New high temperature polymers. I. Wholly aromatic ordered copolyamides

Wholly aromatic ordered copolyamides of unusually high thermal stability were prepared by the condensation of aromatic diacid chlorides with symmetrical diamines containing preformed aromatic amide units in an ordered arrangement. The preservation of order in the condensation step was assured by using interfacial or solution polymerization techniques at temperatures below 50°C. Each polymer contains units derived from aminobenzoic acids, arylene diamines, and arylene diacids. By use of para- and meta- phenylene units, eight different polymers are possible; all were prepared. Differential thermal analyses and thermogravimetric analyses showed these polymers to have melting points or decomposition temperatures in a range from 410°C. for the all-meta polymer to 555°C. for the all-para one. Substitution of the internal N-hydrogens of the diamines with methyl groups or phenyl groups leads to additional ordered copolymers. Several were prepared, but their melting points were much lower than those of the parent polymers limiting their usefulness in high temperature applications. Tough pliable films were prepared from all eight unsubstituted polymers, and crystalline fibers with tenacities of ca. 6 g./den. were prepared from three of the polymers. The properties of the fibers were retained to a high degree even when determined at temperatures up to 400°C. Fibers aged at 300°C. for extended periods of time showed remarkable retention of fiber properties.     

High-Modulus Wholly Aromatic Fibers. I. Wholly Ordered Polyamide-Hydrazides and Poly-1,3,4-oxadiazole—Amides

Several completely ordered polyamide-hydrazide copolymers were prepared via low temperature poly condensation of aromatic diacid chlorides with symmetrical aromatic diamines containing preformed dihydrazide linkages. Highly crystalline, hot-drawn fibers of the polyamide-hydrazide containing only para-oriented phenylene units showed unusually high strength and exceptionally high initial modulus: 10.8 and 508 g/den, respectively, at 2.9% elongation-to-break. The as-spun fibers also exhibited rather high tensile strength and unusually high initial modulus: 8.2 and 291 g/den, respectively, at 9.4% elongation-to-break. The hot-drawn fiber retained considerable strength at elevated temperatures, exhibiting a tenacity of 1.4 g/den and an initial modulus of 169 g/den at 350°C. Heat-aging of the as-spun fiber at 185°C in air showed that 66% of the original tenacity, 41% of the elongation, and 86% of the modulus were retained even after 336 hr. Substitution of as little as 25 mole % meta-oriented phenylene rings for para-oriented ones resulted in loss of the ultra-high strength and modulus, giving tensile properties comparable to those of fibers from wholly aromatic polyamides of the meta-oriented type. Fibers from the polyamide-hydrazides containing 50 mole % meta-oriented rings showed similar properties. Although ordered oxadiazole-amide copolymers were obtained from diamines containing two preformed oxadiazole linkages separated by m-phenylene rings, fibers could not be spun from them. Fiber of an ordered oxadiazole-amide copolymer was obtained, however, by heat treatment of the wholly p-phenylene ordered poly amide-hydrazide copolymer precursor fiber. Such a fiber exhibited a tenacity of 15.3 g/den, 3.6% elongation-to-break, and 564 g/den initial modulus.     

Synthesis and characterization of aromatic polyamides from 1,1-bis(4-aminophenyl)-2,2-diphenylethylene and aromatic diacid chlorides

Novel, soluble aromatic polyamides and copolyamides containing tetraphenylethylene units were prepared by the low temperature solution polycondensation of 1,1-bis(4-aminophenyl)-2,2-diphenylethylene and aromatic diamines with various aromatic diacid chlorides. Highmolecular-weight polyamides having inherent viscosities of 0.6–1.5 dL/g and number-average molecular weight above 21000 were obtained quantitatively. These polymers were readily soluble in various solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide (DMAc), and dimethyl sulfoxide and gave pale yellow, transparent, flexible films by casting from DMAc solution. The polymers had glass transition temperatures between 290 and 340°C, and started to lose weight around 400°C, with 10% weight loss being recorded at about 470°C in air.     

Synthesis and characterization of soluble polyamides based on 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane and 2,2-bis[4-(4-aminophenoxy)phenyl]propane and diacid chlorides

Aromatic soluble polyamides and copolyamides having hexafluoroisopropylidene and isopropylidene moieties in the molecular structure of polymer chain were prepared by reacting the aromatic diacid chlorides and fluorine or nonfluorine containing aromatic diamines using low-temperature polycondensation process. Polymers were produced with high yield and moderate to high inherent viscosity. All polyimides and copolyamides showed thermal stability above 440°C and glass transition temperature above 200°C. Some of the polyamides were cast into transparent bulk films which were further characterized by mechanical, x-ray, and water absorption analysis. Fluoro polyamides showed superior structural properties as compared to nonfluoro polyamides. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of random poly(amide-sulfonamide)s. II. Polymers from unsymmetrical diamine monomers

Novel poly(amide-sulfonamide)s have been prepared by reacting terephthalic, isophthalic, and sebacic acid and their acid chlorides with variously substituted diamines containing preformed sulfonamide linkages utilizing solution polymerization techniques. Inherent viscosities of the prepared polymers varied from 0.22 to 1.21 dL/g. Those having inherent viscosities greater than 0.4 dL/g formed clear, tough, flexible films. Glass transition temperatures ranged from 87 to 273°C. Thermogravimetric analyses of the polymers showed moderate thermal stability.     

