Thermal and Mechanical Properties of Poly(arylene ether ketone)s Based on 5‐tert‐Butyl‐1,3‐bis(4‐fluorobenzoyl)benzene

An aromatic bishalide, 5‐tert‐butyl‐1,3‐bis(4‐fluorobenzoyl)benzene ( 2 ) was synthesized in high yield and purity by the reaction of 5‐tert‐butylisophthaloyl chloride ( 1 ) and fluorobenzene and polymerized by nucleophilic substitution reaction with commercially available aromatic bisphenols to prepare a series of high molecular weight poly(arylene ether ketone)s containing pendant tertiary butyl groups. The effect of molecular structure on the physical, thermal, mechanical and adhesion properties of the polymers was investigated.     

Layered zinc 4-phosphonoisophthalates pillared by flexible bis(imidazole) Co-ligands

This paper reports two zinc phosphonates based on 4-phosphonoisophthalic acid (4-piH₄) and bis(imidazole) co-ligands, namely, [Zn₂(4-pi)(1,2-bix)] (1) and [Zn₂(4-pi)(1,3-bix)] (2) (1,2-bix = 1,2-bis(imidazol-1-ylmethyl)benzene, 1,3-bix = 1,3-bis(imidazol-1-ylmethyl)benzene). Both show layer structures in which the inorganic tetranuclear cores of Zn₄P₂O₆ are connected by 4-pi⁴⁻ligands. The 1,2-bix or 1,3-bix ligand binds to the Zn atoms within the tetranuclear unit or between the neighboring tetranuclear units in a cis-coordination mode, and fill in the interlayer spaces in both cases. The luminescent properties are investigated.     

Phase-transfer catalyzed synthesis of poly(etherketone)s

Summary A novel synthetic method for the preparation of high molecular weight aromatic poly- (etherketone)s is described. N-Alkyl(4-N,N-dialkylamino)pyridinium chlorides 1, 2 and 3 were used as phase-transfer catalysts in polycondensation reactions of 1,4-bis(4-chlorobenzoyl)benzene (4) with aromatic diphenols via nucleophilic displacement. The polycondensations were significantly promoted and, moreover, the results achieved in terms of molecular weight and reaction time were comparable to polymerizations conducted with 1,4-bis(4-fluorobenzoyl)benzene (5), which is a considerably more reactive monomer.     

Synthesis and characterization of new poly(ether–ester–imide)s as a generation of soluble and thermally stable polymers

A new-type of dicarboxylic acid 6 was synthesized from the reaction of 1,4-bis[4-aminophenoxy]butane 4 with trimellitic anhydride 5 in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature. 1,4-Bis[4-nitrophenoxy]butane 3 was prepared by reaction of 4-nitrophenol 1 with 1,4-dibromo butane 2 in N,N-dimethylformamide (DMF) solution. Then dinitro 3 was reduced to 1,4-bis[4-aminophenoxy]butane 4 by using 10% Pd–C, ethanol, and hydrazine monohydrate. So six new thermally stable and organosoluble poly(ether–ester–imide)s (PEEIs) 8a–f with good inherent viscosities were synthesized by the direct polycondensation reaction of new 1,4-bis[4-(trimellitimido)phenoxy]butane 6 with several aromatic diols 7a–f through direct polycondensation using tosyl chloride (TsCl)/pyridine (Py)/DMF system as condensing agent. The resulted polymers were fully characterized by means of FTIR and ¹H NMR spectroscopy, elemental analyses, inherent viscosity, solubility tests, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and derivative of thermogravimetric (DTG).     

Living tandem free radical polymerization of a liquid crystalline monomer

Treatment of 1-β-(4′-acetylphenyl)vinyl-3-vinyl-1,1,3,3-tetramethyldisiloxane (I) (an AB₂ monomer) with dihydridocarbonyltris(triphenylphosphine)ruthenium (Ru) leads to a hyperbranched material, poly[1-β-(4′-acetylphenyl)vinyl-3-vinyl-1,1,3,3-tetramethyldisiloxane] (II). I has been prepared by a Pd catalyzed Heck reaction between 4-bromo-acetophenone and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane. The structure of the soluble hyperbranched material (II) has been determined by ¹H, ¹³C and ²⁹Si NMR, as well as by IR and UV spectroscopy. It has also been characterized by GPC, TGA, DSC and elemental analysis. Polymerization occurs by Ru catalyzed addition of the aromatic C−H bonds which are ortho to the activating acetyl group of I across the C−C double bond of the terminal Si-vinyl group in an anti-Markovnikov manner. Received: 8 September 1997/Revised version: 19 October 1997/Accepted: 20 November 1997     

