Heat capacities and entropies of liquid,high-melting-point polymers containing phenylene groups (PEEK,PC, and PET)

The heat capacity at constant pressure of liquid PEEK, poly(oxy-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene), has been measured by scanning calorimetry from 420 to 680 K, and that of PC, poly(4,4′-isopropylidenediphenylene carbonate), from 325 to 610 K. These new data were combined with data-bank data for PC and PET, poly(ethylene terephthalate), over wide temperature ranges. An addition scheme for liquid heat capacities of similar macromolecules has been obtained. In addition, values of absolute entropy, residual entropy for the glassy state, enthalpy, and Gibbs function are estimated for these three polymers. Both melting and glass transition temperatures have been confirmed. The heat capacity increases at the glass transition temperature have been determined by making use of previously calculated solid-state heat capacities.     

Synthesis and Properties of Aromatic Poly(Ether Sulfone)s and Poly(Etherketone)s Containing Naphthalene or Quinoline Units,and Methyl-Substituted Biphenyl-4,4′-Diols

Abstract

A series of poly(ether sulfone)s and poly(ether ketone)s were synthesized from combinations of 1,5- and 2,6-bis(4-fluorosulfonyl)naphthalene, 2,6-bis(4-fluorobenzoyl)naphthalene, and 2,6-bis(4-fluorobenzoyl)quinoline with 3,3′,5,5′-tetramethylbiphenyl-4,4′-diol and 2,2′,3,3′,5,5′-hexamethylbiphenyl-4,4′-diol. The polycondensations proceeded quantitatively in diphenylsulfone in the presence of anhydrous potassium carbonate to afford polymers with inherent viscosities between 0.40 and 1.28 dL/g measured in N-methyl-2-pyrrolidone or concentrated sulfuric acid. The tetramethyl- and hexamethyl-substituted aromatic polyethers exhibited good thermal stability, did not decompose below 330°C in both air and nitrogen atmospheres, and had higher glass transition temperatures than the corresponding unsubstituted polymers. The methylsubstituted poly(ether sulfone)s and poly(ether ketone)s showed good solubility in such common organic solvents as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, tetrahydrofuran, chloroform, and 1,4-dioxane.     

Synthesis of polyphenylene ether and thioether ketones

The known polymerization of 4,4′-difluorobenzophenone (DFB) with the dianion of hydroquinone to poly(phenylene ether ether ketone) (PEEK) and polymerization of either DFB with the dianion of 4,4′-dihydroxybenzophenone or self polycondensation of the anion of 4-hydroxy-4′-fluoro-benzophenone to poly(phenylene ether ketone) (PEK) were studied in N-cyclohexyl-2-pyrrolidone (CHP), which is a high-boiling aprotic polar solvent. The formation of high-molecular weight PEEK and PEK in this solvent was very efficient. The reactivity in CHP can be ascribed to effective solvation of metal ions rendering the anion very reactive toward nucleophilic substitution. The polymerization was extended to 4,4′-bis(4-fluorobenzoyl)diphenyl ether and 1,4-bis[4-(4-fluorobenzoyl)phenoxy]benzene to give a high molecular weight polymer with PEK and PEEK repeating units and PEEK respectively. The polymerization of DFB with purified anhydrous sodium sulfide in CHP gave rapidly a high molecular weight poly(phenylene ketone sulfide) (PKS). In contrast, diphenyl sulfone (DPS) was not very effective in obtaining such a high molecular weight PKS even with prolonged heating, which suggests the uniqueness of CHP in promoting a high degree of polymerization.     

Preparation and characterization of aromatic copolyesters containing the o,o′-biphenylene ring system

