Synthesis and properties of poly(arylene ether)s based on 3‐pentadecyl 4,4'‐biphenol

A new biphenol, 3‐pentadecyl 4,4′‐biphenol, was synthesized starting from 3‐pentadecylphenol and was polycondensed with 4,4′‐difluorobenzophenone, 1,3‐bis(4‐fluorobenzoyl)benzene and bis(4‐fluorophenyl)sulfone to obtain poly(arylene ether)s with biphenylene linkages in the backbone and pendent pentadecyl chains. Inherent viscosities and number‐average molecular weights (M_n) of the poly(arylene ether)s were in the range 0.50 ? 0.81 dL g^?1 and 2.2 × 10⁴ ? 8.3 × 10⁴, respectively. Detailed NMR spectroscopic studies of the poly(arylene ether)s indicated the presence of constitutional isomerism which existed because of the non‐symmetrical structure of 3‐pentadecyl 4,4′‐biphenol. The poly(arylene ether)s readily dissolved in common organic solvents such as dichloromethane, chloroform and tetrahydrofuran and could be cast into tough, transparent and flexible films from their chloroform solutions. The poly(arylene ether)s exhibited T_g values in the range 35–60 °C which are lower than that of reference poly(arylene ether)s without pentadecyl chains. The 10% decomposition temperatures (T₁₀) of the poly(arylene ether)s were in the range 410–455 °C indicating their good thermal stability. A gas permeation study of poly(ether sulfone) containing pendent pentadecyl chains revealed a moderate increase in permeability for helium, hydrogen and oxygen. However, there was a large increase in permeability for carbon dioxide which could be attributed to the internal plasticization effect of pendent pentadecyl chains. © 2016 Society of Chemical Industry     

New poly(1,3,4‐oxadiazole)s bearing pentadecyl side chains: Synthesis and characterization

The 4‐[4′‐(Hydrazinocarbonyl)phenoxy]‐2‐pentadecylbenzohydrazide was polycondensed with aromatic diacid chlorides viz., terephthalic acid chloride (TPC), isophthalic acid chloride (IPC), and a mixture of TPC : IPC (50 : 50 mol %) to obtain polyhydrazides which on subsequent cyclodehydration reaction in the presence of phosphoryl chloride yielded new poly(1,3,4‐oxadiazole)s bearing flexibilizing ether linkages and pentadecyl side chains. Inherent viscosities of polyhydrazides and poly(1,3,4‐oxadiazole)s were in the range 0.53–0.66 dL g^?1 and 0.49–0.53 dL g^?1, respectively, indicating formation of medium to reasonably high molecular weight polymers. The number average molecular weights (M_n) and polydispersities (M_w/M_n) of poly(1,3,4‐oxadiazole)s were in the range 14,660–21,370 and 2.2–2.5, respectively. Polyhydrazides and poly(1,3,4‐oxadiazole)s were soluble in polar aprotic solvents such as N,N‐dimethylacetamide, 1‐methyl‐2‐pyrrolidinone, and N,N‐dimethylformamide. Furthermore, poly(1,3,4‐oxadiazole)s were also found to be soluble in solvents such as chloroform, dichloromethane, tetrahydrofuran, pyridine, and m‐cresol. Transparent, flexible, and tough films of polyhydrazides and poly(1,3,4‐oxadiazole)s could be cast from N,N‐dimethylacetamide and chloroform solutions, respectively. Both polyhydrazides and poly(1,3,4‐oxadiazole)s were amorphous in nature and formation of layered structure was observed due to packing of pentadecyl chains. A decrease in glass transition temperature was observed both in polyhydrazides (143–166°C) and poly(1,3,4‐oxadiazole)s (90–102°C) which could be ascribed to “internal plasticization” effect of pentadecyl chains. The T₁₀ values, obtained from TG curves, for poly(1,3,4‐oxadiazole)s were in the range of 433–449°C indicating their good thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124:1281–1289, 2012     

Synthesis and characterization of new aromatic polyesters containing pendent naphthyl units

