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.     

Imine- and Amine-Type Macrocycles Derived from Chiral Diamines and Aromatic Dialdehydes

The condensation of aromatic dialdehydes with chiral diamines, such as 1,2-trans-diaminocyclohexane, leads to various enantiopure or meso-type macrocyclic Schiff bases, including [2 + 2], [3 + 3], [4 + 4], [6 + 6] and [8 + 8] condensation products. Unlike most cases of macrocycle synthesis, the [3 + 3] macrocycles of this type are sometimes obtained in high yields by direct condensation without a metal template. Macrocycles of other sizes from this family can often be selectively obtained in high yields by a suitable choice of metal template, solvent, or chirality of the building blocks. In particular, the application of a cadmium(II) template results in the expansion of the [2 + 2] macrocycles into giant [6 + 6] and [8 + 8] macrocycles. These imine macrocycles can be reduced to the corresponding macrocyclic amines which can act as hosts for the binding of multiple cations or multiple anions.     

Stereocomplex Formation from Enantiomeric Polyamides Derived from Tartaric Acid

Summary: The formation of stereocomplexes from the pair of enantiomorphs of the chiral polyamide poly(hexamethylene di‐O‐methyl tartaramide) was investigated for a variety of experimental conditions. DSC and X‐ray diffraction data evidenced that efficiency in enantiomeric association is highly sensitive to the procedure used for preparing the complex. A comparative isothermal crystallization study revealed that the stereocomplex crystallized from the melt at a rate lower than the enantiomerically pure components. The radial growth of individual spherulites was also delayed in the crystallization of the complex. No evidence of stereocoupling was detected for other poly(alkylene di‐O‐methyl tartaramide)s with the alkylene unit length different from six. It was concluded that molecular interlocking of hydrogen bonds in the enantiomeric pair is highly selective in this family of polymers.

Spherulitic growth at 200 °C from the melt.     

Soluble and Colorless Polyimides from Alicyclic Diamines

Abstract

A series of novel polyimides was synthesized from alicyclic diamines and various aromatic dianhydrides by one-step polymerization in m-cresol without a catalyst. The polymerization was conducted for 4 hours with refluxing, which was enough to obtain the polymers with high molecular weight. The inherent viscosities of the resulting polyimides were in the range of 0.30 ～1.29 dL/g. The prepared polyimides showed excellent thermal stabilities and good solubility. All the polymers were readily soluble in common organic solvents such as chloroform, tetrachloroethane (TCE), dimethylacetamide (DMAc), etc and the glass transition temperatures were observed at 199 to 311°C. UV-visible spectra were obtained to measure the transparency of polymer films. All the polymers showed high transmission above 90% in the wavelength of 400 ～700 nm.     

Aromatic-Aliphatic Polyimides. I. Preparation and Properties of Polypyromellitimides from Aromatic Diamines and Oxalyl Dihydrazide

Copolyimides were prepared in two steps by ring-opening polyaddition of pyromellitic dianhydride (PMDA) with oxalyl dihydrazide (0) and an aromatic diamine; viz., diaminodiphenyl methane (M), p-phenylene diamine (P), or benzidine (B) in dimethylsulfoxide (DMSO), followed by thermal cyclodehydration. O content was restricted to 10%. Kinetics of imidization of polyamic acid samples was studied. The effect of structure and composition of copolymers on thermal properties was evaluated.     

p-Xylylenediamine and New Polyimides Derived from It

p-Xylylenediamine was prepared by hydrogenation of terephthalodinitrile; the conditions ensuring high yield of this monomer were found. The influence exerted by the catalyst and solvent on the diamine yield was examined. Single-step polycondensation of p-xylylenediamine with tricyclodecenetetracarboxylic dianhydrides in the presence of catalytic amounts of isonicotinic acid gave a series of new polyimides consisting of aliphatic and aromatic fragments.     