Poly[oxy-2,2′-diphenyleneoxyisophthaloyl-b-oxy(2-methyl-1,3-phenylene)oxyterephthaloyl] I, poly[oxy-2,2′-diphenyleneoxyterephthaloyl-b-oxy(2-methyl-1,3-phenylene)oxyterephthaloyl] II, poly(oxy-2,2′-diphenyleneoxyisophthaloyl-b-oxy-2,2′-diphenyleneoxyterephthaloyl) III, poly[oxy-2,2′-diphenyleneoxyterephthaloyl-b-oxy(2-methyl-1,4-phenylene)oxyterephthaloyl] IV, poly[oxy2,2′-diphenyleneoxyterephthaloyl-b-oxy(2-chloro-1,4-phenylene)oxyterephthaloyl] V, poly[oxy-2,2′-diphenyleneoxyterephthaloyl-co-oxy(2-chloro-1,4-phenylene)oxyterephthaloyl] VI, and poly[oxy-2,2′-diphenyleneoxyterephthaloyl-co-oxy(2-methyl-1,4-phenylene)oxyterephthaloyl] VII have been synthesized and characterized. Random copolyester VI appears to form a birefringent fluid phase above the melting temperature.     

Studies on the thermotropic liquid crystalline polycarbonates. II. Synthesis and properties of fully aromatic liquid crystalline polycarbonates

Four series of fully aromatic polycarbonates were prepared by using melt polycondensation from various novel phenylene diphenyl dicarbonates: 1,4-phenylenc diphenyl dicarbonate, 1,3-phenylene diphenyl dicarbonate, methyl-1,4-phenylene diphenyl dicarbonate, and chloro-1,4-phenylene diphenyl dicarbonate with various diols—4,4′-biphenyl diol, hydroquinone, 2,7-naphthalene diol and 1,5-naphthalene diol, respectively. The thermotropic liquid crystalline properties of synthesized polycarbonates were investigated by: (1) examination of the melt birefringence and stir opalescence by a polarizing microscope equipped with a heating stage, (2) characterization by a differential scanning calorimeter (DSC), and (3) analysis of the wide angle x-ray diffraction. It was found that the 1,3-phenylene unit is compensated for the nonlinearity of the carbonate group, and polycarbonates which contain this bent shape unit showed excellent wide mesophase transition in this study. © 1993 John Wiley & Sons, Inc.     

一种聚芳醚酮齐聚物的合成和晶体结构(英文)

合成了一种聚芳醚酮齐聚物 4 ,4′-双 (对氟苯甲酰基 )二苯醚 ,并以IR ,DSC ,13CNMR等技术对其进行了表征。运用多晶粉末X射线衍射方法 ,对其晶体结构进行了确定 ,其晶体结构为首次报道。     

Thermal degradation of a polyphenylimide-quinoxaline in air and under vacuum

Three samples of poly{2,2′-[N,N′-bis(1,4-phenylene)benzophenone-3,3′,4,4′-tetracarboxylimide-6,6′-bis(3-phenyl-quinoxaline)]} (PPIQ), were prepared, differing in molecular weights and polymer chain endings. Their thermal degradation in vacuo and in air was determined by isothermal weight loss measurements. As in the case of poly-[2,2′-(1,4-phenylene)-6,6′-bis(3-phenylquinoxaline)] (PPQ), the temperature coefficients of thermal degradation in air were independent of molecular weight. However, in contrast, the temperature coefficients were independent of the type of polymer endgroups. It is, therefore, concluded that, contrary to amino-terminated PPQ's, polymer chain-end unzipping of PPIQ is of minor importance during thermal-oxidative degradation.     

Desulfurization and ortho-metalation reactions of dimanganese decacarbonyl

Thiobenzophenone, and 4,4′-disubstituted derivatives having moderately electron-donating (methyl, methoxy) or electron-withdrawing (fluoro) groups, react with dimanganese decacarbonyl in refluxing heptane to produce olefins (and a sulfur manganese carbonyl complex) in good yield. 4,4′-Bis(dialkylamino)thiobenzophenones reacted with the metal carbonyl to give sulfur-donor ligand ortho-metalated complexes as the major product and 4,4′-bis(dialkylamino)diphenylmethanes as by-products. A mechanistic scheme is proposed for these reactions.     