Two bisphenols, viz., 4,4′‐[1‐(2‐naphthalenyl)ethylidene]bisphenol and 4,4′‐[1‐(2‐naphthalenyl) ethylidene]bis‐3‐methylphenol were prepared by condensation of commercially available 2‐acetonaphthanone with phenol and o‐cresol, respectively. A series of new aromatic polyesters containing pendent naphthyl units was synthesized by phase‐transfer‐catalyzed interfacial polycondensation of these bisphenols with isophthaloyl chloride, terephthaloyl chloride, and a mixture of isophthaloyl chloride/terephthaloyl chloride (50 : 50 mol %). Inherent viscosities of polyesters were in the range 0.83–1.76 dL g⁻¹, while number average molecular weights (M_n) were in the range 61,000–235,000 g mol⁻¹. Polyesters were readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, m‐cresol, pyridine, N,N‐dimethylformamide, N,N‐dimethylacetamide, and 1‐methyl‐2‐pyrrolidinone at room temperature. Tough, transparent, and flexible films were cast from a solution of polyesters in chloroform. X‐Ray diffraction measurements displayed a broad halo at 2θ ≅ 19° indicating the amorphous nature of polyesters. Glass transition temperatures of polyesters were in the range 209–259°C. The temperature at 10% weight loss (T₁₀), determined by TGA in nitrogen atmosphere, of polyesters was in the range 435–500°C indicating their good thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of polyesters based on 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane

Aromatic polyesters are of considerable interest because of their excellent mechanical properties, chemical resistance and thermal stability. However, most aromatic polyesters are difficult to process due to their high glass transition temperatures coupled with their insolubility in common organic solvents. The present article describes a series of organosoluble polyesters and copolyesters based on 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane. A series of new aromatic polyesters containing pendant pentadecyl chains was synthesized by interfacial polycondensation of 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane with terephthalic acid chloride (TPC), isophthalic acid chloride (IPC) and a mixture of TPC and IPC. A series of copolyesters was synthesized from 4,4′‐isopropylidenediphenol with TPC by incorporating 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane as a comonomer. Inherent viscosities of the polyesters and copolyesters were in the range 0.72–1.65 dL g^?1 and number‐average molecular weights were in the range 18 170–87 220. The polyesters and copolyesters containing pendant pentadecyl chains dissolved readily in organic solvents such as chloroform, dichloromethane, pyridine and m‐cresol and could be cast into transparent, flexible and apparently tough films. Wide‐angle X‐ray diffraction data revealed the amorphous nature of the polyesters and copolyesters. The formation of loosely developed layered structure was observed due to the packing of pendant pentadecyl chains. The temperature at 10% weight loss, determined using thermogravimetric analysis in nitrogen atmosphere, of the polyesters and copolyesters containing pendant pentadecyl chains was in the range 400–460 °C. The polyesters and copolyesters exhibited glass transition temperatures in the range 63–82 °C and 177–183 °C, respectively. Copyright © 2010 Society of Chemical Industry     

Synthesis and characterization of organo‐soluble poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains

Poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains were synthesized by polycondensation of each of the two bisphenol monomers viz, 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane and 1,1‐bis(4‐hydroxyphenyl)‐3‐pentadecyl cyclohexane with activated aromatic dihalides namely, 4,4′‐difluorobenzophenone, and 1,3‐bis(4‐fluorobenzoyl)benzene in a solvent mixture of N,N‐dimethylacetamide and toluene, in the presence of anhydrous potassium carbonate. Polymers were isolated as white fibrous materials with inherent viscosities and number average molecular weights in the range 0.70–1.27 dL g^?1 and 76,620–1,36,720, respectively. Poly(ether ether ketone)s and poly(ether ether ketone ketone)s were found to be soluble at room temperature in organic solvents such as chloroform, dichloromethane, tetrahydrofuran, and pyridine and could be cast into tough, transparent, and flexible films from their solutions in chloroform. Wide angle X‐ray diffraction patterns exhibited a broad halo at around 2θ = ～ 19° indicating that the polymers containing pentadecyl chains were amorphous in nature. In the small‐angle region, diffuse reflections of a typically layered structures resulting from the packing of pentadecyl side chains were observed. The temperature at 10% weight loss, obtained from TG curves, for poly(ether ether ketone)s and poly(ether ether ketone ketone)s were in the range 416–459°C, indicating their good thermal stability. A substantial drop in glass transition temperatures (68–78°C) was observed for poly(ether ether ketone)s and poly(ether ether ketone ketone)s due to “internal plasticization” effect of flexible pendant pentadecyl chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of fluorine and nitrile containing polyimides

