Preparation and properties of some cardopolyamides

Several polyamides that contained cardo units were prepared. Thus 9,9-bis(4-aminophenyl)fluorene and 9,9-bis(4-aminophenyl)anthrone were condensed with 2,5-dimethyl-1,4-benzenediacetyl chloride, 2,4-dimethyl-1,4-benzendiacetyl chloride, and 2,5-dimethoxy-1,4-benzediacetyl chloride. Lowtemperature solution polycondensation in dimethyl acetamide (DMAc) was used throughout. The polymers were obtained in 80–90% yield and possessed intrinisic viscosities in the range of 0.6–1.2. The polymers were characterized by infrared (IR) spectra and elemental analysis. The solubility, crystallinity, and thermal stability of the polyamides were also determined.     

Crystal structures of 2,4-dimethylthioxanthene 10,10-dioxide, 2,4,9-trimethylthioxanthene 10,10-dioxide,and 2,4-dimethyl-9-isopropylthioxanthene 10,10-dioxide

The structures of 2,4-dimethylthioxanthene 10,10-dioxide, 1 , 2,4,9-trimethylthioxanthene 10,10-dioxide, 2 , and 2,4-dimethyl-9-isopropylthioxanthene 10,10-dioxide, 3 , have been determined by x-ray diffraction. The central ring of the thioxanthene ring system is in a boat conformation. The 9-methyl substituent in 2 and the 9-isopropyl substituent in 3 are both in the boat-axial conformation with respect to the central ring. The folding angles between the planes of the two benzo rings are 136.6°, 142.9°, and 134.3° for 1, 2 , and 3 , respectively.     

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.     

Preparation and properties of polyamides containing thianthrene units

New polyamides containing thianthrene tetraoxide were synthesized from 2,7-dichloroformylthianthrene-5,5′,10,10′-tetraoxide (A) and various diamines by the low temperature solution polycondensation technique. The resulting polyamides were characterized by i.r. and ¹H-NMR spectra and elemental analysis. The polyamides had inherent viscosities of 0.56–1.21 dl/g in DMA at 30°. All the polymers dissolved readily at room temperature in polar aprotic solvents. Density, crystallinity and thermal stability of these polyamides have been determined. In order to characterize the polymers, a model compound was also prepared from A and p-toluidine.     

Preparation of phosphorus-containing polymers—XVII. Preparation of polyamides containing phenoxaphosphine rings

New phenoxaphosphine-containing polyamides were prepared from 2,8-dichloroformyl-10-phenylphenoxaphosphine 10-oxide (III) and aromatic diamines in DMA by low-temperature solution polycondensation in the presence of triethylamine as acid acceptor. (III) was synthesized by the chlorination of 2,8-dicarboxy-10-phenylphenoxaphosphine 10-oxide derived from 2,8-dimethyl-10-phenylphenoxaphosphine 10-oxide by pyridine-permanganate oxidation. The resulting polyamides had a reduced viscosity of 0.14–0.40 dl/g in DMA or conc. H₂SO₄ at 30°. They were soluble in conc. H₂SO₄ and some of them dissolved in DMA, DMF and DMSO, but all were insoluble in benzene and formic acid, etc. They had good thermal stability, hardly degrading until a temperature of about 400° was reached; they showed resistance to ignition.     

Preparation and properties of polyamides and polyimides containing phenoxathiin units

Novel polyimides and polyimides having phenoxathiin units have been prepared. Polyamides with inherent viscosities in the range of 0.5–2.9 were readily prepared by the polycondensations of phenoxathiin diamines with aromatic diacyl chlorides and of aromatic diamines with new phenoxathiin diacyl chlorides. The polyimides were synthesized from phenoxathiin diamines and pyromellitic dianhydride by using a two-step procedure. The polyamic acids which formed in the first step had inherent viscosities ranging from 1.0 to 1.6, and they were converted to the polyimides by thermal cyclodehydration. Some of the phenoxanthiin-containing polyamides were highly soluble in polar amide solvents and dimethyl sulfoxide. A series of novel polymers containing phenoxathiin units were much more thermostable than the corresponding polymers having open-chain diphenyl ether linkages.     

