Synthesis of polyamides by ring-opening polyaddition of benzobis[1,2]oxazinediones with aliphatic diamines

Novel oxime-containing polyamides have been prepared by the ring-opening polyaddition of combinations of two benzobis[1,2]oxazinediones, 4,6-diphenylbenzo[1,2-d:5,4-d′]bis[1,2]oxazine-1,9-dione and 4,9-diphenylbenzo[1,2-d:4,5-d′]bis[1,2]oxazine-1,6-dione, with two aliphatic diamines in a polar aprotic solvent such as N-methyl-2-pyrrolidone. The polymerization was almost completed within a day at room temperature. These polymers had inherent viscosities in the range of 0.12–0.38 and were soluble in a wide range of solvents, including formic acid and hot m-cresol, as well as a number of polar aprotic solvents. All the polymers softened at a temperature ranging from 165 to 185°C. Thermal characterization of the polyamides by TGA and DTA showed polymer decomposition temperatures of about 240°C in air.     

Synthesis of polyamides by ring-opening polyaddition: Reaction of 4,4′-disubstituted bisazlactones with diamines

Ring-opening polyaddition of 4,4′-disubstituted bisazlactones with various diamines was carried out in N-methyl-2-pyrrolidone to afford polyamides with pendant amide group having inherent viscosities of 0.17-0.51 in quantitative yields. The solution polymerization with aliphatic diamines was almost complete at room temperature within 24 hr. Nearly all of the polyamides were soluble in polar in polar aprotic solvents and in acidic solvents. These polymers began to decompose at around 200–300°C as determined by DTA and TGA under nitrogen.     

Phenazasiline-containing polyamides and polyesters

A Phenazasiline ring was incorporated into a polymer backbone by polycondensation of 2,8-dichloroformyl-5,10-dihydro-5-methyl-10,10-diphenylphenazasiline (V) with aromatic diamines or bisphenols, and phenazasiline-containing polyamides and polyesters were obtained. The polyamides were prepared by low-temperature solution polycondensation in N-methyl-2-pyrrolidone (NMP) in the presence of lithium chloride. The polyesters were synthesized by interfacial polycondensation in a mixture of 1,2-dichloroethane and aqueous alkali in the presence of tetrabutylammonium chloride as an accelerator. These reaction conditions gave the corresponding polymers with high viscosities. The phenazasiline-containing polyamides exhibited good solubilities in polar aprotic solvents such as dimethylformamide, dimethylacetamide, and NMP, and also in m-cresol, although the polyesters showed limited solubilities in organic solvents. Under nitrogen, the phenazasiline-containing polyamides and polyesters showed little degradation below 400°C and had good heat resistance.     

METAL ADHESIVE PROPERTIES OF POLYAMIDES HAVING 4,5-DI(1,4-PHENYLENE)-IMIDAZOLEDIYL STRUCTURE

Polyamides were synthesized by the direct polycondensation of aromatic diamines containing 4,5-imidazolediyl structure with aliphatic dicarboxylic acids, and the metal adhesive properties of these polymaides were studied. The inherent viscosity of the obtained polyamides was in the range of 0.28 to 0.71 dl g^?1. The decomposition temperatures (T _ds) of the obtained polyamides were above 400°C and their glass transition temperatures (T _gs) were from 168 to 198°C. These polyamides also showed good solubilities in polar solvents, such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and formic acid. A standard tensile test was performed in order to examine the adhesive property of these polyamides for stainless steel, and the obtained polyamides showed excellent tensile strengths, e.g. polyamide P1s derived from 4,5-di(4-aminophenyl)imidazole (DAPI) and sebasic acid had values of 212 kgf cm^?2 at 20°C, 183 kgf cm^?2 at 120°C, and 133 kgf cm^?2 at 180°C. A commercially available epoxy resin was also examined, and showed great tensile strength at 20°C. However, the strength of the epoxy resin was found to decrease with increasing temperature, whereas polyamide having 4,5-imidazolediyl structure retains its strength at temperatures of up to 180°C. In addition, the polyamide was also derived from 4,4″-diamino-o-terphenyl(DAOT) (rather than DAPI) and sebasic acid, and the properties of the polyamides derived, respectively from DAPI and DAOT were compared.     

Synthesis of polyamides by ring-opening polyaddition of bis-3,1-benzoxazin-4-ones with aliphatic diamines

Open-chain polyamides with inherent viscosities of 0.1–0.6 were prepared in nearly quantitative yields by the ring-opening polyaddition of combinations of six bis-3,1-benzoxazin-4-one monomers and two aliphatic diamines in polar aprotic solvents at 80°C or below. The polymerization carried out in dimethyl sulfoxide at 80°C was best for preparing high-molecular-weight polymers. These polyamides were generally soluble in polar aprotic solvents, m-cresol, and pyridine.     