A series of polyimides were synthesized from new diamine, Bis [4,4′‐amino‐5,5′ trifluoromethyl phenoxy‐(hexafluoro isopropylidine) phenoxy phenyl] benzonitrile [BATFB] and various aromatic tetracarboxylic anhydrides by thermal and chemical imidization routes. The BATFB was synthesized in two steps by nucleophilic displacement reaction of 2,6‐dichloro benzonitrile, 4,4′‐(hexafluoro isopropylidine) diphenol and 2‐amino‐5‐fluoro benzotrifluoride in the presence of anhydrous potassium carbonate in N,N′‐dimethyl acetamide (DMAc) and the structure was confirmed by FTIR spectroscopy and CHNSO analyzer. The polymers were characterized by FTIR spectroscopy and thermal analysis were performed by differential scanning calorimetry and thermogravimetric analysis methods. The prepared polyimides had glass transition temperatures between 230 and 290°C and their 10% weight loss were recorded in the range 550–590°C in N₂ atmosphere. Majority of polymers are found to be soluble in most of the organic solvents such as DMSO, DMF, DMAc, m‐cresol, and THF even at room temperature and few becomes soluble on heating. The prepared polyimides showed water uptake values 0.34–0.54 wt % at room temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3455–3461, 2006     

Synthesis and properties of novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) and poly(ether amide ether amide ether ketone ketone)

New monomers, 4,4′‐bis(4‐phenoxybenzoyl)diphenyl (BPOBDP) and N,N′‐bis(4‐phenoxybenzoyl)?4,4′‐diaminodiphenyl ether (BPBDAE), were conveniently synthesized via simple synthetic procedures from readily available materials. Novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) (PEKDKEKK) and poly(ether amide ether amide ether ketone ketone) (PEAEAEKK) were synthesized by electrophilic Friedel‐Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBDP and BPBDAE, over a wide range of BPOBDP/BPBDAE molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The copolymers obtained were characterized by different physico‐chemical techniques. The copolymers with 10–40 mol% BPBDAE are semicrystalline and had remarkably increased T_gs over commercially available PEEK and PEKK due to the incorporation of amide and diphenyl linkages in the main chains. The copolymers IV and V with 30–40 mol% BPBDAE had not only high T_gs of 185–188°C, but also moderate T_ms of 326–330°C, having good potential for the melt processing. The copolymers IV and V had tensile strengths of 101.7–102.3 MPa, Young's moduli of 2.19–2.42 GPa, and elongations at break of 13.2–16.6% and exhibited high thermal stability and excellent resistance to organic solvents. POLYM. ENG. SCI., 54:1757–1764, 2014. © 2013 Society of Plastics Engineers     

Soluble and crosslinkable poly(phthalazinone ether ketone)s with pendent terminal ethynyl groups: synthesis,characterization and click modification

New poly(phthalazinone ether ketone)s (PPEKs) with pendent terminal ethynyl groups were synthesized by the aromatic nucleophilic substitution (S_NAr) polycondensation reaction of a new bisphenol monomer, 2‐(3‐ethynylphenyl)hydroquinone, with 4‐(4′‐hydroxyphenyl)phthalazin‐1(2H)‐one and 4,4′‐bis(4‐fluorophenyl) ketone, followed by click modification reaction with 1‐azidopyrene. Fourier transform infrared and NMR spectral data of the model compound indicated that the terminal ethynyl groups were stable in S_NAr reaction conditions, thus allowing the synthesis of the desired polymers. The PPEKs obtained with glass transition temperature (T_g) in the range 152–245 °C were amorphous, characterized by wide‐angle X‐ray diffraction, and dissolved in organic solvent to cast into transparent and flexible films. Differential scanning calorimetry results indicated that the curing reaction of the terminal ethynyl groups of the copolymers took place upon heating to 250 °C. The T_g of cured PPEKs was increased to about 260 °C. They also exhibited excellent thermal stability with 5% weight loss temperatures ranging from 448 to 527 °C in various atmospheres. The PPEKs with pendent terminal ethynyl groups were subsequently functionalized with pyrene through click reaction. A dilute chloroform solution displayed a red‐shifted emission profile. © 2014 Society of Chemical Industry     

Preparation and properties of novel soluble aromatic polyetherimides from 1,1′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane dianhydride and aromatic diamines