Polyaromatic pyrazines: Synthesis and thermogravimetric analysis

The syntheses of five polyaromatic pyrazine polymers are described. These polymers were synthesized by the condensation of bis-α-haloaromatic ketones with ammonia in N,N-dimethylacetamide (DMAc) solvent in the presence of air or peroxides. The condensation of bis-p-(α-bromoacetyl)benzene (IIIa), bis-p,p′-(α-chloroacetyl)biphenyl (IIIb) bis-p,p′-(α-chloroacetyl)diphenyl ether (IIIc), bis-p,p′-(α-chloroacetyl)diphenylmethane (IIId), and α,α′-dibenzoyl-α,α′-dibromo-p-xylene (V) under these reaction conditions gave poly[2,5-(1,4-phenylene)pyrazine] (IVa), poly[2,5-(4,4′-biphenylene)-pyrazine] (IVb), poly[2,5-(4,4′-oxydiphenylene)pyrazine] (IVc), poly[2,5-(4,4′-methylenediphenylene)pyrazine] (IVd), and poly[2,5-(1,4-phenylene)-3,6-diphenylpyrazine] (VI), respectively. Thermogravimetric analysis (TGA) of these polymers showed them to be thermally stable up to the temperature range of 450–550°C in air for short periods of time. The inherent viscosities of these polymers ranged from 0.18 to 1.30.     

Synthesis,characterization, and blends of high temperature poly(arylether sulfone)s

The preparation of poly(4-oxy-1,4-phenylenesulfonyl-4,4′-biphenylene-4-sulfonylphenylene) (PBP) has been accomplished by the base mediated, polycondensation reaction between two biphenyl containing monomers. The bisphenol, 4,4′-bis[(4-hydroxyphenyl) sulfonyl]biphenyl (HSB), was reacted with 4,4′-bis[(4-chlorophenyl)sulfonyl]-biphenyl (CSB) in tetramethylene sulfone solvent. The highest mechanical properties and glass transition temperature was observed for polymer PBP with a reduced viscosity around 1.0 dL/g. Consequently, the current synthesis route provides polymer with higher properties than other historical preparative routes. Blends of PBP with a different poly(ether sulfone) were miscible based on the observance of a single glass transition temperature. The T_gs of the polymer blends exhibited an unusual positive deviation from the weighted linear averages of the components.     

Nucleophilic substitution reactions of 1,4-dichlorobenzene chromium tricarbonyl with mono- and diphenoxides

The nucleophilic substitution reactions of 1,4-dichlorobenzene chromium tricarbonyl ( 1 ) with the phenoxide anion were investigated. The substitution of the first chlorine was very fast and gave the mono-substituted product in high yield. The substitution of the second chlorine group was significantly retarded by the presence of the phenoxy group incorporated during the first reaction and also due to the competing decomplexation reaction. The application of 1,4-dichlorobenzene chromium tricarbonyl ( 1 ) to the synthesis of new monomers was demonstrated by the preparation of 2,2′-bis[4-(4-chlorophenoxy)phenyl]propane ( 9 ). 2,2′-Bis[4-(4-chlorophenoxyl)phenyl]propane ( 9 ) was synthesized by a nucleophilic substitution reaction of 4,4′-isopropylidenediphenolate with 1,4-dichlorobenzene chromium tricarbonyl ( 1 ) followed by decomplexation with I₂. 2,2′-Bis[4-(4-chlorophenoxy)-phenyl]propane ( 9 ) was also synthesized via a three-step reaction starting from the nucleophilic substitution reaction of 4,4′-isopropylidenediphenol ( 7a ) with 1-chloro-4-nitrobenzene ( 10 ). 2,2′-Bis[4-(4-chlorophenoxy)phenyl]propane ( 9 ) was polymerized by a Ni(0)-catalyzed reaction to yield amorphous aromatic polyethers with number-average molecular weights of up to 11,200 g/mol. © 1993 John Wiley & Sons, Inc.     

Kondesationen mit hydrazin-N,N′-dicarbonsäurediamidin,XXIII [1] fluorierte β-diketone als reaktionspartner

Application of a 30% aqueous potassium carbonate solution for the condensation of 1,2-hydrazinedicaboxamidine with 1,1,1-trifluoro-2,4-pentanedione leads to the formation of 4,4′-dimethyl-6,6′-bis(trifluoromethyl)-2,2′-hydrazopyrimidine, with 1,1,1-trifluoro-2,4-hexanedione to 4,4′-diethyl-6,6′-bis-(trifluoromethyl)-2,2′-hydrazopyrimidine. 2-Guanidinoamino-4-methyl-6-trifluoromethylpyridine formed as an intermediate in this reacton may be isolated, while 4-ethyl-2-guanidinoamino-6-trifluoromethylpyrimidine undergoes cyclization to yield 2-amino-5-ethyl-7-trifluoromethyl-s-triazolo[1,5-a]pyrimidine.     

