Preparation of phosphorus-containing polymers—XV. Preparation of phosphorus-containing polyamide-imides from N,N′-bis(4-carboxyphthalimido)-3,3′-diphenylalkylphosphine oxide and aromatic diacetamides

Phosphorus-containing polyamide-imides were prepared from N,N′-bis(4-carboxyphthalimido)-3,3′-diphenylalkylphosphine oxide and aromatic diacetamido derivatives by acidolysis; the reaction conditions are discussed. The resulting polymers were fairly soluble in DMA, DMF and conc. H₂SO₄; the reduced viscosities of polymers in DMA or cone. H₂SO₄ (0.2 g/dl) at 30° were 0.19–0.32. The phosphorus-containing polymers have good thermal stability, and are self-extinguished immediately after the flame is removed. Most of the i.r. absorption bands of polymers vanished on heating at above 600°.     

Preparation of phosphorus-containing polymers—XVI. Synthesis of phosphorus-containing polyanhydride-imides

Phosphorus-containing polyanhydride-imides were synthesized from N,N-bis(4-carboxyphthalimido)-3,3′-diphenylalkylphosphine oxide, 3,3′-[N,N′-bis(4-carboxyphthalimido)]benzophenone and their mixtures in two steps via the diacetyl derivatives of the bisimide-carboxylic acids. The resulting polymers have reduced viscosities of 0.06–0.14 dl/g and are soluble in polar aprotic solvents such as DMA, DMF and DMSO, and conc. H₂SO₄ etc. They have good hydrolytic stability for moisture and water. Phosphorus-containing polymers have little heat-resistance and poor flame-retardance. The benefit of incorporating phosphorus in the polymers is small.     

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 of phosphorus-containing polymers. XXV. Polyamide-imides that contain phenoxaphosphine rings

New phenoxaphosphine-containing polyamide-imides were prepared by cyclodehydration of the polyamide-amic acids obtained from 8-chloroformyl-10-phenylphenoxaphosphine-2,3-dicarboxylic anhydride 10-oxide and diamines by a low-temperature solution polycondensation. Polymers with reduced viscosities of 0.10–0.59 dl/g in DMA or concentrated H₂SO₄ at 30°C were obtained in 64–97% yields. All the polyamide-imides were soluble in m-cresol, concentrated H₂SO₄, and dichloroacetic acid and some of them were soluble in DMF, DMA, and DMSO; the polyamide-imides had better solubility in organic solvents than phenoxaphosphine-containing polyimides. The phenoxaphosphine-containing polyamide-imides derived from aromatic diamines exhibited excellent thermal properties and little degradation below about 400°C, whereas the polymers from aliphatic diamines began to lose weight at about 250°C. They appeared to have thermal stability between phenoxaphosphine-containing polyimides and polyamides. These polyamide-imides exhibited self-extinguishing behavior.     

Preparation of phosphorus-containing polymers—XXIII: Phenoxaphosphine-containing polyimides

New phenoxaphosphine-containing polyimides were synthesized from 10-phenylphenoxaphosphine-2,3,7,8-tetracarboxylic dianhydride 10-oxide (IV) and diamines via polyamic acids in two steps. (IV) was prepared by dehydration of 10-phenylphenoxaphosphine-2,3,7,8-tetracarboxylic acid 10-oxide (III) derived from 2,3,7,8-tetramethyl-10-phenylphenoxaphosphine (I) or 2,3,7,8-tetramethyl-10-phenylphenoxaphosphine 10-oxide (II) by pyridine-permanganate oxidation. (I) was synthesized from bis(3,4-dimethylphenyl)ether and phenylphosphonous dichloride by the Friedel-Crafts reaction. The resulting polyimides had reduced viscosities of 0.13–0.84 di/g in cone H₂SO₄ at 30°. They were also soluble in dichloroacetic acid and some of them dissolved in DMA, DMSO. DMF and chloroform. Aromatic phenoxaphosphine-containing polyimides exhibited excellent thermal properties and hardly degraded below about 500°; the aliphatic polyimides decomposed at around 500. The aromatic polyimides had thermal stability similar or superior to aromatic polypyromellitimides and better heat resistance than linear open-chain phosphorus-containing polyimides. These polyimides showed retardance to inflammation.     

