and the moisture absorption in the range of 0.23–0.72%.     

Polyimidines. VI. The comparison of polyimidines from bis(3,3-diphenyl-6-phthalidyl) ketone

New thermally stable polyimidines have been synthesized from bis(3,3-diphenyl-6-phthalidyl) ketone and five diamines: o-phenylenediamine, m-phenylenediamine, 1,5-diaminonapthalene, 1,8-diaminonapthalene, and benzidine. Polymers of low molecular weight (inherent viscosity up to 0.24 dl/g) were obtained by solution and sealed-tube polymerizations. The structural differences of the amines provided information concerning the effects on the thermal stability properties of the resulting polyimidines. The yellow to black polymers exhibited a 10% loss ranging from 420–510°C in air and 460–555°C in nitrogen and were soluble in chloroform and dimethylformamide.     

New poly(amide-imide)s syntheses. VII. Preparation and properties of poly(amide-imide)s derived from 1,5-bis(4-aminophenoxy) naphthalene,trimellitic anhydride,and various aromatic diamines

New bis(phenoxy)naphthalene-containing poly(amide-imide)s having an inherent viscosity in the range of 0.62–1.09 dL/g were prepared by the direct polycondensation of 1,5-bis(4-trimellitimidophenoxy) naphthalene ( I ) and various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in N-methyl-2-pyrrolidone (NMP) in the presence of calcium chloride. The diimide-diacid (I) was prepared by the condensation of 1,5-bis(4-aminophenoxy) naphthalene and trimellitic anhydride. Most of the polymers were soluble in aprotic solvents such as NMP and N,N-dimethylacetamide (DMAc), and afforded transparent, flexible and tough films upon casting from DMAc solutions. Measurements of wide-angle X-ray diffraction revealed that those polymers containing p-phenylene or oxyphenylene groups were characterized as crystalline polymers. Tensile strength and initial moduli of the polymer films ranged from 61–86 MPa and 1.83–2.21 GPa, respectively. Glass transition temperatures of the polymers were in the range of 231–340°C. The melting points of the crystalline polymers ranged from 375–430°C. The 10% weight loss temperatures were above 512°C in nitrogen and 481°C in air. © 1993 John Wiley & Sons, Inc.     

Poly(arylether amides) and poly(aryletherketone amides) via aromatic nucleophilic substitution reactions of self‐polymerizable AB and AB2 monomers

Two new extended self‐polymerizable AB monomers, N‐(4‐fluorobenzoyl)‐4‐amino‐4′‐hydroxydiphenylether and N‐(4‐fluorobenzoyl)‐4‐amino‐4′‐hydroxybiphenyl, were prepared. The monomers were homopolymerized and copolymerized to high‐molecular‐weight, linear poly(arylether amides) in N‐methylpyrrolidone (NMP)/toluene in the presence of potassium carbonate at elevated temperature. The polymers retained NMP up to 200 °C. Samples containing small amounts of the solvent (5–10 wt %) were soluble in polar aprotic solvents. However, after complete removal of the NMP, the polymers were only soluble in strong acids such as sulfuric acid and methanesulfonic acid (MSA). The polymers, which had intrinsic viscosities of 0.57–1.49 dL/g (30.1 ± 0.1 °C in MSA), were semicrystalline with melting temperatures above 400 °C. Two new self‐polymerizable AB₂ amide monomers, N,N′‐bis(4‐fluorobenzoyl)‐3,4‐diamino‐4′‐hydroxydiphenylether and N,N′‐bis(4‐fluorobenzoyl)‐3,5‐diamino‐4′‐hydroxybenzophenone, were also prepared and polymerized to give a hyperbranched poly(arylether amide) and a hyperbranched poly(aryletherketone) amide. The arylfluoride‐terminated, amorphous polymers had intrinsic viscosities of 0.34 and 0.24 dL/g (30.0 ± 0.1 °C in m‐cresol), glass‐transition temperatures of 210–269 °C, and were soluble in a wide variety of organic solvents. Matrix‐assisted laser desorption/ionization time‐of‐flight analysis indicated that the components of the low‐molecular‐weight fractions contained cyclic structures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2374–2389, 2003     

Polyimides derived from bismethylolimides. I. Polyamide–imides from bismethylolimides and dinitriles