Synthesis of polyamides from pseudo dibenzoylphthaloyl chlorides and aliphatic diamines

New pseudo dibenzoylphthaloyl chlorides, namely, 2,5-dibenzoylterephthaloyl, 4,6-dibenzoylisophthaloyl, and 4,6-di(p-toluyl)isophthaloyl chlorides, were synthesized as monomers. The ring-opening polyaddition reaction of the pseudo dibenzoylphthaloyl chlorides with aliphatic diamines in N-methyl-2-pyrrolidone afforded a new class of polyamides having inherent viscosities of 0.2 ～ 0.6 in quantitative yield. The solution polymerization was almost completed within 30 min at room temperature. All of the polyamides were soluble in a wide range of solvents including tetrahydrofuran. These polymers began to decompose at around 300°C both in air and under nitrogen as determined by differential thermal analysis (DTA) and thermogravimetric analysis (TGA).     

Synthesis of polyarylamines by vinylogous nucleophilic substitution polymerization of bis(4-chloro-3-nitrophenyl) sulfone with diamines

A series of new polyarylamines was prepared by the vinylogous nuclephilic substitution polymerization of bis(4-chloro-3-nitrophenyl) sulfone with both aromatic and aliphatic diamines. The synthesis involves the solution polycondensation in a polar aprotic solvent at elevated temperatures, a tertiary amine being used as an acid acceptor. Of these solvents, dimethyl sulfoxide and N-methyl-2-pyrrolidone were the most effective for the preparation of high molecular weight polymers. The polyarylamines having inherent viscosities in the range of 0.1–0.5 were all amorphous and highly soluble in polar aprotic solvents. Thermogravimetric analysis under both air and nitrogen atmospheres indicated that rapid decomposition began above 300°C for the polyarylamines from aromatic diamines.     

Synthesis of polyamides from active 1-benzotriazolyl diesters and diamines under mild conditions

The effect of the solvent on the inherent viscosity of polyamides was investigated in the polycondensation of new active 1-benzotriazolyl diesters, such as 1,1′-(adipolydioxy)bisbenzotriazole and 1,1′-(isophthaloyldioxy)bisbenzotriazole, with diamines. The preferred polymerization media were polar aprotic solvents, including N-methyl-2-pyrrolidone and hexamethylphosphoramide. The solution polycondensation at room temperature afforded a series of polyamides having inherent viscosities as high as 1.8 from both aliphatic and aromatic diamines. The 1-benzotriazolyl diesters were more reactive than di(2,4-dinitrophenyl) isophthalate toward diamines. Prior to polymer synthesis, the aminolysis of some active monoesters was carried out as a model compound study.     

Preparation and Properties of Novel Aromatic Polyamides from Diamines Containing 4,5-Imidazolediyl Structure

Novel aromatic polyamides were prepared from aromatic diamine containing 4,5-imidazolediyl unit, either by low temperature solution polycondensation or by direct polycondensation. Used diamines were 4,5-bis(4-aminophenyl)-2-phenylimidazole 1, 4,5-bis[4-(4-aminophenyl)]-2-(4-methylphenyl)imidazole 2 and 4,5-bis[4-(4-aminophenoxy)phenyl]-2-phenylimidazole 3. The obtained aromatic polyamides were produced with moderate to high inherent viscosity and soluble in polar aprotic solvents such as N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Thermogravimetric analysis showed those polymers were stable up to 422°C in nitrogen atmosphere. The glass transition temperature (T _g)s of the polymers derived from diamine 3 were in the range between 243 and 275°C, and these values were approximately 120–160°C lower than those analogue polyamide I series containing no phenoxy units. The properties of polyamide I series are also compared with those of analogue polymers that order of aromatic nuclei and amide linkage is reversible.     

Synthesis and Properties of Polyamides and Polyimides Derived From Diamines Having 2-Phenyl-4,5-Oxazolediyl Units and Polyamide/Montmorillonite Composite

Aromatic polyamides were synthesized from 4,5-bis(4-aminophenyl)-2-phenyloxazole (APO) or 4,5-bis[4(4-aminophenoxy)phenyl]-2-phenyloxazole (APPO) containing 2-phenyl-4,5-oxazolediyl units with several aromatic carboxylic dichlorides by a low-temperature solution polycondensation method. The polyamides were obtained quantitatively, and their inherent viscosities ranged from 0.48 to 1.25 dL g^?1. The glass transition temperatures (T _gs) were displayed between 234 to 311°C, and the residual weight at 600°C (Res.wt₆₀₀) exceeded 52% in nitrogen atmosphere. The polyamides showed good solubility in several aprotic polar solvents, such as N,N-dimethylacetoamide (DMAc), N-methyl-2-pyrrolidone (NMP), and dimethyl sulfoxide (DMSO). Aromatic polyimides were derived from APO or APPO with aromatic carboxylic dianhydrides through polyamic acids. The inherent viscosities of the polyamic acids, which were 0.53 to 1.02 dL g^?1, T _gs of the polyimides were observed between 259 to 361°C and their Res.wts₆₀₀ were above 70%. The polyamides and polyimides were amorphous and afforded thin, flexible and tough films. We also prepared a nanocomposite of the polyamide derived from APPO with organophilic montmorillonite clay.     