Efficient deep-blue light-emitting polyfluorenes based on 9,9-dimethyl-9H-thioxanthene 10,10-dioxide isomers

We have designed and synthesized a series of deep-blue light-emitting polyfluorenes, PF-27SOs and PF-36SOs, by introducing electron-deficient 9,9-dimethyl-9H-thioxanthene 10,10-dioxide isomers (27SO and 36SO) into the poly(9,9-dioctylfluorene) (PFO) backbone. Compared with PFO, the resulting polymers exhibit an equivalent thermal decomposition temperature (>415 °C), an enhanced glass transition temperature (>99 °C), a decreased lowest unoccupied molecular orbital energy level (E_LUMO) below −2.32 eV, a blue-shifted photoluminescence spectra in solid film with a maximum emission at ~422 nm, and a shoulder peak at ~445 nm. The resulting polymers also show blue-shifted and narrowed electroluminescence spectra with deep-blue Commission Internationale de L'Eclairage (CIE) coordinates of (0.16, 0.07) for PF-27SO20 and (0.16, 0.06) for PF-36SO30, compared with (0.17, 0.13) for PFO. Moreover, simple device based on PF-36SO30 achieves a superior device performance with a maximum external quantum efficiency (EQE_max = 3.62%) compared with PFO (EQE_max = 0.47%). The results show that nonconjugated 9,9-dimethyl-9H-thioxanthene 10,10-dioxide isomers can effectively perturb the conjugation length of polymers, significantly weaken the charge-transfer effect in donor–acceptor systems, substantially improve electroluminescence device efficiency, and achieve deep-blue light emission.     

Synthesis and some properties of amides of 4-carboxymethyl-2-thiolene 1,1-dioxide

Amides of 4-carboxymethyl-2-thiolene 1,1-dioxide were obtained with aliphatic, heterocyclic, and aromatic amines. A study was carried out on the reactions of these amides with various nucleophilic reagents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1622–1625, December, 1984.     

Synthesis and electrochromic properties of polybismaleimides containing triphenylamine units

The bismaleimide (BMI) monomer containing triphenylamine was prepared firstly. Then BMI was reacted with different diamines by Michael addition to obtain prepolymers, respectively. Finally, polyimides (PIs) were obtained through melting procedure. The effects of the structure of BMI moiety and thermal curing condition on thermal stability of PIs were studied by thermogravimetric analysis. PIs have excellent processing properties for film casting. Cyclic voltammetry of PI films was carried out on an indium-doped tin oxide-coated glass substrate. Results which exhibit two reversible oxidations at 0.71–0.78 and 1.06–1.16 V vs Ag/AgCl. The electrochromic performance was investigated by spectroelectrochemical methods. These anodically coloring polymer films not only showed good electrochromic properties but also exhibited high optical contrast ratio of transmittance with a color changing from yellow to green. After 100 cyclic switches, the polymer films still retained excellent redox and electrochromic activity.     

Polyamides containing thiadiazole units: Synthesis and optical properties

Highly refractive and transparent polyamides containing thiadiazole units have been developed.These polymers were prepared by a polycondensation reaction of 4,4'-(1,3,4-thiadiazole-2,5-thio) bis(methylene) dibenzoyl chloride(TDTBM-DC) and diamine which contained thioether(―S―) and sulfone units.They showed good thermal stabilities such as a relatively high glass transition temperature of 206-233 °C and a 5% weight-loss temperature(T5%) of 376-395 °C.The optical transmittance of the polymer at 450 nm is higher than 83%.The heterocycle units and plural ―S― linkages provide the polymer with a high refractive index of 1.716-1.725 at 633 nm and a low birefringence of 0.003-0.004.Also they showed improved solubility in polar aprotic solvents and could form moderate strength films with tensile strength of 72.8-83.1 MPa and storage modulus of 1.0-1.8 GPa(at 200 °C).     