Thermotropic copolyesters containing the 1,4-cyclohexylenedimethylene spacer

Poly[oxy(2-methyl-1,4-phenylene)oxyterephthaloyl-co-oxy(2-methyl-1,4-phenylene)oxy-1,4-cyclohexanediacetoyl] (I), poly[oxy(2-chloro-1,4-phenylene)oxyterephthaloyl-co-oxymethylene-1,4-cyclohexylenemethyleneoxyterephthaloyl] ( II ), and poly[oxy(2-methyl-1,4-phenylene)oxyterephthaloyl-co-oxymethylene-1,4-cyclohexylenemethyleneoxyterephthaloyl] ( III ) were synthesized and shown to form birefringent fluid states in the melt.     

Synthesis of perhydro-1,2,5,6-tetrazocine and derivatives

Synthetic routes to the title compounds were explored. 1,2,5,6-Tetraacetylperhydro-1,2,5,6-tetrazocine ( 6 , 36%) was produced from ethylene glycol bis-p-toluenesulfonate and the potassium salt of 1,2-bis(N,N′ -diacetylhydrazino)ethane in refluxing mesitylene. Its acid-catalyzed hydrolysis led to perhydro-1,2,5,6-tetrazocine ( 9 ), an air-sensitive, crystalline solid, the first reported unsubstituted tetraazacyclooctane and the first example of an unsubstituted macrocycle incorporating two or more endocyclic hydrazino groups. 1,2-Bis(hydrazino)ethane ( 4 ) and diisobutyl oxalate in refluxing dimethylformamide gave 1,4-diamino-2,3-diketopiperazine ( 11 ) rather than 3,4-diketoperhydro-1,2,5,6-tetrazoeine ( 12 ). The acid-catalyzed reaction of benzil with 4 gave 3,4,7,8-tetraaza-1,2,9,10-tetraphenyl-2,8-dccadien-1,10-dione ( 20 ).     

Molecular characteristics and solution behavior of prepolymers of several polyimides: Effect of synthesis conditions

With the use of light scattering and viscometry, as well as the employment of various aprotic solvents for the polymer synthesis, the molecular characteristics of two poly(amic acids), namely, poly[4,4′-bis(4″-N-phenoxy)diphenylsulfone]amic acid of 1,3-bis(3′,4-dicarboxyphenoxy)benzene and poly[4,4′-bis(4″-N-phenoxy)diphenyl]amic acid of 1,3-bis(3′,4-dicarboxyphenoxy)benzene, have been studied at various molar ratios of the starting reagents and concentrations of the polycondensation solution. The molecular masses of poly(amic acids) depend on the thermodynamic quality of a solvent which may be changed by varying the nature of the solvent, the structure of the resulting polymer, or the chemical nature of the mixture.     

Preparation of silicon containing polymers. II.. Effect of structure on the thermal stability of organosilicon aramids

Two silicon-containing acid dichlorides, bis(4-chlorocarbonylphenyl)dimethylsilane and bis(4-chlorocarbonylphenyl)diphenylsilane, were synthesized and reacted with 1,3-phenylene diamine, 1,4-phenylene diamine, 4,4′-diaminodiphenyl, 4,4′-diaminodiphenyl methane 4,4′-diaminodiphenyl ether, and 4,4′-diaminodiphenyl sulfone in the preparation of 12 structurally different high molecular weight aromatic polyamides. A low-temperature interfacial polycondensation technique was used. Most of the polyamides formed tough, transparent, flexible films and were characterized by solubility, solution viscosity, infrared spectroscopy (IR), and glass transition temperature (T_g). The thermal behavior of these aramids was studied by dynamic thermogravimetry. The effect of diamine and acid dichloride structure on the aramids properties is also discussed.     

