Synthesis and characterization of novel soluble poly(ether ketone sulfone)s with pendant polychloro groups

A novel monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175–180°C for 10 h and confirmed by FTIR, MS, and elemental analysis. Five new polychloro substituted poly(aryl ether ketone sulfone)s (PEKSs) with inherent viscosities of 0.68–0.75 dL/g have been prepared from 4,4′‐diphenoxydiphenylsulfone, 4,4′‐bis(2‐methylphenoxy) diphenylsulfone, 4,4′‐bis(3‐methylph‐enoxy)diphenylsulfone, 4,4′‐bis(2,6‐dimethylphenoxy)diphenylsulfone, and 4,4′‐bis(1‐naphthoxy)‐diphenylsulfone with TCTPC by electrophilic Friedel‐Crafts acylation in the presence of DMF with anhydrous AlCl₃ as a catalyst in 1,2‐dichloroethane, respectively. These polymers having weight–average molecular weight in the range of 76,600–83,900 are all amorphous and show high glass transition temperatures ranging from 213 to 250°C, the 5% weight loss temperature over 450°C, high char yields of 60–67% at 700°C in nitrogen and good solubility in CHCl₃ and polar solvents such as DMF, DMSO, and NMP at room temperature. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 85.1–90.8 MPa, Young's moduli of 2.52–3.24 GPa, and elongations at break of 21.2–27.2%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis,characterization, and properties of new siloxane grafted copolyimides

Three new siloxane containing grafted copolyimides have been prepared by one‐pot solution imidization technique. The polymers are made by the reaction of 4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) with commercially available diamine 4,4′‐oxydianiline (ODA) with variation of silicon containing diamine, namely 3,5‐diaminobenzoate terminated polydimethylsiloxane (DBPDMS), as a comonomer to 10, 20, and 30 wt %. The films of the polymers were prepared by casting the polymer solution in dichloromethane. The polymers have been well‐characterized by GPC, IR, and NMR techniques. Thermal stabilities and decomposition behavior of the copolyimides were studied by DSC and TGA. The water contact angle values of the films indicate hydrophobic nature of the polymers. Thermal, flame retardant, mechanical, and surface properties of these polymers have been compared with the homopolyimide and with polyimides where polysiloxane is incorporated in the main chain. DSC revealed melting of the grafted siloxane chain at sub‐ambient temperature and a glass transition corresponding to the main polymer chain above 200°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of poly(aryl ether sulfone ether ketone ketone) (PESEKK)

4,4′‐bis(Phenoxy)diphenyl sulfone (DPODPS) was synthesized by reaction of phenol with bis(4‐chlorophenyl) sulfone in tetramethylene sulfone in the presence of NaOH. Two poly(aryl ether sulfone ether ketone ketone)s (PESKKs) with high molecular weight were prepared by low temperature solution polycondensation of DPODPS and terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC), respectively, in 1,2‐dichloroethane and in the presence of aluminum chloride (AlCl₃) and N‐methylpyrrolidone (NMP). The resulting polymers were characterized by various analytical techniques, such as FT‐IR, ¹H‐NMR, DSC, TG, and WAXD. The results show that the T_g and T_d of PESEKKs are much higher, but its T_m is lower than those of PEKK. The other results indicate that PESEKKs exhibit excellent thermostabilities at 300 ± 10°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 489–493, 2005     

Comparative study of silicon‐containing polyimides from different oxydianilines

Silicon‐containing polyimides were synthesized by solution polycondensation of bis(3,4‐dicarboxyphenyl)dimethylsilane dianhydride with 3,4‐oxydianiline and 4,4′‐oxydianiline, respectively. All the poly(amic acid) films could be obtained by solution‐casting from N,N‐dimethylacetamide solutions and thermally converted into transparent and tough polyimide films. The physical properties of thin films of those polyimides were compared by DSC, TGA, UV–visible spectroscopy, and dynamic mechanical analysis. The polyimide from bis(3,4‐dicarboxyphenyl)dimethylsilane dianhydride and 3,4‐oxydianiline exhibited superior energy‐damping characteristic, mechanical properties, and optical transparency, whereas that from bis(3,4‐dicarboxyphenyl)dimethylsilane dianhydride and 4,4′‐oxydianiline possessed higher glass‐transition temperature and thermal stability. Because of the unsymmetric structure of the polyimide from bis(3,4‐dicarboxyphenyl)dimethylsilane dianhydride and 3,4‐oxydianiline, its increasing rate of linear coefficient of thermal expansion with temperature was quicker than that of the polyimide from bis(3,4‐dicarboxyphenyl)dimethylsilane dianhydride and 4,4′‐oxydianiline. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2363–2367, 2004     