Preparation of phosphorus-containing polymers—XX. Synthesis of phenoxaphosphine-containing polyesters

New polyesters containing phenoxaphosphine rings were prepared from 2,8-dichloroformyl-10-phenylphenoxaphosphine 10-oxide (I) and bisphenols by interfacial polycondensation. The investigations of polymerization conditions using (I) and bisphenol A showed that addition of quarternary ammonium salts was effective in the preparation of polyesters. The highest viscosities were obtained when tetrabutylammonium chloride was used as accelerator. Some of the resulting polyesters had reduced viscosities of 0.85–1.92 dl/g in DMA of m-cresol and they dissolved in chloroform, m-cresol and nitrobenzene. These polymers melted in the range of 288–355′, hardly degraded below 400′ and were self-extinguishing. They appeared to have better thermal stability than linear open-chain phosphorus-containing polyesters.     

Flame retardant epoxy polymers based on all phosphorus-containing components

A phosphorus-containing epoxy resin, bis(3-t-butyl-4-glycidyloxyphenyl-2,4-di-t-butylphenyl)resorcinol diphosphate, was synthesized and subsequently cured with non-phosphorus containing amines, and/or novel phosphorus-containing aromatic or polyoxyalkylene amines. Chemical structures of these materials were characterized with FTIR, NMR, elemental analysis, and amine titration. The introduction of soft -P-O- linkage, polyoxyalkyene, or hard aromatic group into the backbones of the synthesized phosphorus-containing amines provides epoxy polymers with high phosphorus contents and tailored flexibility. Thermal analysis of differential scanning calorimeter and thermal gravimetric analysis (TGA) reveals that these resulted epoxy polymers possess moderate T_gs and thermal stability. Furthermore, high char yields in TGA analysis and high limited oxygen index values indicate that these phosphorus-containing epoxy polymers possess excellent flame retardant properties.     

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.     

Solvent Molecule Controlled Zinc(II) Metal‐Organic Frameworks with Different Topology

Two zinc(II) coordination polymers, namely [Zn₂(bptc)(DMF)₂(H₂O)]_n ( 1 ) and [Zn(bptc)_0.5(DMA)]_n ( 2 ) (H₄bptc = biphenyl‐3,3′,5,5′‐tetracarboxylic acid, DMF = N,N′‐dimethylformamide, DMA = N,N′‐dimethylacetamide), were obtained under solvothermal conditions by varying the reaction solvents. Single crystal X‐ray diffraction analyses revealed that compound 1 features a 3D PtS type framework based on dinuclear [Zn₂O(COO)₂] subunits and compound 2 features a 3D lvt type framework based on paddle‐wheel shaped [Zn₂(COO)₄] subunits. Moreover, the luminescent and thermal stabilities of these two compounds were investigated.     

Synthesis of phosphorus-containing polyurethanes without use of isocyanates

Phosphorus-containing polyurethanes were synthesized by reacting phosphonic acid diesters (RO)₂P(O)X (X = H, CH₃, Ph) with hydroxycarbamates. These phosphorus-containing polyurethanes were characterized by a combination of molecular-weight determination (GPC) and NMR spectroscopy. The thermal stability of the polymers was evaluated by a combination of TGA and DTA techniques. These polymers are readily soluble in highly polar solvents like DMF and DMSO. The phosphorus-containing polyurethanes are water soluble. © 1996 John Wiley & Sons, Inc.     

Synthesis,characterization and thermal degradation kinetics of ferrocene‐containing aramids

Low‐temperature solution‐phase polycondensation of 1,1′‐ferrocenedicarboxylic acid chloride with different aromatic diamines was carried out in tetrahydrofuran in the presence of triethylamine to afford ferrocene‐containing aramids. The products were characterized by their solubilities, inherent viscosities, elemental analysis, FTIR spectroscopy, differential scanning calorimetry and thermogravimetry. All of them were insoluble in common solvents tested, except aramid‐IV (derived from 1,8‐naphthalene diamine), which was slightly soluble in N,N′‐dimethylacetamide, N,N′‐dimethylformamide, dimethylsulfoxide and formic acid. However, all were miscible with concentrated H₂SO₄, forming red‐coloured solutions. These all show a reduction in their solution viscosities at ambient conditions in concentrated H₂SO₄ which may be attributed to their non‐Newtonian behaviour. The glass transition temperature for each aramid was quite high, and stable up to 390 °C. The integral procedural decomposition temperatures for the products were calculated using Doyle's method and were found to be intermediate to that of Nylon 66 (419 °C) and Teflon (555 °C), and the activation energy for decomposition of each product was calculated by the Horowitz and Metzger method. Copyright © 2005 John Wiley & Sons, Ltd.     