Synthesis of polyacylsulfonamide-amides by ring-opening polyaddition of N,N′-arylenedisulfonylbissuccinimides with diamines

Ring-opening polyaddition of N,N′-arylenedisulfonylbissuccinimides with both aliphatic and aromatic diamines in N-methyl-2-pyrrolidone at room temperature afforded polyacylsulfonamide-amides having inherent viscosities in the range of 0.2–0.4 in excellent yields. The polymers revealed acidic nature and were readily soluble in both polar aprotic solvents and basic media. They melted at a temperature below 200°C and began to decompose at around 250°C in nitrogen.     

Synthesis and properties of aromatic polyamides derived from 1,7-bis(4-aminophenoxy)naphthalene and various aromatic dicarboxylic acids

A series of novel bis(phenoxy)naphthalene-containing polyamides having inherent viscosity up to 2.02 dL/g were synthesized by the direct polycondensation of the diamine 1,7-bis(4-aminophenoxy)naphthalene with various aromatic dicarboxylic acids in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Most of the polyamides could be readily dissolved in polar aprotic solvents such as N,N-dimethylacetamide and NMP, and could be solution-cast into transparent, flexible, and tough films. These polymers had glass transition temperatures in the range of 139–263°C, and 10% weight loss temperatures in nitrogen and air were above 499 and 484°C, respectively. © 1996 John Wiley & Sons, Inc.     

Syntheses of polyamides and polybenzodipyrrolediones from pseudo diacetylphthaloyl chlorides and diamines

Novel diacetylphthalic acids, 2,5-diacetylterephthalic and 4,6-diacetylisophthalic acids, were synthesized starting from pyromellitic dianhydride. These diacids were subsequently converted to the corresponding pseudo diacetylphthaloyl chlorides. The ring-opening polyaddition, followed by dehydrochlorination, of the pseudo diacetylphthaloyl chlorides with aliphatic diamines in a polar aprotic solvent afforded almost quantitatively polyamides having inherent viscosities of 0.3–0.7. The solution polymerization was almost completed within 1 hr at room temperature. These polyamides were soluble in acidic solvents like m-cresol. Subsequent cyclodehydration of the polyamides by heating at 200°C gave insoluble polybenzodipyrrolediones, which underwent weight losses of 10% at around 400°C under nitrogen.     

Phenoxasilin-containing polyamides and polyesters

Silicon-containing polyamides and polyesters of a new type have been synthesized. They contain phenoxasilin rings with double-stranded structure. The polymers were synthesized by the interfacial polycondensation of 2,8-dichloroformyl-10,10-diphenylphenoxasilin with diamines and bisphenols, and were obtained in nearly quantitative yields. Their reduced viscosities were in the range of 0.53–1.47 dl g^?1 m dimethylformamide (DMF), m-cresol or chloroform. Some of the polyamides were soluble in polar aprotic solvents such as DMF and N-methyl-2-pyrrolidone (NMP) and the polyesters had good solubility in chloroform, phenol-sym tetrachloroethane (60:40 by wt %) and acidic solvents (m-cresol and nitrobenzene). The polymers hardly dissolved in cone. H₂SO₄ and some of them coloured in it. Only the polyester having sulphide bonds was soluble in benzene in addition to the above organic solvents. These polymers hardly degraded below 400° except for the polyamides derived from aliphatic diamines. The polymers from aliphatic diamines melted at 290–325°; the other polyamides and the polyesters decomposed without melting.     

Modification of polymers via electrophilic aromatic substitution

Three vinyl monomers, 2,4,6-trimethoxystyrene, 4-(N,N-dimethylamino)styrene, and N-methyl-2-vinylpyrrole, were synthesized via the Wittig reaction from the corresponding aldehyes. These monomers were homopolymerized by radical polymerization using α,α′-azoisobutyronitrile (AIBN) as initiator at 60°C. The reaction of these polymers with 4-phenyl-1,2,4-triazoline-3,5-dione (phTD) and 4-methyl-1,2,4-triazoline-3,5-dione (MeTD) was investigated. Although polytrimethoxystyrene reacts slowly with PhTD at room temperature, the other two polymers react fast and lead to the incorporation of the triazolinedione unit into the side chain of the polymer via electrophilic aromatic substitution. The reaction of bistriazolinediones (BTD) with these polymers was performed in dimethylformamide using 10–20% molar concentration of the BTD. The resulting crosslinked polymers are insoluble in polar as well as nonpolar solvents. Some physical properties of the unmodified and modified polymers were studied.     