Synthesis and Characterization of New Soluble Polyamides from 9,9-Bis[4-(chloroformylphenoxy)phenyl]xanthene and Various Aromatic Diamines

9,9‐Bis(4‐hydroxyphenyl)xanthene (BHPX) was synthesized in 82% yield from xanthenone in a one‐pot, two‐step synthetic procedure. A new diacyl chloride monomer, 9,9‐bis[4‐(chloroformylphenoxy)phenyl]xanthene (BCPX), was synthesized in three steps from the nucleophilic fluorodisplacement of 4‐fluorobenzonitrile with the dipotassium bisphenolate of BHPX, followed by alkaline hydrolysis of the intermediate bis(ether nitrile), and then chlorination with thionyl chloride. Several novel aromatic polyamides containing ether and bulky xanthene groups with the inherent viscosities (0.72–0.98 dL/g) were prepared by the low temperature polycondensation of BCPX with various aromatic diamines in N,N‐dimethylacetamide (DMAc) solution containing pyridine (Py). All new polyamides were amorphous and readily soluble in various polar solvents such as DMAc, N,N‐dimethylformamide (DMF), N‐methyl‐2‐pyrrolidone (NMP) and Py. These polymers showed relatively high glass transition temperatures between 236 and 298°C, decomposition temperatures at 10% weight loss ranging from 490 to 535°C and 483 to 515°C in nitrogen and air, respectively, and char yields at 700°C in nitrogen higher than 50%. Transparent, flexible, and tough films of these polymers cast from DMAc solutions exhibited tensile strengths ranging from 82 to 106 MPa, elongations at break from 10% to 25%, and initial moduli from 2.0 to 2.8 GPa.     

Hydrolytic Stability of Films of Aromatic Polyimides and Composites on Their Basis,Filled with Carbon Nanocones

Variation of the mechanical and thermal characteristics of poly(4,4′-oxydiphenylenepyromellitimide) and poly{1,3-bis(3′,4-dicarboxyphenoxy)benzene [4,4′-bis)4′-N-phenoxydiphenylsulfone]imide} films and nanocomposites based on these polyimides and filled by carbon nanocones/disks in the course of hydrolysis in an alkaline solutions was studied. The goal of the study was to obtain systematic information about the influence exerted by carbon nanoparticles introduced into polyimide films with varied chemical structure on the stability of the resulting film materials against a prolonged action of active hydrolyzing media. It was shown that the hydrolytic stability of the materials under study is largely determined by the molecular packing density. Introduction of nanoparticles into the polymers under study may result in that the concentration in the material of the excess free volume localized at polymer–filler interfaces increases. This, in turn, causes a decrease in the hydrolytic stability of the nanocomposite film as compared with unfilled films of the matrix polyimide. The opportunity was considered of raising the hydrolytic stability of the polyimide and nanocomposite material by making higher the average packing density.     

Synthesis and Properties of Polyamides,Polyimides, and a Polyamide-Imide Based on Trimethylene Glycol-Di-p-Aminobenzoate

New polyamides, polyimides, and a polyamide-imide containing ester linkages were prepared by the reaction of trimethylene glycol di-p-aminobenzoate with terephthaloyl chloride, isophthaloyl chloride, adipoyl chloride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and trimellitoyl chloride. the low temperature solution and interfacial polymerization techniques were utilized to prepare the above-mentioned polymers. the polymers thus prepared were found to be soluble in solvents like DMAC and DMSO and had inherent viscosities in the 0.15-0.60 range. the polyimides prepared formed transparent and flexible films.     

Polyamides from Aromatic Bisamines-Chloral Derivatives and Terephthaloyl Chloride by Polycondensation in Solution

New aromatic polyamides from the bisamines 2,2-bis(p-amine-pheny1)-1, 1,1-trichloroethane (Bisamine I), 2,2-bis(p-amine-pheny1)-1,1-dichloroethylene (Bisamine II), and terephtaloil chloride were synthesized by means of several methods. It was found that low-temperature solvent polycondensation is optimum for obtaining polymers with the best properties, which are predominantly better in the case of polyamides based on Bisamine II.     

Synthesis,Structure, and Fungicidal Activity of Organotin Dithiocarbamates Derived from Pyridinamines and Aryl Diamines

A reaction of N‐benzylpyridinamines with n‐BuLi, followed by a reaction with CS₂ and R₃SnCl or R₂SnCl₂ (R = n‐Bu, PhCH₂, or Ph) gave a series of mononuclear organotin dithiocarbamates. A similar reaction of N,N'‐bis(benzyl)‐1,3‐benzenediamine and N,N'‐bis(benzyl)‐2,6‐pyridinediamine afforded dinuclear and macrocyclic organotin dithiocarbamates. All of these complexes were characterized by elemental analysis, IR, and multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn). Their structures have been confirmed by the X‐ray single crystal diffraction analysis, suggesting the dithiocarbamate groups acted as anisobidentate chelating ligands in these complexes. The primary fungicidal activity of these complexes was tested in vitro, showing that most complexes displayed good antifungal activity to Sclerotinia sclerotiorum.     