New aromatic polyetherimides containing the 1,1′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane dianhydride unit were prepared by a conventional two-step method from 1,1′-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane dianhydride and several diamines. This procedure yielded high molecular weight polyetherimides with inherent viscosities of 0.22–1.29 dL/g. Most of the corresponding polyetherimides were soluble in organic solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N,N-dimethylacetamide, and methylene chloride under ambient temperature. The glass transition temperatures (T_g) of these polymers were in the range of 207–264°C and the temperatures of 10% weight loss were over 520°C at a heating rate 20°C/min in nitrogen. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of novel polyaspartimides derived from 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl and various diamines

A novel bismaleimide, 2,2′‐dimethyl‐4,4′‐bis(4‐maleimidophenoxy)biphenyl, containing noncoplanar 2,2′‐dimethylbiphenylene and flexible ether units in the polymer backbone was synthesized from 2,2′‐dimethyl‐4,4′‐bis(4‐aminophenoxy)biphenyl with maleic anhydride. The bismaleimide was reacted with 11 diamines using m‐cresol as a solvent and glacial acetic acid as a catalyst to produce novel polyaspartimides. Polymers were identified by elemental analysis and infrared spectroscopy, and characterized by solubility test, X‐ray diffraction, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis). The inherent viscosities of the polymers varied from 0.22 to 0.48 dL g⁻¹ in concentration of 1.0 g dL⁻¹ of N,N‐dimethylformamide. All polymers are soluble in N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethylsulfoxide, pyridine, m‐cresol, and tetrahydrofuran. The polymers, except PASI‐4, had moderate glass transition temperature in the range of 188°–226°C and good thermo‐oxidative stability, losing 10% mass in the range of 375°–426°C in air and 357°–415°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 279–286, 1999     

Synthesis and characterization of new soluble poly(ester‐imide)s containing noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit

A new diimide–diacid chloride (3) containing a noncoplanar 2,2′‐dimethyl‐4,4′‐biphenylene unit was synthesized by treating 2,2′‐dimethyl‐4,4′‐diamino‐biphenylene with trimellitic anhydride followed by refluxing with thionyl chloride. Various new poly(ester‐imide)s were prepared from 3 with different bisphenols by solution polycondensation in nitrobenzene using pyridine as hydrogen chloride quencher at 170°C. Inherent viscosities of the poly(ester‐imide)s were found to range between 0.31 and 0.35 dL g^?1. All of the poly(ester‐imide)s, except the one containing pendent adamantyl group 5e, exhibited excellent solubility in the following solvents: N,N‐dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidinone, m‐cresol, o‐chlorophenol, and chloroform. The polymers showed glass‐transition temperatures between 166 and 226°C. The 10% weight loss temperatures of the poly(ester‐imide)s, measured by TGA, were found to be in the range between 415 and 456°C in nitrogen. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2486–2493, 2004     

Synthesis and properties of fluoro‐polyetherimides

A series of amorphous fluoro‐polyetherimides based on 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di‐ether‐containing diamines 4,4′‐bis(3‐aminophenoxy)diphenyl sulfone (m‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone (p‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl propane (BPADE) were synthesized. These melt processable polyetherimide polymers from p‐SED and BPADE showed excellent electrical properties. The dielectric constants, 2.74 and 2.65 at 10 MHz respectively, are lower than commercially available polyetherimide ULTEM® 1000, and polyimide Kapton® H films. In addition, we found that trifluoromethyl groups‐containing polyimides not only show extraordinary electrical properties, but they also exhibit excellent long‐term thermo‐oxidative stability and reduced water absorption relative to non‐fluorinated polyimides. The weight retention of these fluoro‐polyetherimides at 315°C for 300 h in air varies from 93% to 98%. Whereas, their moisture absorption at 100 RH at 50°C was in the range of 0.3% to 1.05%, which is much lower than those of Ultem 1000 and Kapton H. In the case of fluoro‐polyetherimides from p‐SED and m‐SED (para and meta isomers) diamines with ‘ether’ and sulfonyl (‐SO₂‐) spacer groups, the d‐spacing and T_g values decreased from 4.72Å to 4.56Å and 293°C to 244°C respectively. Similarly, the transparency of these polymer films (in the range of 80% to 90%) at 500 nm solar wavelength was higher than Ultem 1000 and Kapton H.     