High thermal stable thermoplastic-thermosetting polyimide film by use of asymmetric dianhydride (a-BPDA)

In order to obtain thermoplastic (before curing) and thermosetting (after curing) polyimides with high T_g for adhesive film, we prepared novel polyimides having phenylethynyl group in the side chain (44% of concentration of curing group) from asymmetric 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA), 3,4′-oxydianiline (3,4′-ODA) or 1,3-bis(4-aminophenoxy)benzene (1,3,4-APB) or 1,3-bis(3-aminophenoxy)benzene (1,3,3-APB), and 2,4-diamino-1-(4-phenylethynylphenoxy)benzene (mPDAp). Among three kinds of polymer, uncured polyimide of a-BPDA/1,3,4-APB; mPDAp had rather high T_g (265 °C, DMA) and thermoplasticity (E′ drop>10³ at T_g). After curing reaction of phenylethynyl group, the T_g of the polyimide was increased dramatically (364 °C, DMA). The polyimide derived from 1,3,4-APB having less concentration of curing group (20%) was also prepared to improve further film flexibility and toughness.     

Four New Ag(I) Coordination Polymers: Synthesis, Crystal Structures and Thermal Stability

Four silver(I) coordination polymers of composition [Ag₆(bptp)₃(OOCCF₂CF₂COO)₃]_∞ (1), [Ag₅(bptp)₂(CF₃SO₃)₅(CH₃COCH₃)₂]_∞ (2), [Ag(bmtm)(C₁₀H₇SO₃)]_∞ (3), and [Ag₁₀(bpte)₄(NO₃)₁₀]_∞ (4) (bmtm = bis(methylthio)methane, bpte = 1,2-bis(phenylthio)ethane, bptp = 1,3-bis(phenylthio)propane) have been synthesized and structurally characterized. The 2D-coordination networks of both 1 and 2 consist of two meshed networks, (Ag-anion)_∞ and (Ag-ligand)_∞, which share their silver atoms. The 1D-coordination polymers of 3 are associated through weak van der Waals interactions into 2D network while polymer 4 forms a tubular structure. Relatively short Ag···Ag interactions are found in both 1 and 3. The stoichiometries of the obtained polymers were found to be independent of the starting materials metal-to-ligand ratio except for coordination polymer 4. Thermogravimetric analyses of 1 and 2 revealed that they decompose in a single step to metallic silver while 3 and 4 showed a two-step weight loss.     

Synthesis and antimicrobial evaluation of some pyrazolo-thiazolyl alkoxy-1H-isoindole-1, 3(2H)-dione derivatives

1,3-Thiazolidine-2,4-dione 2 has been synthesized by the cyclisation reaction of thiourea and chloroacetic acid in the presence of ethanol. The reaction of compound 2 with substituted aromatic aldehyde afforded the corresponding derivatives of substituted 5-benzylidene-1,3-thiazolidinone-2,4-dione 3a–d, which upon reflux with ω-bromoalkoxyphthalimide gave 2-{[-5-(substituted benzylidine)-2,4-dioxo-1,3-thiazolidine-3-yl]alkoxy} -1H-isoindole-1,3(2H)-dione 4a–i. Further, compounds 4a–i were treated with phenyl hydrazine and 2,4 dinitro phenyl hydrazine in the DMF to yield the title compound 2-[5-oxo-2,3-substituted diphenyl-2H-pyrazolo[3,4-d][1,3]thiazol-6(5H)-yl)alkoxy]-1H-isoindole-1,3(2H)-dione 5a–r. Structures of newly synthesized compounds were established based on elemental analysis, IR, ¹H NMR and mass spectral data. Synthesized compounds have been assayed for their antibacterial activities against B. subtilis, K. pneumoniae, P. aeruginosa and S. aureus and antifungal activities against A. fumigatus and C. albicans.     