New polyamide–imides were synthesized from bismethylolimides and dinitriles. The bismethylolimides, N,N′-bismethylolpyromellitdiimide and N,N′-bismethylolbenzophenonete-tracarboxylic diimide, were prepared by the hydroxymethylation of the corresponding diimides with formaldehyde. The polymerization reaction was carried out in either concentrated sulfuric acid or poly(phosphoric acid), and the former was found to be superior to the latter. The polyamide–imides had inherent viscosities in the 0.08–0.41 dl/g range. Most of these polymers were soluble in m-cresol and dichloroacetic acid. The thermal stability of the polymers was examined by thermogravimetric analysis, and they were found to start to decompose at 275–350°C in air.     

Synthesis and properties of thermally stable polyimides bearing pendent fluorene moieties

A new diamine monomer containing fluorene unit, 3,5‐diamino‐N‐(9H‐fluoren‐2‐yl)benzamide was successfully synthesized via the condensation of 2‐aminofluorene and 3,5‐dinitrobenzoyl chloride and subsequent reduction of the dinitro compound. A series of novel aromatic polyimides having pendent fluorenamide moieties were prepared from the reaction of the diamine monomer and various tetracarboxylic dianhydrides by a conventional two‐step polymerization process. The polyimides were obtained in quantitative yields with inherent viscosities of 0.33–0.44 dl/g. The resulting polymers dissolved in N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide. The glass transition temperature of these polymers was in the range of 261–289°C. They were fairly stable up to a temperature around 450°C and lost 10% weight in the range of 498–556°C in nitrogen. The UV–vis absorption spectra showed that all of the polymers had absorption maxima around 320 nm. Cyclic voltammograms of the polyimides revealed an oxidation wave with a peak around 1.3 V. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis of novel poly(xylylenyl benzimidazole)s

Novel poly(xylylenyl benzimidazole)s (PXBI) with methyl substituents on the xylylene units were synthesized by high-temperature polycondensation techniques. Two different tetraamine hydrochlorides were condensed independently with 2,5-dimethyl-1,4-benzene diacetic acid and 2,4-dimethyl-1,5-benzene diacetic acid in polyphosphoric acid (PPA) to yield different poly(xylylenyl benzimidazole)s. Their syntheses, characterization, and properties such as density, viscosity, solubility, crystallinity, and thermal stability were described. Two model benzimidazoles (MBI) were also synthesized from o-phenylene diamine (OPDA) and the above two diacetic acids to confirm the formation of polymers from the tetraamines. The polymers thus obtained had high intrinsic viscosities in the range of 0.67-0.94 dl/g and were stable up to 450°C.     

New organosoluble and thermally stable poly(amide‐imide)s with benzoxazole or benzothiazole pendent groups: synthesis and characterization

Two new benzoxazole or benzothiazole‐containing diimide‐dicarboxylic acid monomers, such as 2‐[3,5‐bis(N‐trimellitimidoyl)phenyl]benzoxazole ( 2 _o ) or 2‐[3,5‐bis(N‐trimellitimidoyl)phenyl]benzothiazole ( 2 _s ) were synthesized from the condensation reaction between 3,5‐diaminobenzoic acid and 2‐aminophenol or 2‐aminothiophenol in polyphosphoric acid (PPA) with subsequent reaction of trimellitic anhydride in the presence of glacial acetic acid, respectively, and two new series of modified aromatic poly(amide‐imide)s were prepared. This preparation was done with pendent benzoxazole or benzothiazole units from the newly synthesized diimide‐dicarboxylic acid and various aromatic diamines by triphenyl phosphite‐activated polycondensation. In addition, the corresponding unsubstituted poly(amide‐imide)s were prepared under identical experimental conditions for comparative purposes. Characterization of polymers was accomplished by inherent viscosity measurements, FT‐IR, UV–visible, ¹H‐NMR spectroscopy and thermogravimetry. The polymers were obtained in quantitative yields with inherent viscosities between 0.39 and 0.81 dl g^?1. The solubilities of modified poly(amide‐imide)s in common organic solvents as well as their thermal stability were enhanced compared to those of the corresponding unmodified poly(amide‐imide)s. The glass transition temperature, 10% weight loss temperature, and char yields at 800°C were, respectively, 7–26°C, 17–46°C and 2–5% higher than those of the unmodified polymers. Copyright © 2010 John Wiley & Sons, Ltd.     