Synthesis of soluble and thermally stable polyimides from 3,5‐diamino‐N‐(4‐(8‐quinolinoxy) phenyl) aniline and various dianhydrides

Three novel polyimides (PIs) having pendent 4‐(quinolin‐8‐yloxy) aniline group were prepared by polycondensation of a new diamine with commercially available tetracarboxylic dianhydrides, such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs were characterized by FTIR, ¹H NMR, and elemental analysis; they had high yields with inherent viscosities in the range of 0.4–0.5 dl g⁻¹, and exhibited excellent solubility in many organic solvents such as N,N‐dimethyl acetamide, N,N′‐dimethyl formamide, N‐methyl pyrrolidone (NMP), dimethyl sulfoxide, and pyridine. These PIs exhibited glass transition temperatures (T_g) between 250 and 325° C. Their initial decomposition temperatures (T_i) ranged between 270 and 450°C, and 10% weight loss temperature (T₁₀) up to 500°C with 68% char yield at 600°C under nitrogen atmosphere. Transparent and hard polymer films were obtained via casting from their NMP solutions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis,characterization, and gas transport properties of new semifluorinated poly(ether imide)s containing cardo moiety

A series of new semifluorinated poly(ether imide)s (PEI)s was synthesized from a diamine monomer, 9,9‐bis ‐[3‐phenyl‐4‐{2′‐trifluoromethyl‐4′‐(4′′‐aminophenyl)phenoxy} phenyl]fluorene on reaction with three different aromatic dianhydrides namely, 4,4′‐(4,4′‐isopropylidenediphenoxy)bis (phthalic anhydride), 4,4'‐(hexafluoro‐isopropylidene)diphthalic anhydride, and 4,4'‐oxydiphthalic anhydride. The PEIs were well characterized by elemental analysis, spectroscopic, thermal, mechanical, electrical, and optical techniques. The synthesized PEIs showed high glass transition temperature (T_g up to 288 °C) and high thermal stability (T_{d ,10} up to 521 °C under synthetic air), high tensile strength, up to 76 MPa and low dielectric constant (?) (2.35–2.61 at 1 MHz). The membranes prepared from these polymers were studied for their gas permeability for four different gases CO₂, O₂, N₂, and CH₄. The PEI membranes showed high gas permeability (P _CO2 up to 70.3 and P _O2 up to 16.7 Barrer) and high permselectivity (P _CO2/P _CH4 up to 73.6 and P _O2/P _N2 up to 13.4); for the O₂/N₂ gas pair the PEIs surpassed the present upper boundary limit of 2008 drawn by Robeson. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45213.     

Preparation and properties of thermally stable copolyimides based on novel second‐order nonlinear–optical chromophore containing diamines

Thermally stable copolyimides were prepared from two novel second‐order nonlinear optical chromophores containing diamines, 4‐nitro‐4′‐[N‐(4,6‐di‐β‐aminoethylamino)‐1,3,5‐triazin‐2‐yl]aminoazobenzene (M1) and 4‐nitro‐4′‐[N‐(4,6‐di‐4‐aminophenylamino)‐1,3,5‐triazin‐2‐yl]aminoazobenzene (M2); two codiamines, 4,4′‐diamino‐3,3′‐dimethyl diphenylmethane (MMDA) and bis‐(3‐aminopropyl)‐1,1′,3,3′‐tetramethyldisiloxane (SiDA); and 3,3′,4,4′‐diphenyl ether tetracarboxylic acid dianhydride (OPDA). All copolyimides possess high glass transition temperatures (T_g's) between 237 and 271°C. Copolyimides based on M2 do not exhibit an obvious change in T_g as the M2 content is increased, while those based on M1 show a slight decrease in T_g as the M1 content is increased. All copolyimides exhibit high thermal decomposition temperatures. The copolyimides are soluble in aprotic solvents such as NMP, DMAc, DMF, DMSO, and 1,4‐butyrolactone. Some are even soluble in common low boiling point solvents such as THF and chloroform. The refractive index of a copolyimide is increased as the chromophore content is increased, while the birefringence of a copolyimide does not exhibit strong dependence on the chromophore content. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1619–1626, 2000     

Synthesis and properties of novel soluble and high Tg poly(ether imide)s from diamine containing 4,5‐diazafluorene and trifluoromethyl units