Thermal properties and solubility of ordered aromatic polyamides containing a methyl-substituted phenylene linkage

Ordered aromatic polyamides and copolyamides were prepared by the polycondensation of terephthaloyl and isophthaloyl dichlorides with symmetrical diamines containing preformed amide linkages derived from unsymmetrical methyl—substituted aromatic diamines at low temperature. Thermal properties and solubilities of the ordered polyamides were compared with those of the corresponding random polyamides. There was little difference between thermal stabilities of the ordered polyamide and the corresponding random one, while the former was less soluble in organic solvents than the latter, depending on the extent of hydrogen bonding of the amide groups. The thermal stability of the alternating copolyamides containing both terephthaloyl and isophthaloyl groups as acid components was less than that of the corresponding homopolymers having either a terephthaloyl or an isophthaloyl group, and the solubility of the former resembled that of the corresponding ordered homopolysiophthalamides in accord with the extent of hydrogen bonding of the amide groups in both polymers.     

Preparation and properties of polyamides containing p-terphenyl units

Novel polyamides that contained p-terphenyl units were prepared with inherent viscosities in the range of 0.4–1.7 dL/g by the polycondensation of 4,4″-dichloroformyl-p-terphenyl with aromatic diamines and 4,4″-diamino-p-terphenyl with aromatic dicarbonyl chlorides. Polyamides composed of only paraoriented phenylene units were insoluble in all solvents and showed a high degree of crystallinity. A series of polyamides that contained p-terphenyl units were more thermostable than corresponding polymers with p-phenylene or biphenylene linkages.     

High-Modulus Wholly Aromatic Fibers. II. Partially Ordered Polyamide-Hydrazides

Partially ordered polyarnide-hydrazides were produced by the poly condensation of diacid chlorides with aminobenz-hydrazides, the order that results being a consequence of the considerably more rapid reaction of a diacid chloride with the hydrazide group in competition with the aromatic amine group of the aminobenzhydrazide. Fibers were produced from a series of such polymers containing from 50 mole % meta-oriented phenylene rings to 100 mole % para-oriented ones. Fiber from the wholly para-oriented type of polymer exhibited very high strength and modulus: 12.5 and 468 g/den, respectively, at 4.3% elongation-to-break. Although the crystallinity and density observed for hot-drawn fibers of partially ordered completely para-oriented polyarnide-hydrazides were comparable to the crystallinity and density of fibers of the isomeric wholly ordered polymer, the partially ordered polymers were more readily spun to the ultra-high strength and high modulus type fibers, probably because their greater solubility made them easier to spin.     

Poly(1,3,4-oxadiazole-amide)s containing pendent imide groups

A series of new poly(1,3,4-oxadiazole-amide)s containing pendent imide groups has been synthesized by solution polycondensation of aromatic diamines containing preformed 1,3,4-oxadiazole rings with two diacid chlorides containing imide rings. These polymers were also prepared by the reaction of the same diacid chlorides with p-aminobenzhydrazide which were subsequently cyclodehydrated in solid state. The polymers were soluble in polar amidic solvents and some of them gave transparent flexible films by casting from solutions. They showed high thermal stability with decomposition temperatures above 400°C and glass transition temperatures in the range of 245–327°C. They had low dielectric constants, in the range of 3.32–3.94, and good tensile properties.     

Preparation and properties of fluorine-containing aromatic polyamides from tetrafluorophthaloyl chlorides and aromatic diamines

New fluorine-containing aromatic polyamides with inherent viscosities of 0.4–1.8 dL/g were prepared by the low temperature solution polycondensation of tetrafluoroisophthaloyl and tetrafluoroterephthaloyl chlorides with N,N′-bis(trimethylsilyl)-substituted aromatic diamines. The aromatic polyperfluoroisophthalamides were amorphous polymers with glass transition temperatures around 280°C, whereas the polyperfluoroterephthalamides were crystalline. Most of these aromatic polyamides were soluble in organic solvents, and began to decompose around 330°C in air or nitrogen atmosphere.     