X-ray diffraction study of Al-Si melts

New layered metal-organic coordination polymers [Zn₃(bpdc)₃(DMA)₂]·3DMA (1) (H₂bpdc = 4,4′-biphenyldicaboxylic acid, DMA = N,N′-dimethylacetamide) and [Zn₃(bdc)₃(im)₂]·1.5H₂O (2) (H₂bdc = terephtalic acid, im = imidazole) are synthesized and characterized by X-ray crystallography.     

Solvent-free synthesis of three layered manganese sulfate-oxalates with different pore apertures

Three manganese sulfate-oxalates, namely, H₂pip·Mn₂(SO₄)₂(ox)(H₂O)₂·2H₂O (1), H₃ipa⋅Mn₂(SO₄)(ox)_2.5·H₂O (2), and H₃dpta⋅Mn₂(SO₄)₂(ox)_1.5(H₂O)₃ (3), were prepared under solvent-free conditions, where pip = piperazine, ox = oxalate, ipa = 3,3′-iminobis(N,N-dimethylpropylamine), and dpta = dipropylenetriamine. These compounds have different layered structures intercalated with organic cations. Their pore apertures range from small 8-membered ring (8 MR) to large 12 MR and extra-large 20 MR. The temperature dependence of the magnetic susceptibility of these compounds were also investigated.     

Onium salts of sulfur-containing oxyanions resulting from reaction of sulfur(IV) oxide with aqueous solutions of 1,2-diamines and morpholine

Reaction products have been isolated from SO₂–L–H₂O–О2 systems (L = ethylenediamine, N,N,N′,N′-tetramethylethylenediamine, piperazine, and morpholine) as onium salts [H₃NCH₂CH₂NH₃]SO₄, [(CH₃)₂NHCH₂CH₂NH(CH₃)₂]SO₄, [(CH₃)₂NHCH₂CH₂NH(CH₃)₂]S₂O₆ ? H₂O, [C₄H₈N₂H₄]SO₃ ? H₂O, [C₄H₈N₂H₄]S₂O₆, [C₄H₈N₂H₄]SO₄ ? H₂O, [O(C₂H₄)₂NH₂]₂SO₄ ? H₂O. The prepared compounds have been characterized by X-ray diffraction analysis, X-ray powder diffraction, IR and mass spectroscopy.     

Novel aromatic polyimides derived from benzofuro[2,3-b]benzofuran-2,3,8,9-tetracarboxylic dianhydride (BBTDA)

Benzofuro[2,3-b]benzofuran-2,3,8,9-tetracarboxylic dianhydride (BBTDA) is introduced as a monomer for the synthesis of a series of novel polyimides with enhanced high thermal stability. Polyimides derived from BBTDA and aromatic diamines showed high glass transition (T_g>296 °C) and degradation (T₅>455 °C) temperatures, and were soluble in organic solvents (i.e. N-methyl pyrrolidone (NMP), N,N^′-dimethylformamide (DMF), N,N^′-dimethylacetamide (DMAc)). The polymerization yielded high-molecular-weight polyimides with inherent viscosities ranging from 1.75 to 2.14 dl/g. The polymers were characterized by IR and elemental analysis.     

Synthesis and characterization of thermally stable poly-N, N′-arylenebismaleimide

Three N,N′-arylenebismaleimides, viz. N,N′-m-phenylenebismaleimide, N,N′-p-phenylenebismaleimide and N,N′-benzidinebismaleimide, were prepared and polymerized in toluene using benzoyl peroxide (BPO) as initiator. The polymers obtained were characterized on the basis of elemental analysis and IR spectra. The polymers are insoluble in common organic solvents. The thermal behaviour of these polymers was studied by DTA and TG methods and the kinetic parameters order of reaction and activation energy were estimated.     