Synthesis and curing behavior of a benzoxazine based on phenolphthalein and its high performance polymer

A pure benzoxazine synthesized from phenolphthalein through Mannich reaction, 3,3′-bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazinyl)-1(3H)-isobenzofuranone (Boz-BP), was characterized by FTIR and ¹H NMR. Its curing behavior was different with that of 2,2′-bis(4-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (Boz-BA) because Boz-BP possesses highly steric and inactivated phenol rings. During curing period, the reactivity of ortho position of phenolic hydroxyl group was retarded and the addition of -CH₂- group generated in ring-opening reaction preferred to taking place on para position of aniline ring, which is beneficial for better thermal properties. Furthermore, additional hydrogen bonding would be formed between carbonyl groups on phthalide structure and hydroxyl groups in Boz-BP based polymer (P(Boz-BP)). Compared with the analogous polymer from Boz-BA (P(Boz-BA)), P(Boz-BP) displayed higher glass transition temperature, better thermal stability, better dimensional stability and flame-retardant properties.     

Metal-Containing Polymers Synthesized via Acyclic Diene Metathesis (ADMET) Polymerization Using Electrochemically Reduced Tungsten-Based Catalyst: Polycarbogermanes

Various germanium-containing dienes, bis(4-pentenyl)diethylgermanium (1), bis(4-pentenyl)dimethylgermanium (2) and bis(3-butenyl)diethylgermanium (3), were synthesized and polymerized using an electrochemically reduced tungsten-based catalyst system via acyclic diene metathesis (ADMET) polymerization. All polymer structures were characterized by ¹H- and ¹³C-NMR spectroscopy. These results indicate the retention of the double bonds in the polymer structure with high trans content (57–70%) as expected from a step condensation reaction. These polymers have low molecular weight (M _W) that range from 7400 to 19,100. The thermal stability of polymers was evaluated by thermogravimetric analysis. The glass transition temperatures of the polymer of monomer 1, 2 and 3 were −24, −9 and −47°C, respectively. Synthesis, characterization and the general limitations of ADMET polymers obtained by this catalyst are discussed. An erratum to this article can be found at     

Synthesis of Conjugated Polymers Containing Phosphole with the 5-Member Fused Carbocycle

Summary Novel conjugated polymers 9a–c possessing the phosphole ring with the 5-member fused carbocycle were synthesized by palladium catalyzed coupling reaction of 1-phenyl-2,5-bis(p-bromophenyl)phosphole 7 with diethynylarenes 8a–c. The obtained polymers 9a–c had the regio-regulated 2,5-substituted phosphole ring in the polymer main chain, and were characterized by ¹H, ¹³C, ³¹P NMR, and FTIR. The ³¹P NMR spectra revealed that the extension of π-conjugation changed the phosphole ring angles. The optical properties of polymers 9a–c were independent of the size of the fused carbocycle.     

Direct Polyamidation of N,N’-(4,4’-Hexafluoroisopropy-lidendiphthaloyl)-bis-L-isoleucine with Different Aromatic Diamines via Vilsmeier Adduct Derived from Tosyl Chloride and N,N-Dimethylformamide

Summary Various approaches have been carried out in the synthesis of poly(amide-imide)s. A well-developed solution polycondensation method has been used to prepare such copolymers either from a dianhydride containing a preformed amide group with a diamine or from a dicarboxylic acid containing a preformed imide ring with a diamine. Direct polycondensations of carboxylic acids and aromatic diamines can be a more useful technique for synthesis of poly(amide-imide)s PAIs. In this work, direct polymerization reaction of N,N’-(4,4’-hexafluoroisopropylidendiphthaloyl)-bis-L-isoleucine with several aromatic diamines such as 4,4’-diaminodiphenylsulphone (4a), 4,4’-diaminodiphenylmethane (4b), 4,4’-diaminodiphenylether (4c), 1,4-phenylenediamine (4d), 4,4’-diaminobiphenyl (4e), 1,3-phenylenediamine (4f), 2,4-diaminotoluene (4g), was performed in the presence of tosyl chloride (TsCl)/dimethylformamide (DMF)/pyridine (Py) as a condensing agent. The resulting PAIs were obtained in high yield and inherent viscosity. Some structural characterization and physical properties of these polymers have been studied and will be reported.     