Synthesis and characterization of novel aromatic polyamides from 3,4-bis(4-aminophenyl)-2,5-diphenylpyrrole and aromatic diacid chlorides

A new polymer-forming monomer, 3,4-bis(4-aminophenyl)-2,5-diphenylpyrrole, was synthesized in three steps starting from 4′-nitrodeoxybenzoin. Tetraphenylpyrrole-containing aromatic polyamides and copolyamides were prepared from the diamine with various aromatic diacid chlorides and from a mixture of the diamine and 4,4′-oxydianiline with terephthaloyl chloride, respectively. The resultant polymers had inherent viscosities in the 0.3–1.8 dL/g range and were generally soluble in various organic solvents including N,N-dimethylacetamide and m-cresol. They have glass transition temperatures in the range of 306–333°C and showed no weight loss below 380°C in both air and nitrogen atmospheres.     

Synthesis and properties of polysulfonamides containing thiophene links

In order to study the synthesis and properties of polysulfonamides containing thiophene links, 2,2-bis(5-chlorosulfonyl-2-thienyl)propane [BCTP], 2,2-bis(5-chlorosulfonyl-2-thienyl)butane [BCTB], 1,1-bis(5-chlorosulfonyl-2-thienyl)cyclohexane [BCTC], and 2,4-dichlorosulfonyl thiophene [DCST] were prepared and interfacial polycondensations with various aliphatic diamines were carried out. The resulting polymers had inherent viscosities in the range of 0.13–0.41 dL/g and showed high extent of moisture absorptions. Most of the polysulfonamides were soluble in electron-donating solvents such as pyridine, DMF, DMSO, NMP, etc. These polysulfonamides exhibited relatively good thermal stabilities. The TGA data revealed 5% weight losses at 275–405°C and residual weights at 500°C were 13–40% under nitrogen. It was also found that dithienyldisulfonyl chlorides produced more thermally stable polymers than DCST, which were comparable to common polysulfonamides from aromatic disulfonyl chlorides.     

Aromatic polyisophthalamides with oxybenzoyl pendent groups

A series of polyisophthalamides containing pendent oxybenzoyl groups were prepared from 5-oxybenzoyl-isophthaloyl chloride and aromatic diamines. The analogous unsubstituted polyisophthalamides were also prepared in order to compare the two series and to determine the effect of oxybenzoyl pendent groups on the properties of aromatic polyamides. The modified polymers exhibited better solubility than, and approximately the same glass transition temperatures (in the range 260–290°C) as, the parent unsubstituted polymers. The mechanical strength of polymer films was affected only to a small extent by the presence of side groups, but the thermal resistance was negatively affected, with the result that polyisophthalamides with oxybenzoyl pendent groups began to decompose at about 360°C (TGA), 60–100°C lower than the unsubstituted polyisophthalamides. By means of an appropriate thermal treatment, crosslinking of the modified polymers was achieved and their thermal resistance significantly enhanced.     

Regular Copolyamides. IX. Some Aliphatic Aromatic Copolyoxamides

Abstract

Aromatic/aliphatic regular copolyoxamides were prepared from aromatic diamine-oxamides and aliphatic diacid chlorides of various lengths of methylene groups by solution polymerization. The aromatic diamine oxamides, N,N′-bis(4-aminophenyl)oxamide and N,N′-bis(3-aminophenyl)oxamide were prepared and both were reacted with adipoyl chloride, suberoyl chloride, and sebacoyl chloride to form six new regular copolyoxamides. The polymers formed were soluble in sulfuric acid and also in some polar amide solvents. All copolyoxamides were high melting, with the meta-phenylene copolyoxamides melting from 346 to 373°C with decreasing length of the aliphatic diacid chloride, and the para-phenylene copolyoxamides decomposing prior to melting at near 400°C. The new polymers were characterized by UV spectrophotometry, differential scanning calorimetry, and thermal gravitational analysis.     

Synthesis and characterization of novel soluble and thermally stable polyamides based on pyridine monomer

Nucleophilic aromatic substitution reaction of 4-aminophenol and also 5-amino-1-naphthol with 2,6-dichloropyridine in N-methyl-2-pyrrolidone (NMP) as solvent, in the presence of potassium carbonate, afforded two aromatic ether diamines. Eight soluble, thermally stable polyamides were prepared by polycondensation reaction of the obtained diamines with aromatic and aliphatic diacid chlorides including terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), adipoyl chloride (AC), and sebacoyl chloride (SC). The prepared monomers and polymers were characterized by conventional spectroscopic methods. Physical and thermal properties of the polymers, such as thermal behavior, thermal stability, solution viscosity, and solubility behavior were also studied.     