Synthesis and characterization of polyimide/hexagonal boron nitride composite

Polyimide (PI)/hexagonal boron nitride (h‐BN) composites were produced via the thermal imidization procedure from solution mixtures of a polyamicacid, which is prepared from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 3,3′‐diaminodiphenyl sulfone (DADPS) in N‐methyl‐2‐pyrrolidone (NMP), and alkoxysilane functionalized h‐BN. The structure, thermostability, thermal behavior, and surface properties of the resulting materials were characterized by means of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM). The thermal characteristics of PI/h‐BN films were better than the pure PIs. The physical and mechanical properties of the films were evaluated by various techniques such as contact angle, chemical resistance, and tensile tests. The flame retardancy of the composite materials was also examined by the limiting oxygen index (LOI). The experiments showed that the LOI values of PIs increased from 32 to 43 for the materials containing hexagonal boron nitride. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

New poly(amide imide imide)s based on tetraimide dicarboxylic acid condensed from 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride,m‐aminobenzoic acid,and 4,4″‐oxydianiline and various aromatic diamines

A series of new, organosoluble, and light‐colored poly(amide imide imide)s were synthesized from tetraimide dicarboxylic acid ( I ) and various aromatic diamines by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. I was prepared by the azeotropic condensation of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, m‐aminobenzoic acid, and 4,4′‐oxydianiline at a 2/2/1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP)/toluene. The thin films cast from N,N‐dimethylacetamide (DMAc) had cutoff wavelengths shorter than 400 nm (365–394 nm) and color coordinate b* values between 13.10 and 36.07; these polymers were lighter in color than the analogous poly(amide imide)s and isomeric polymers. All of the polymers were readily soluble in a variety of organic solvents, including NMP, DMAc, N,N‐dimethylformamide, dimethyl sulfoxide, and even less polar dioxane and tetrahydrofuran. The cast films exhibited tensile strengths of 90–104 MPa, elongations at break of 7–22%, and initial moduli of 1.9–2.4 GPa. The glass‐transition temperatures of the polymers were recorded at 274–319°C. They had 10% weight losses at temperatures beyond 520°C and left more than a 50% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 669–679, 2003     

Thermal degradation of polymers. Part XVIII. The synthesis and characterization of quinazolone pre-polymers

A series of quinazolone pre-polymers have been prepared from 4,4′-diaminodiphenyl-3,3′-dicarboxylic acid and aromatic diacetamido compounds by melt polycondensation. The pre-polymers have been characterized by combustion analysis, viscometry, vapor pressure osmometry, and thermal analytical methods (TG, DTA, and DSC). Structures have been elucidated by spectroscopic methods (IR and NMR). The thermal cyclization of these pre-polymers to the partial ladder polyquinazolone has been studied and optimized using IR, DSC/DTA, TG, and evolved gas analysis. The cyclization behavior of these systems has been resolved in terms of concurrent dehydration and decarboxylation.     

Dynamics of solvent diffusion in an aromatic polyimide

Diffusion behaviors of two polyimides (PIs) synthesized from 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 4,4′-oxydianiline (ODA), and 4,4′-diaminodiphenylsulfone (DDS) were investigated by the gravimetric method. The weight uptake of penetrants (solvents) was nearly proportional to the exposure time in solvent. This phenomenon was considered as the Case II diffusion (non-Fickian) mechanism. Two PI films had an affinity to N-methyl-2-pyrrolidinone (NMP) rather than to dimethylsulfoxide (DMSO). The solubility parameter differences between two polyimides and NMP are less than 5, whereas that between polyimides and DMSO are greater than 5, as calculated by Hoy's group contribution method. The solvent uptake of anisotropic films contributed to an increase in the thickness. The swollen amount of anisotropic films increased with the swelling temperature but tended to decrease with the imide content and the thickness of the anisotropic films. Isotropic films of two PIs did not swell in both NMP and DMSO. © 1994 John Wiley & Sons, Inc.     