Synthesis and characterization of heterocyclic,and optically active poly(amide-imide)s by phosphorylation polycondensation

Summary N,N′-Pyromelliticdiimido-di-L-methionine (1), N,N′-Pyromelliticdiimido-di-L-alanine (2), N,N′-Pyromelliticdiimido-di-L-phenylalanine (3) , and N,N′-Pyromelliticdiimido-di-L-leucine (4) were prepared from the reaction of Pyromellitic dianhydride with corresponding L-amino acids in a mixture of glacial acetic acid and pyridine solution (3/2 ratio) under refluxing conditions. The phosphorylation polycondensation of the corresponding diimide-diacid monomers with 4-phenyl-2,6-bis(4-aminophenyl) pyridine (6) or 4-(p-methylthiophenyl)-2,6-bis(4-aminophenyl) pyridine (8) were carried out in N-methyl-2-pyrolidone (NMP). The resulting poly (amide-imide)s were obtained in quantitative yields, showed admirable inherent viscosities (0.20-0.97 dl g^-1), were soluble in polar aprotic solvents, showed good thermal stability and high optical purity. The synthetic compounds were characterized by IR, MS, ¹H NMR and ¹³C NMR spectroscopy, elemental analysis and specific rotation.     

Specific Ortho-bromination. I. Preparation of ortho-bromo substituted benzenes

A process¹ for the synthesis of ortho-bromo aromatic compounds was studied. The process is based on the blocking and shielding effect of a tertiary butyl group which is introduced on to the aromatic ring prior to bromination. The removal of the tertiary butyl group, after bromination, is accomplished by transferring it to another aromatic nucleus via an aluminium trichloride catalysed transalkylation reaction. Synthesis of six different compounds are described and a recycle process is illustrated.     

Conformational studies of polycyanurates: a study of internal stress versus molecular structure

A new parameter set (RDA-DR2.21_Inv) is shown to reproduce both the geometries and the physical and mechanical properties of three polycyanurates based on 2,2-bis(4-cyanatophenyl)propane, 1,1-bis(4-cyanatophenyl)ethane and 1,3-bis(4-cyanatophenyl-1-(1-methylethylidene))benzene. The results show a trend of internal stress within the molecule caused by varying backbone structure. The simulated Young's modulus of elasticity decreases in the order: 1,1-bis(4-cyanatophenyl)ethane>2,2-bis(4-cyanatophenyl)propane>1,3-bis(4-cyanatophenyl-1-(1-methylethylidene))benzene (from 31.11 to 14.33 GPa). Molecular dynamics simulations, carried out on 1,1-bis(4-cyanatophenyl)ethane and 1,3-bis(4-cyanatophenyl-1-(1-methylethylidene))benzene, reproduce the empirical glass transition temperatures (T_g) of the polycyanurates well, although the calculated T_g values are slightly overestimated when compared with the empirical data, presumably due to the ‘perfect’ nature of the simulated network.     

Studies on the Antioxidants XIX: Photooxidation products of tertiary butyl hydroquinone (TBHQ) (bdII)

A series of studies have been made with a view to pursuing the fate of antioxidant molecules during the antioxidation processes. In this study following that reported in the preceding paper, tertiary butyl hydroquinone (TBHQ) in benzene solution was irradiated with ultraviolet rays and the chemical structure and antioxidative activities of the resulting photooxidation products were examined. They were identified as the following three compounds: 2-(2-[3′-tert-butyl-4′-hydroxyphenoxy] - 2-methyl-1 -propyl)hydroquinone, which was a dimer of the intermediate generated by photorearrangement of the tert-butyl group and the substrate TBHQ, 2-(2-hydroxy-2-methyl-l-propyl)hydroquinone, which was formed by interaction of the rearranged tert-butyl group with water, and2- tert- butyl- 4- ethoxy-phenol, which was formed from a secondary decomposition of the dimer. All of the resulting oxidation products showed antioxidative activity on methyl oleate, soybean oil and lard in the stability test by the active oxygen method (AOM).     