Preparation and some properties of polyoxathiaferrocenophanes

Some sulfur analogs of a crown ether-like compound containing ferrocene as a ring member were prepared. Their complexing ability was poor with alkali metal cations but good with a silver cation.     

Preparation and properties of some peralkylpolygermanes

Summary The alkylation of trihalogenogermane etherates 2R₂O·GeCl₃ with Grignard reagents RMgBr forms, in addition to tetraalkylgermanes, polyalkylpolygermanes R(GeR₂)_nR having an exclusively linear structure.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1395–1398, June, 1977.     

Synthesis and thermal properties of diurethanes containing various mesogenic units

Abstract

Five homologous series of diurethanes containing mesogenic moieties were synthesized by addition reactions of ω-alkenols to aromatic diisocyanates. The thermal behaviour of the compounds was studied by differential scanning calorimetry and on the hot stage of a polarizing microscope. Thermotropic liquid crystal behaviour was found for the diurethanes having a central core of more than two aromatic rings. Smectic C mesophases were observed for the derivatives of 4,4″-p-terphenylene and nematic mesophases for the diurethanes containing a di(4-phenylene)terephthalate unit. The compounds of both series possess high transition temperatures and narrow mesomorphic ranges.     

Preparation and properties of silicon containing polyamides

Silicon containing polyamides were prepared by melt polycondensation method with a 1,3-bis(3-aminopropyl)tetramethyldisiloxane and aliphatic dicarboxylic acids having various numbers of methylene groups. Only one endothermic peak appeared in the DTA curve of the quenched sample for polyamides having an even number of methylene groups in the repeating unit. Two endothermic peaks, however, appeared for the sample kept for a week in dry air at ambient temperature after quenching: the peak at the higher temperature is called peak I; and the peak at the lower one, peak II. By heat treatment at the higher temperature, peak II shifted to a higher temperature and increased its peak area, and peak I decreased its peak area while keeping its temperature unchanged. This behavior suggests the existence of two types of crystalline states. The peak temperature of peak I alternatively decreased with the increase of the number of methylene groups. The Young's modulus and the tensile strength increased with increase of annealing time at ambient temperature. The solubilities in various solvents, the resistance to alkali solution, and the thermal stability were acceptable. Both the permeation coefficient of oxygen (P) and the separation ratio (P/P) increased with the increase of silicon content in the repeating unit.     

Preparation and properties of silicon containing copolyamides

Copolyamides containing siloxane moieties in main chain were prepared by a melt polycondensation with 1,3-bis(3-aminopropyl)tetramethyldisiloxane (E), hexamethylenediamine (N6), and adipic acid (6). Glass transition temperature (T_g), cold crystallization temperature (T_cc), and melting temperature (T_m) were measured by differential thermal analysis (DTA). The depression of T_m for copolyamide was fitted by the Flory curve. Melting peak remarkably broadens with increasing E6 component in copolyamide. The change of T_g was fitted by the Gibbs and Dimarzio's equation in which the number of flexible bond is considered. The difference between T_g and T_cc increased with increasing E6 component. These DTA studies suggest that the crystallization of N66 component in copolyamide is hindered by the bulky siloxane moiety, while the micro-Brownian motion of amorphous segment is promoted by the flexible siloxane bond. Tensile strength and Young's modulus decreased with increasing E6 component. The solubility in various solvents increased with increasing E6 component. Permeability of oxygen and nitrogen increased with an increase of temperature and E6 component. The separation coefficient of oxygen to nitrogen rapidly increased near 50 mol% of E6 concentration and then leveled out above 70 mol%. The contact angle with water and methylene iodide increased with an introduction of the siloxane moiety into polymer chain.