Synthesis of novel poly(amide‐imide)s containing trimellitylimido‐DL/L‐alanine moieties via direct polycondensation

N‐Trimellitylimido‐DL and L ‐alanine ( 3 ) were prepared from the reaction of trimellitic anhydride ( 1 ) with DL and L ‐alanine ( 2 ) in N,N‐dimethyl formamide (DMF) solution at refluxing temperature. The direct polycondensation reaction of the monomers imide‐diacid ( 3 ) with 4,4′‐diaminodiphenylsulfone ( 4a ), 4,4′‐diaminodiphenylmethane ( 4b ), 1,4‐phenylenediamine ( 4c ), 1,3‐phenylenediamine ( 4d ), 2,4‐diaminotoluene ( 4e ), and 4,4′‐diaminodiphenylether ( 4f ) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone (NMP), pyridine, and calcium chloride. The resulting poly(amide‐imide)s PAIs, with inherent viscosities 0.32–0.66 dL/g, were obtained in high yield. All of the above‐mentioned compounds were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAI s are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1312–1318, 2001     

Catalytic decomposition of ethanol on ­V2O5/AlPO4 catalysts

Different ratios of vanadium pentoxide supported on aluminum phosphate (1–30 mol%) have been prepared by an impregnation method. The original and calcined samples were characterized by TG, DTG, DSC, X‐ray diffraction, IR spectra, N₂ adsorption and electrical conductivity measurements. The catalytic decomposition of ethanol has been carried out at 210 °C in a flow system at 1 atm using air as a carrier gas. The results indicate that the catalysts calcined at 400 °C were active and selective towards ethene formation whereas the samples calcined at 600 °C showed a drastic reduction in both activity and selectivity. © 2000 Society of Chemical Industry     

Synthesis and properties of elastic polyurethane‐imide

A new synthesis route for elastic polyurethane‐imides (EPUIs) has been established by a method involving the use of urea. Various EPUIs were synthesized from polyurethane‐urea, which was prepared from 4,4′‐diphenylmethane diisocyanate (MDI), polyoxytetramethylene glycol (PTMG) and 4,4′‐diphenylmethanediamine (MDA), and pyromellitic dianhydride in N‐methyl‐2‐pyrrolidone (NMP). Flexible films were cast from these solutions that had different inherent viscosities. Imidization of the EPUI films was completed at 200°C for 4 h in vacuo. The EPUIs were determined by FTIR, ¹H NMR, and ¹³C NMR spectra. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and properties of some novel,soluble and light‐coloured,aromatic poly(amide–imide) copolymers

A new type of tetraimide‐dicarboxylic acid (I) was synthesized starting from the ring‐opening addition of m‐aminobenzoic acid (m‐ABA), 4,4′‐oxydiphthalic anhydride (ODPA) and 4,4′‐methylenedianiline (MDA) at a 2:2:1 molar ratio in N‐methyl‐2‐pyrrolidone (NMP), followed by cyclodehydration to the diacid I. A series of soluble and light‐coloured poly(amide–imide–imide)s (III_a–j) was prepared by triphenyl phosphite‐activated polycondensation from the tetraimide‐diacid I with various aromatic diamines (II_a–j). All films cast from DMAc had cutoff wavelengths shorter than 400 nm (376–393 nm) and had b* values between 20.46 and 40.67; these polymers were much lighter in colour than those of the corresponding trimellitimide series. All polymers were readily soluble in a variety of organic solvents such as NMP, N,N‐dimethylacetamide, dimethyl sulfoxide, and even in the less polar m‐cresol and pyridine. Compared with those of corresponding ODPA–MDA polyimide, the solubilities of poly(amide–imide–imide)s III_a–j were greatly improved. Polymers III_a–j afforded tough, transparent, and flexible films, which had tensile strengths ranging from 82 to 105 MPa, elongations at break from 8 to 14%, and initial moduli from 2.0 to 2.2 GPa. The glass transition temperature of polymers were recorded at 255–288 °C. They had 10% weight loss at a temperature above 540 °C and left more than 60% residue even at 800 °C in nitrogen. © 2002 Society of Chemical Industry     

Studies on thermal and morphological behavior of siliconized epoxy bismaleimide matrices