Poly(Aryl Ether)s from a Novel Biphenol Monomer Containing a Dicyanoarylene Group

Abstract

The preparation of a novel biphenol, 1,4-bis(4-hydroxyphenyl)-2,3-dicyanonaphthalene, from phenolphthalein is described. This biphenol was prepared in high yield in a four-step reaction sequence. The biphenol can be polymerized with activated dihalides such as 1,2-bis-(4-fluorobenzoyl)-3,4,5,6-tetraphenylbenzene, bis(4-fluorophenyl) sulfone, and 4,4′-dichlorobenzophenone to give high molecular weight amorphous poly(aryl ether)s. The polymers have glass transition temperatures ranging from 284 to 319°C and are easily cast into flexible, colorless, and transparent films. The 5% weight loss temperatures of these polymers, by thermogravimetric analysis in air and nitrogen, are all above 500°C.     

Synthesis of polymer intermediates containing the hexafluoroisopropylidene group via functionalization of 2,2-diphenylhexafluoropropane

The title compound was synthesized by hydrogenolysis of its precursor 2,2-bis(4-trifluoromethanesulfonatophenyl)hexafluoropropane ( 2 ) in the presence of a base. 2,2-Diphenylhexafluoropropane ( 6 ) can be appropriately functionalized at the 3,3′-positions to give the diamino ( 7 ), dibromo ( 11 ), dicarboxaldehydo ( 13 ), 3-ethynyl-3′-carboxaldehydo ( 14 ) derivatives which are important monomers in the synthesis of various high-temperatures resistant polymers and oligomers containing the hexafluoroisopropylidene (6F) group. 2,2-Bis(4-triflatophenyl)hexafluoropropane ( 2 ) undergoes quantitative dinitration at the 3,3′-positions to yield 2,2-bis(3-nitro-4-triflatophenyl)hexafluoropropane ( 3 ) which ultimately leads to the 3,3′-diamino-4,4′-bis(arylamino) ( 5 ) and 3,3′-diamino-4,4′-dihydroxy ( 8 ) derivatives which are specifically designed for phenylbenzimidazole, benzimidazoquinazoline, and benzoxazole polymers and oligomers.     

TTF单元与苯单元构建的新型TTF环蕃的合成和性质

以4,5-二(2'-氰乙基硫基)-1,3-二硫杂环戊烯-2-硫酮为原料经甲醇钠消除一个氰乙基生成4-(2'-氰乙基硫基)-1,3-二硫杂环戊烯-2-硫酮的单钠盐, 生成的单钠盐再与1,4-二(氯甲基)苯反应生成4,4'-二(2-氰乙基硫基)-5,5'-(1,4-二亚甲基苯)-二(1,3-二硫杂环戊烯-2-硫酮). 接着在乙酸汞的作用下生成4,4'-二(2-氰乙基硫基)-5,5'-(1,4-二亚甲基苯)-二(1,3-二硫杂环戊烯-2-酮), 此化合物在亚磷酸三乙酯的作用下发生偶联反应, 生成由TTF单元和苯单元构建的新型四硫富瓦烯环蕃和另一种四硫富瓦烯衍生物. 并分别通过循环伏安法和化学氧化法对它们及其导电复合物的电化学性质和紫外光谱进行了研究. 还研究了这种新型四硫富瓦烯环蕃在金纳米颗粒表面自组装行为.     

Synthesis and Characterization of Poly(Aryl Ether-Bissulfone)s

A series of poly(aryl ether-bissulfone)s were synthesized from bis-phenols, 4,4′-bis(4-chlorophenylsulfonyl)biphenyl, and 4,4′-bis(4-fluorophenylsulfonyl)biphenyl. The bishalide monomers were synthesized by reaction of 4,4′-bis(chlorosulfonyl)biphenyl with a suitable aryl halide. Potassium carbonate mediated reaction in di-methylacetamide gave high molecular weight polymers in excellent yield. The polymers are soluble in dipolar aprotic solvents. Unlike the corresponding monosulfone analogues, the poly(aryl ether-bissulfone)s exhibited poor solubility in chlorinated hydrocarbons. The glass transition temperatures of the polymers are among the highest known for poly(aryl ether)s (241-271 °C). In addition, the polymers exhibit excellent thermal stability and they produce clear, colorless tough films by solution casting or compression molding.