Synthesis and properties of alkylruthenium complexes bearing primary and secondary amine ligands

A series of 18-electron alkylruthenium complexes, RuR[κ²(N,N′)-(S,S)-R′SO₂NCHPhCHPhNH₂](η⁶-arene) (Ph = C₆H₅, R′ = p-CH₃C₆H₄ and CH₃), bearing a N-sulfonylated diamine ligand was synthesized from the reaction of RuCl[κ²(N, N′)-(S,S)-R′SO₂NCHPhCHPhNH₂](η⁶-arene) with alkylzinc reagents, in which transmetalation proceeded smoothly to give the desired alkyl complexes in good yield and selectivity. Although the isolable amine Ru complexes bearing functionalized alkyl ligands were thermally stable, the simple methyl and ethyl Ru complexes underwent intramolecular deprotonation from NH protons to give the amido Ru complexes with release of the alkanes. The reactivity of the alkyl Ru complexes is highly affected by the structures of the arene ligands.     

Relation of the chemical structure of polycyanurates to thermal and mechanical properties

Forty polycyanurates were prepared by the interfacial polycondensation of 2-substituted 4,6-dichloro-s-triazines with various aromatic diols. Nitrobenzene was used as a solvent, aqueous sodium hydroxide as an acid acceptor, and a cationic emulsifier as an accelerator. The rate of reaction was largely increased by ultrasonic irradiation. The polymer yield was in the range 57–91%, and the reduced viscosity was 0.41–3.5. The polymers were soluble in chloroform, nitrobenzene, and o-dichlorobenzene but insoluble in common organic solvents such as alcohol, acetone, and hydrocarbons. A clear film was obtained from the chloroform-soluble polymers after evaporation of the solvent. The softening temperature and the thermal stability of each polycyanurate was significantly related to the substituent on the s-triazine nucleus as well as to the diol component in the molecular chain. Polymers of favorable properties were derived from 2-substituted 4,6-dichloro-s-triazines with R = ? C₆H₅, ? N(C₆H₅)₂, ? N(C₆H₁₁)₂, ? N(C₆H₅)(SO₂C₆H₄CH₃), or carbazyl and aromatic diols such as 4,4′-dihydroxybenzophenone, Bisphenol A, or phenolphthalein. These polymers showed tensile strength of 500–670 kg/cm², elongation at break of 2.9–6.0%, and a minor weight loss at 300–350°C.     

Thermal degradation kinetics of thermoresponsive poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) copolymers prepared via RAFT polymerization

Reversible addition-fragmentation chain transfer polymerization at 70 °C in N,N-dimethylformamide was used to prepare poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) copolymers in various compositions to afford well-defined polymers with pre-determined molecular weight, narrow molecular weight distribution, and precise chain end structure. The copolymer compositions were determined by ¹H NMR spectroscopy. The reactivity ratios of N-isopropylacrylamide (NIPAM) and N,N-dimethylacrylamide (DMA) were calculated as r _NIPAM = 0.838 and r _DMA = 1.105, respectively, by the extended Kelen–Tüdös method at high conversions. The lower critical solution temperature of PNIPAM can be altered by changing the DMA content in the copolymer chain. Differential scanning calorimetry and thermogravimetric analysis at different heating rates were carried out on these copolymers to understand the nature of thermal degradation and to determine its kinetics. Different kinetic models were applied to estimate various parameters like the activation energy, the order, and the frequency factor. These studies are important to understand the solid state polymer degradation of N-alkyl substituted polymers, which show great potential in the preparation of miscible polymer blends due to their ability to interact through hydrogen bonding.     

Accelerated methods of synthesis of phosphorus-containing dendrimers

In order to shorten the long and tedious synthesis of dendrimers, several improvements have been proposed. This paper is a review of the improved methods recently published concerning the synthesis of phosphorus-containing dendrimers. It describes first the synthesis of hyperbranched polymers and their comparison with real dendrimers obtained from the same monomer. Then, the influence of the modification of the core of dendrimers is shown. In a third part, the use of dendrons is illustrated by several examples; they allow for instance to built a generation 8 directly from a generation 3 dendrimer. The last part describes the use of branched monomers of types AB₂ and CD₂, in which A reacts only with D and B reacts only with C. These reactions do not need any protecting groups, and the only by-products are H₂O and N₂. Using these monomers, the 4th generation is obtained in only four steps, instead of 8 for classical methods. This method has been improved by using more branched monomers AB₅ and CD₅, built from the cyclotriphosphazene. In this case, a dendrimer having 750 end groups is obtained in only three steps. The A (NH₂), B (PPh₂), C (N₃) and D (CHO) functions are identical in all cases, and they allow a real “Lego” chemistry, as shown by the synthesis of CA₂ and DB₂ monomers, also used for the accelerated synthesis of dendrimers.