Novel bismaleimide‐modified siliconized epoxy intercrosslinked network systems were developed. Siliconized epoxy systems containing 5, 10, and 15% siloxane units were prepared using epoxy resin and hydroxyl‐terminated polydimethylsiloxane (HTPDMS) with γ‐aminopropyltriethoxysilane (γ‐APS) as a compatibilizer and dibutyltindilaurate as a catalyst. The siliconized epoxy systems were further modified with 5, 10, and 15% (wt %) of bismaleimide [(N,N′‐bismaleimido‐4,4′‐diphenylmethane) (BMI)] and cured by diaminodiphenylmethane (DDM). Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and heat‐distortion temperature measurement of the matrix samples were carried out to assess their thermal behavior. DSC thermograms of the BMI‐modified epoxy systems show unimodel reaction exotherms. The glass transition temperature (T_g) of the cured BMI‐modified epoxy and siliconized epoxy systems increases with increasing BMI content. Thermogravimetric analysis and heat‐distortion temperature measurements indicate that the thermal degradation temperature and heat‐distortion temperature of the BMI‐modified epoxy and siliconized epoxy systems increase with increasing BMI content. The morphology of the BMI‐modified siliconized epoxy systems was also studied by scanning electron microscopy (SEM). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2330–2346, 2001     

Preparation and characterization of sepiolite‐poly(ethyl methacrylate) and poly(2‐hydroxyethyl methacrylate) nanocomposites

Poly(ethyl methacrylate) (PEMA) and poly(2‐hydroxyethyl methacrylate) (PHEMA) nanocomposites with sepiolite in pristine and silylated form were prepared using the solution intercalation method and characterized by the measurements of XRD, TEM, FTIR‐ATR, TG/DTG, and DSC. The TEM analysis indicated that the volume fraction of fibers in sepiolite decreased and the fiber bundles dispersed in PEMA and PHEMA at a nanometer scale. These results regarding TEM micrographs were in agreement with the data obtained by XRD. The increase in thermal stability of nanocomposites of PEMA is higher than that of PHEMA according to the data obtained from TG curves. The DTG analysis revealed that sepiolite/modified sepiolite caused some changes, as confirmed by FTIR in the thermal degradation mechanism of the polymers. T_g temperatures of PEMA and PHEMA usually increased upon the addition of sepiolite/modified sepiolite. In addition, modification of sepiolite with 3‐APTS had a slight influence on thermal properties of the nanocomposites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Low‐κ nanocomposite films based on polyimides with grafted polyhedral oligomeric silsesquioxane

Nanocomposites of polyimides (PI) with covalently grafted polyhedral oligomeric silsesquioxane (R₇R′Si₈O₁₂ or POSS) units were prepared by thermally‐initiated free‐radical graft polymerization of methacrylcyclopentyl‐POSS (MA‐POSS) with the ozone‐pretreated poly[N,N′‐(1,4‐phenylene)‐3,3′,4,4′‐benzophenonetetra‐carboxylic amic acid] (PAA), followed by thermal imidization. The chemical composition and structure of the PI with grafted methacrylcyclopentyl‐POSS side chains (PI‐g‐PMA‐POSS copolymers) were characterized by nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). The POSS molecules in each grafted PMA side chain of the amorphous PI films retained the nanoporous crystalline structure, and formed an aggregate of crystallites. The PI‐g‐PMA‐POSS nanocomposite films had both lower and tunable dielectric constants, in comparison with that of the pristine PI films. Dielectric constants (κ's) of about 3.0–2.2 were obtained. The present approach offers a convenient way for preparing low‐κ materials based on existing PI's. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Preparation of polyamides containing para-linked dimethylbiphenylene moieties

A series of wholly aromatic polyamides containing 3,3′-dimethylbiphenyl-4,4′-dicarboxylic acid (P-DMBA) and 3,4′-dimethylbiphenyl-4,3′-dicarboxylic acid (Q-DMBA) was prepared by the direct polycondensation method using triphenylphosphite and pyridine. Most of the polymers are readily soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone (NMP), N,N′-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), pyridine (py), and m-cresol and could be cast into tough and flexible films. The solubilities of copolyamides containing P-DMBA and Q-DMBA as acid components were remarkably improved. These were characterized by inherent viscosity, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical spectrometry (DMS) measurements. The glass transition temperatures of these polymers were in the range of 200–300°C and the 5% weight loss temperatures were 430–470°C. Films prepared by casting from polymer solutions exhibited good tensile properties. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:847–853, 1998     

Synthesis and properties of new aromatic polyimides based on 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride

New polyimides with enhanced thermal stability and high solubility were synthesized in common organic solvents from a new dianhydride, 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride (DBBTDA). DBBTDA was used as monomer to synthesize polyimides by using various aromatic diamines. The polymers were characterized by IR and NMR spectroscopy and elemental analysis. These polyimides had good inherent viscosities in N‐methyl‐2‐pyrrolidinone (NMP) and also high solubility and excellent thermo‐oxidative stability, with 5 % weight loss in the range 433 to 597 °C. Copyright © 2004 Society of Chemical Industry     

Synthesis and thermal,mechanical and gas permeation properties of aromatic polyimides containing different linkage groups

Two series of aromatic polyimides containing various linkage groups based on 2,7‐bis(4‐aminophenoxy)naphthalene or 3,3′‐dimethyl‐4,4′‐diaminodiphenylmethane and different aromatic dianhydrides, namely 4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthalic anhydride), 4,4′‐(hexafluoroisopropylidene)bis(phthalic anhydride), 3,3′,4,4′ benzophenonetetracarboxylic dianhydride, 9,9‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]fluorene dianhydride and 4,4′‐(4,4′‐hexafluoroisopropylidenediphenoxy)bis(phthalic anhydride), were synthesized and compared with regard to their thermal, mechanical and gas permeation properties. All these polymers showed high thermal stability with initial decomposition temperature in the range 475–525 °C and glass transition temperature between 208 and 286 °C. Also, the polymer films presented good mechanical characteristics with tensile strength in the range 60–91 MPa and storage modulus in the range 1700–2375 MPa. The macromolecular chain packing induced by dianhydride and diamine segments was investigated by examining gas permeation through the polymer films. The relationships between chain mobility and interchain distance and the obtained values for gas permeability are discussed. © 2014 Society of Chemical Industry     

Thermal and crystalline properties of water‐borne polyurethanes based on IPDI,DMPA, and PEBA/HNA

A series of water‐borne polyurethanes (WPUs) with different soft segments, various COOH contents, and various hard segment contents were prepared through a prepolymerization process. Thermal and crystalline properties of their films were studied by the measurement of differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and thermogravimetry (TG), respectively. Two T_g areas in DSC of WPUs with polyethylene‐butylene adipate glycol (PEBA) as the soft segment were found; an endothermic peak at ～ 33°C was also found with polyhexane neopentyl adipate glycol (HNA) as the soft segment. The DSC of WPUs with the mixture of PEBA/HNA as soft segment was investigated to show similarity to those from HNA, but with a relatively smaller endothermic peak at ～ 34°C. Three sharp diffraction peaks at 2θ = 20.50°, 21.72°, and 24.54° in XRD of water‐borne PUs from HNA were found to indicate the crystallization of soft segments, which was disrupted by the addition of polyacrylate (PA), as evidenced by the amorphous shoulder at ～ 2θ = 20°. TG analysis and differential thermogravimetric (DTG) analysis were measured to indicate that the films lost weight in two stages, and the decomposition temperatures of the films depended on the COOH content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1936–1941, 2007     

Novel acetylene‐terminated polyimide oligomers with excellent processability and high toughness of films

A series of acetylene‐terminated imide oligomers based on 2,3,3′,4′‐Diphenyl ether tetracarboxylic acid dianhydride (a‐ODPA), 3,4′‐Oxydianiline (3,4′‐ODA), and 3‐Ethynylaniline (3‐EA) with different molecular weights were synthesized by using acetic anhydride and triethylamine as dehydrating agent. Their main structure was confirmed by Fourier transform infrared spectroscopy (FT‐IR). Thermal curing processing was characterized by FT‐IR and differential scanning calorimetry (DSC). All the uncured imide oligomers showed excellent solubility (more than 30 wt %) in organic solvent such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP). These imide oligomers also possessed a very low viscosity, thus provided better processing window. These oligomers were formulated into thermosetting films by thermal crosslinking of the ethynyl groups. The properties of cured films were evaluated by dynamic mechanical thermal analysis (DMA), thermogravimetric analysis (TGA), and tensile measurement. The glass transition temperature (T_g) and elongation at break of the cured films were found to be almost >260°C and >9.2%, respectively. The cured films in air resulted in higher thermal stability than those under N₂ atmosphere. Experimental results suggested that the introduction of asymmetric and flexible ether‐hinge with 3‐EA in polyimide oligomers can improve the processability of the imide oligomers and the toughness for a cured sample without sacrificing their thermal‐oxidative stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42537.