Preparation and properties of polyamides from 2,2′-p-phenylenebis-5-oxazolones with diamines

Novel phenylated polyamides having inherent viscosities in the range of 0.2–0.4 were prepared by the ring-opening polyaddition of 2,2′-p-phenylenebis(4,4-diphenyl-5-oxazolone) with aliphatic diamines in polar aprotic solvents. Similarly, unsubstituted polyamides were obtained from 2,2′-p-phenylenebis-5-oxazolone and both aliphatic and aromatic diamines. The phenylated polyamides were highly soluble in a wide range of solvents including tetrahydrofuran and dioxane, while the unsubstituted polymers showed limited solubility in the solvents. No marked differences in thermal stability between the phenylated and unsubstituted polyamides were noted, and all the polyamides began to decompose at around 250°C in both air and nitrogen.     

Synthesis and structure of dihydro-1,2,4-triazin-6(1H) ones

Reactions of the iminoesters 3a-c with hydrazine or 1,2-dimethylhydrazine gave 4,5-dihydro- 4a-c or 2,5-dihydro-1,2,4-triazin-6(1H) ones 7a-c , respectively. When methylhydrazine was employed, 1-methyl-4, 5-dihydro- 5a-c and 2-methyl-2,5-dihydro-1,2,4-triazin-6(1H) ones 6a-c were obtained. Compounds 6a-c exist as zwitterions in the solid state and in polar aprotic solvents.     

Preparation and properties of aromatic poly(amide–benzothiadiazine dioxides)

New thermostable poly(amide–benzothiadiazine dioxides) of high molecular weights have been prepared by the two-step cyclopolycondensation of diaminobenzenesulfonamides and aromatic bisacyl chlorides. In the first step, the low-temperature solution polymerization technique afforded open-chain polyamides (I) having high molecular weights. In the second step, the polymeric precursors (I) underwent chemical cyclodehydration in the presence of organic basic catalysts at 160°C to give poly(amide–benzothiadiazine dioxides) (II), whereas thermal cyclodehydration gave unsatisfactory results. Not only the open-chain polymers (I) but also the cyclized polymers (II) were soluble in polar solvents, such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone; tough films were cast from these solutions. Thermogravimetric analyses indicated that the cyclized polymers (II) began to decompose at 450–470°C under nitrogen or in air. It is interesting to note that both polymers I and II exhibited self-extinguishing properties against free flame. The cyclodehydration of model compounds was also investigated.     

Synthesis of polybenzamide–ureas from N-mesyloxyphthalimide and diamines

Novel polybenzamide-ureas have been synthesized by the polymerization of N-mesyloxyphthalimide with diamines in N-methyl-2-pyrrolidone in the presence of acid acceptors. The polymerization probably proceeds through the formation of ring-opened adducts, followed by elimination and rearrangement yielding 2-isocyanatobenzamide derivatives, which were subsequently reacted to give polybenzamide-ureas. These polymers had inherent viscosities of 0.12–0.34 and were soluble in a wide range of solvents, including pyridine and m-cresol, as well as polar aprotic solvents. All of the polymers had low softing temperatures in the range of 140–260°C, and thermal analyses showed that marked decomposition of the polymers occurred at around 200–300°C, presumably forming quinazolinedione rings by intramolecular deamination.     

Syntheses of polyamides and polypyrrolones from 2,2′-disubstituted bis(3-buten-4-olides) and diamines

The ring-opening polyaddition of 2,2′-disubstituted bis(3-buten-4-olides) with aliphatic diamines in m-cresol at room temperature afforded in quantitative yields polyamides with a pendant ketone moiety having inherent viscosities of up to 0.7. On the other hand, the polymerization in m-cresol at 80°C with acidic catalysts and at 160°C without any catalyst yielded directly polypyrrolones, a novel class of polyheterocycles. The cyclodehydration of the open-chain polyamides to polypyrrolones was also achieved by simply treating the polyamide films with methanolic hydrochloric acid at room temperature. Both of the polymers were generally soluble in hot polar solvents such as dimethylformamide, m-cresol, and nitrobenzene. The polypyrrolones began to lose weight gradually at around 250°C in nitrogen as determined by thermogravimetric analysis, while the thermograms in air showed an appreciable weight increase at about 230°C.