新型超支化聚芳酰胺的合成及表征

以3，5—二硝基苯甲酰氯和对氨基苯甲酸为原料，经两步反应合成了新型AB2型单体4—(3，5-二氨基苯甲酰氨基)苯甲酸。在溶液中通过自缩聚反应合成了新型超支化聚芳酰胺，将其活性端氨基与酰氯反应，经原位改性合成了五种封端的超支化聚芳酰胺，并利用IR、^1HNMR、DSC及TG等方法对所合成的六种新型超支化聚合物的结构和性能进行了表征与测试。     

Polyamides from Aromatic BisaminesChloral Derivatives and Terephthaloyl Chloride by Interfacial Polycondensation

Investigations on a new class of polyamides obtained by interfacial polycondensation from amine-chloral derivatives, e.g., 2,2-bis(p-aminophenyl)-1,1,1-trichloromethane or 2,2-bis(p-aminophenyl)-1, 1-dichloroethylene and terephthaloyl chloride, have been carried out. It was found that the interfacial process proceeds in the most advantageous way in acidic medium at 0°C using equivalent volume amounts and equimolar concentrations of methylene chloride and water phases in the presence of a stoichiometric quantity of triethylamine as the hydrogen acceptor.     

Preparation of Polyimides Via the Palladium-Catalyzed Carbonylation and Condensation of Tetraiodoaromatics and Diamines

Several polyimides were prepared by the palladium-catalyzed carbonylation and condensation of tetraiodoaromatic compounds and diamines. This new reaction for preparing polyimides was verified in model compound work to be an efficient, high yield route to cyclic imides. Since fully imidized groups are formed during the polymerization, it was necessary to limit the diamines to those that would impart solubility to the polymer. In contrast to the model compound work, the polymerization reaction yielded an appreciable concentration of amide functional groups due to incomplete cyclization and/or branching reactions. Thermal characterization of the polyimides formed by this process is reported.     

二甲基苯二胺芳香聚酰胺的结构与性能

利用ＩＲ，ＷＡＸＤ，ＤＳＣ及ＴＧ等表明了多取代芳香族聚酰胺的结构与性能。     

三甲基苯二胺芳香聚酰胺的结构与性能

利用ＩＲ，ＷＡＸＤ，ＤＳＣ及ＴＧ等表征了多取代芳香族聚酞胺的结构与性能。     

Four Novel 30-Membered Imine and Amine Macrocycles Derived from Ortho-Aminophenyl Diamines

Two novel macrocyclic tetra-imine-diphenol Schiff base (H₂L₁ and H₂L₂) were synthesized by [2 + 2] cyclocondensation of ortho-aminophenyl diamines [1,2-bis(2′-aminophenoxy)benzene (I) and 1,2-bis(2′-aminophenoxy)-4-t-butylbenzene (II)] with 2,6-diformyl-4-methylphenol. Two novel tetra-amine-diphenol macrocycles (H₂L₃ and H₂L₄) have been obtained by reduction of the imine analogs with NaBH₄ in MeOH/CHCl₃.     

含叔丁基可溶性芳香聚酰胺的制备及其性能研究

采用含叔丁基二胺的单体3,3′-二叔丁基-4,4′-二氨基二苯基-4″-叔丁基苯基甲烷(TADBP)分别与萘-1,4-二甲酸、间苯二甲酸和4,4-二苯醚二甲酸3种二酸单体通过Yamazaki膦酰化法缩聚制得一系列新型可溶性芳香聚酰胺(PA)。通过FT-IR、~1 H-NMR、TG、DSC等测试手段研究了含叔丁基芳香聚酰胺的结构与性能,以及聚合物结构对其溶解性能、热性能的影响。结果表明:PA具有优异的溶解性能,常温下不仅能溶于高沸点的N-甲基吡咯烷酮(NMP)、N,N-二甲基乙酰胺(DMAc)、N,N-二甲基甲酰胺(DMF)、二甲基亚砜(DMSO)等强极性溶剂中,加热条件下甚至能溶于四氢呋喃、氯仿、二氯甲烷等低沸点溶剂;同时,PA还具有良好的热性能,玻璃化转变温度(Tg)为188~193℃,氮气氛围下失重5%和10%时的热失重温度分别为391~416℃和404~437℃。