Functional polymers. IX. Polycarbonates and alternating copolycarbonates of bithionol

A number of polycarbonates, alternating copolycarbonates, polyurethanes, and terpolymers with carbonate and/or urethane linkages utilizing bithionol [2,2'-thiobis(4,6-dichlorophenol)] as the bisphenol component of the polymers have been synthesized. Bithionol has been demonstrated to give a polycarbonate with an inherent viscosity of about 0.5 dl/g. The polycarbonate is amorphous and has a glass transition temperature T_g of about 105°C. Alternating copolycarbonates and polyurethanes involving bithionol are most conveniently prepared from the bischloroformate of bithionol. An alternating copolycarbonate of bithionol and poly(ethylene glycol) of molecular weight 4000 has an inherent viscosity of more than 1.2 dl/g, is water soluble, and has characteristics similar to those of low-density polyethylene. Alternating copolymers of bithionol and other hindered bisphenols have been synthesized and can be visualized as having an antibacterial agent and an antioxidant in the same polymer chain. These polymers have the potential to act as very useful materials for the controlled release of drugs while only forming carbon dioxide as the additional small molecule fragment on hydrolysis.     

Synthesis of new ordered aromatic polyester copolymers

Aromatic polyesters of 3,5-di-tert-butyl-4-hydroxybenzoic acid and 3,5-diisopropyl-4-hydroxybenzoic acid were prepared. The polymers were found to be high-melting but largely insoluble in organic solvents. The polymer based on 3,5-di-tert-butyl-4-hydroxy-benzoic acid was not degraded to monomer by sulfuric acid. A number of new aromatic polyesters were also prepared. Several new monomers for aromatic polyesters were synthesized, including bis(2,5-di-tert-butyl-4-carbophenoxyphenyl)terephthalate, m- and p-phenylene bis(3,5-di-tert-butyl-4-hydroxybenzoate), bis(2,6-di-tert-butyl-4-chlorocarboxyphenyl)terephthalate, and m-phenylene bis(3,5-diisopropyl-4-hydroxybenzoate). An aromatic polyester prepared from bis(2,6-di-tert-butyl-4-chlorocarboxyphenyl) terephthalate and resorcinol had a η_inh (trichloroethylene) of 1.05 (0.5%, 30°C) and a possible melting point of 330°C (DSC). Tough, creasable films could be cast from trichloroethylene solution of this polymer. Attempts to observe or to trap the keto-ketene that might result when 3,5-di-tert-butyl-4-hydroxybenzoyl chloride is treated with base were unsuccessful.     

Liquid crystal polymers. 14. Synthesis and properties of thermotropic poly(1,4-alkylphenylene terephthalates)

A series of terephthalate polyesters was prepared from substituted hydroquinone monomers that contained a single cyclic or branched alkyl group. All the polymers were crystalline with melting points well below 400°C that decreased as the size of the cycloalkyl substituent increased. Most of the polymers had clearing temperatures below 400°C and all formed nematic melts. Copolyesters that contained equimolar amounts of two different substituted hydroquinone monomers, which were crystalline and had broad temperature ranges for nematic phase formation, were also prepared.     

Poly(enamine-ketones) from hydrogen-terminated aromatic dipropynones and aromatic diamines

Poly(enamine-ketones) were prepared by the nucleophilic (Michael-type) addition of various aromatic diamines to 1,1′-(1,3- or 1,4-phenylene)bis(2-propyn-1-one)(1,3 or 1,4-PPO) in m-cresol at 5–23°C. The low molecular weight polymers (inherent viscosity of 0.25 dL/g) exhibited limited solubility in organic solvents. Glass transition temperatures were generally undetectable by differential scanning calorimetry while polymer decomposition temperatures (10% weight loss), as measured by thermogravimetric analysis, were observed from 355 to 419°C. Polymers prepared from 1,4-PPO were semi-crystalline as shown by wide-angle X-ray diffraction. The poly(enamine-ketone) structure was confirmed by matching infrared spectral characteristics of the polymers with those of well-characterized model enamine ketones.