Synthesis of a novel dialkylaryl disulfonate gemini surfactant

A single-step route was developed for synthesizing a dialkylaryl disulfonate gemini surfactant using α-olefin sulfonic acid. The new process is very simple and effective, requiring neither the conventional alkylation unit nor strong acid catalysts. The resulting dialkylaryl disulfonica acids differ from existing products by having the sulfonyl group attached to the alkyl chain rather than the aromatic ring. To optimize the reaction conditions, a reliable double-wavelength spectrophotometric method was studied to analyze the conversion of an aromatic (benzene or methylnaphthalene) based on the difference in ultraviolet absorption spectra between the aromatic and the corresponding dialkylaryl disulfonate. The experiments suggested that the reaction time and temperature affected the conversion and optimal condition; a reaction time of 5 h (or 4 h) and a reaction temperature of 150°C were obtained and applied to the products ditetradecylmethylnaphthalene disulfonate (DTMNDS) and ditetradecylbenzene disulfonate (DTBDS). In addition, the surface-active properties of DTMNDS and DTBDS were investigated in detail. Their critical micelle concentrations were 2×10⁻⁵ and 1.7×10⁻⁴ mol·L⁻¹, respectively. The data showed that the two new dialkylaryl disulfonate gemini surfactants had higher surface activities than the conventional dodecylbenzene sulfonate, suggesting they will have broad utility in industrial and household applications in the future.     

Syntheses and Crystal Structures of Zinc(II) and Nickel(II) Coordination Polymers Based on Diphenic Acid and 1,2-Bis(4-pyridyl)ethane Coligands

Two new metal coordination polymers [Zn₂(dpa)₂(bpa)] (1) and [Ni₄(dpa)₄(bpa)₃] (2) [H₂dpa = 2,4′-biphenyldicarboxylic acid and bpa = 1,2-bis(4-pyridyl)ethane] have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray diffraction analysis reveals that complex 1 shows a 2D (4,4) topological net and complex 2 features a 3D network with (4.6²)₂(4².6¹⁰.8³) topology. Fluorescent study of complex 1 shows that it has an emission at 414 nm in the solid state at room temperature.     

Synthesis of Organosoluble and Optically Active Poly(ester-imide)s by Direct Polycondensation with Tosyl Chloride in Pyridine and Dimethylformamide

Summary 4,4′-Oxydiphthalic anhydride (1) was reacted with L-methionine (2) in acetic acid and the resulting N,N′-(4,4′-oxydiphthaloyl)-bis-L-methionine diacid (4) was obtained in high yield. The direct polycondensation reaction of this diacid with several aromatic diols such as bisphenol A (5a), phenolphthalein (5b), 1,4-dihydroxyanthraquinone (5c), 4,4′-dihydroxydiphenyl sulfide (5d), 2,6-dihydroxytoluene (5e), 4,4′-dihydroxydiphenyl sulfone (5f) and 2,4′-dihydroxyacetophenone (5g) was carried out in a system of tosyl chloride (TsCl), pyridine (Py) and N,N-dimethylformamide (DMF). The reactions with TsCl were significantly promoted by controlling alcoholysis with diols in the presence of the catalytic amounts of DMF to give a series of optically active poly(ester-imide)s (PEI)s with good yield and moderate inherent viscosity ranging 0.21–0.71 dL/g. The polycondensation reactions were significantly affected by the amounts of DMF, molar concentration of monomers, TsCl and pyridine, aging time, addition time of diols, temperature and the reaction time. All of the above polymers were fully characterized by ¹H-NMR, FT-IR, elemental analysis and specific rotation. Some structural characterization and physical properties of these new optically active PEIs are reported.     

Amine-terminated aromatic and semi-aromatic hyperbranched polyamides: synthesis and characterization

A facile synthetic approach to aromatic and semiaromatic amine-terminated hyperbranched polyamides via direct polymerization of triamine (B₃) with different diacid chlorides (A₂) was explored. An aromatic triamine, 1,3,5-tris(4′-aminophenylcarbamoyl)benzene (TAPCB), was synthesized and monomers were characterized by elemental analysis, FTIR, ¹H and ¹³C NMR spectroscopy. Finally, the polycondensation reaction of TAPCB with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), sebacoyl chloride (SC) and adipoyl chloride (AC) resulted in the preparation of four hyperbranched polyamides i.e., HBPA 1, 2, 3 and 4, respectively. FTIR and ¹H NMR analyses confirmed the structures of the ensuing polymers and DB was found between 0.51–0.55. These thermally stable amorphous HBPAs were soluble in polar aprotic solvents at room temperature having glass transition temperatures (T_g) between 138–198 °C. Inherent viscosities (η_inh) and weight average molecular weights (M_w) were in the range of 0.27–0.35 dL/g and 1.3 × 10⁴–2.7 × 10⁴, respectively. Future prospects are envisaged.