Synthesis and properties of polyketones containing thiophene links

A series of polyketones containing thiophene links was synthesized by the Friedel-Crafts polymerization of these dithienylalkanes with aromatic diacid chlorides or dicarbonyl chlorides comprising thiophene links with diphenyl compounds. The resulting polymers had inherent viscosities in the range of 0.11–0.27 dL/g and showed poor solubilities to common organic solvents except strong acids. These thiophene-based polyketones exhibited fairly good thermal stabilities. The TGA data revealed 5% weight losses at 375–450°C and residual weights at 500°C were 43–79% under nitorgen. It was found that the thermal stabilities of these polymers were superior to those of polymides or polysulfonamides containing thiophene links and almost comparable to common aromatic polyketones     

New poly(amide-imide)s syntheses. VIII. Preparation and properties of poly (amide-imide)s derived from 2,3-bis(4-aminophenoxy)naphthalene,trimellitic anhydride,and various aromatic diamines

The new polymer-forming diimide-diacid, 2,3-bis(4-trimellitimidophenoxy) naphthalene (I), was readily obtained by the condensation reaction of 2,3-bis (4-aminophenoxy) naphthalene with trimellitic anhydride. A series of novel aromatic poly (amide-imide)s were prepared by the direct polycondensation of diimide-diacid I with various aromatic diamines using triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved calcium chloride. The resultant polymers have inherent viscosities in the range of 0.65–1.02 dL/g at 30°C in N, N-dimethylacetamide. These polymers were readily soluble in various organic solvents and could be cast into transparent, tough, and flexible films. Their casting films showed tensile strength at break up to 86 MPa, elongation to break of 5–9%, and initial moduli up to 2.35 GPa. The wide-angle X-ray diffraction revealed that those polymers containing p-phenylene or p-oxyphenylene group are partially crystalline, and the other polymers are evidenced as amorphous patterns. These polymers show a glass transition in the range of 213–290°C in their differential scanning calorimetry (DSC) traces. The thermal stability of the polymers was evaluated by thermogravimetry analysis, which showed the 10% weight-loss temperatures in the range of 508–565°C in nitrogen and 480–529°C in air atmosphere. © 1994 John Wiley & Sons, Inc.     

Synthesis of ordered copolyamides by the interfacial polycondensation of the hydrolyzate of bisimidazoline with diacid chloride

Ordered copolyamides were prepared by the interfacial polycondensation of the hydrolyzate of bisimidazoline in the aqueous solution with diacid chloride in chloroform solution; bisimidazolines used were 1,4-bis(imidazoline-2-yl)butane and 1,4-bis(imidazoline-2-yl)-octane; diacid chlorides used were adipoyl chloride, sebacoyl chloride, and terephthaloyl chloride. The aqueous solutions of the hydrolyzates of bisimidazolines were prepared by heating the aqueous solutions of imidazolines at 70°C. It was shown by infrared spectra and paper electrophoresis of the hydrolyzates that bisimidazolines were hydrolyzed to give quantitatively diamines containing amides linkages of the type H₂N(CH₂)₂NH-CORCONH(CH₂)₂NH₂. The regularity in the sequence of the copolyamide of nylon 26 and nylon 2T prepared from the hydrolyzate of 1,4-bis(imidazoline-2-yl)butane and terephthaloyl chloride was studied by NMR spectrometry: it was concluded that the copolyamide was highly ordered.     

Synthesis of inherently dissymmetric polyamides,

The preparation of polyamides from derivatives of optically active biphenic acid is described. The diacid chlorides chosen were 2,2′-dinitro-6,6′-dimethylbiphenyl-4,4′-dicarbonyl chloride and 2,2′-dichloro-6,6′-dimethylbiphenyl-4,4′-dicarbonyl chloride, the diamines were phenyldiamines (o-, m-, p-) piperazine, trans-2,5-dimethylpiperazine, and 1,2-piperaazolidine. Polymerization was carried out by the method of interfacial polycondensation. The polymers of aromatic diamines were insoluble in common organic solvents but soluble in dimethylformamide containing 5% lithium chloride, triesters of phosphoric acid, and methanesulfonic acid. The polymers of aliphatic diamines were also insoluble in common organic solvents but soluble in trifluoroethanol. All polymers had melting points higher than 280°C.     

Polyisophthalamides with benzoyl pendent groups: Synthesis,characterization, and evaluation of properties

Polyisophthalamides containing benzoyl pendent groups were prepared from 5-benzoylisophthaloyl chloride and seven aromatic diamines, and their properties were compared with those of unsubstituted polyisophthalamides. The incorporation of one pendent benzoyl group per repeat unit brought about a decrease in the glass transition temperature of 10–30°C, relative to the unmodified polymers, while the thermal resistance (programmed TGA) remained unchanged or went down slightly. Other properties investigated were mechanical properties, solubility, and water absorption. © 1993 John Wiley & Sons, Inc.