The synthesis and properties of soluble, high T_g and transparent aromatic polyimides containing 4,5‐diazafluorene and trifluoromethyl units in the polymer backbone on the basis of a novel diamine monomer, 9,9‐di[4‐(4‐amino‐2‐trifluoromethyl phenoxy)phenylene]‐4,5‐diazafluorene, are described. Incorporation of 4,5‐diazafluorene and trifluoromethyl groups into rigid polyimides improves their solubility and transparency without decreasing their physical properties. All of the thermal imidization polyimides are soluble at room temperature in aprotic and protic polar solvents such as N,N‐dimethylacetamide, N,N′‐dimethylformamide, dimethylsulfoxide, pyridine and m‐cresol and can be solution cast into transparent, flexible and tough films. These films have a UV–visible absorption cutoff wavelength at 386–407 nm and light transparencies of 73%–84% at a wavelength of 550 nm. In addition, the polymers exhibit high thermal stability with a glass transition temperature (T_g) of 305 to 362 °C and 5% weight loss at temperatures ranging from 525 to 543 °C in nitrogen and from 521 to 538 °C in air. The polyimide films possess tensile strengths in the range 79 ? 113 MPa, a tensile modulus of 1.75 – 2.10 GPa and elongations at break of 7% ? 16%. © 2014 Society of Chemical Industry     

Synthesis and characterization of novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide)

A new monomer containing sulfone and imide linkages, bis{4-[4-(p-phenoxyphenylsulfonylphenoxy)benzoyl]-1,2-benzenedioyl}-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPSPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether with 4,4′-diphenoxydiphenyl sulfone. Novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride with a mixture of DPE and BPSPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers with 10–25?mol% BPSPBDADPE are semicrystalline and had increased T _gs over commercially available PEEK and PEKK (70/30) due to the incorporation of sulfone and imide linkages in the main chains. The polymer IV with 25?mol% BPSPBDADPE had not only high T _g of 194?°C but also moderate T _m of 338?°C, having good potential for melt processing and exhibited high thermal stability and good resistance to common organic solvents.     

Preparation and properties of soluble aromatic polyetherimides based on 2,2‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride

Aromatic polyetherimides were synthesized from a fluorine containing aromatic carboxylic acid dianhydride, 2,2‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride (6F‐BABPA) and five typical aromatic diamines including 1,1‐bis(4‐aminophenyl)‐1‐phenyl‐2,2,2‐trifluoroethane (3F‐DAM) by two‐step procedures—amidation to polyamic acids (PAA), followed by thermal imidization of PAA. The chemical and physical properties of the newly prepared polyetherimides (PEI) were compared in terms of their chemical structures, inherent viscosities, mechanical, and thermal properties. All polyetherimides were well soluble in common organic solvents such as N‐methyl‐2‐pyrolidone (NMP), N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), pyridine, and methylene chloride. A PEI prepared from 6F‐BABPA/3F‐DAM was especially easily dissolved in NMP. The glass transition temperature (T_g) range of the obtained PEI was 209–257°C. The dielectric constants and refractive index were 2.8–3.2 and 1.61–1.56, respectively. The polyetherimide, 6F‐BABPA/BAPP, with a low fluorine content (11.4% fluorine content), has 0.99% water absorption, whereas the polyetherimide, 6F‐BABPA/4‐BDAP, having a high fluorine content (26.0% fluorine content) showed 0.35% of water absorption. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 249–257, 2000     

Synthesis of novel optically active poly(ester‐imide)s with benzophenone linkages by microwave‐assisted polycondensation

A new simple and rapid polycondensation reaction of 4,4′‐carbonyl‐bis(phthaloyl‐L ‐alanine)diacid chloride [N,N ′‐(4,4′‐carbonyldiphthaloyl)]bisalanine diacid chloride with several diphenols, such as bisphenol‐A, phenolphthalein, 1,8‐dihydroxyanthraquinone, 4,4′‐dihydroxybiphenyl, 1,5‐dihydroxynaphthalene and hydroquinone, in the presence of a small amount of a polar organic medium such as o‐cresol was performed using a domestic microwave oven. The polycondensation reaction proceeded rapidly and was almost complete within 12 min to give a series of poly(ester‐imide)s with inherent viscosities of about 0.35–0.58 dl g⁻¹. The resulting poly(ester‐imide)s were obtained in high yield and are optically active and thermally stable. All the above compounds have been fully characterized by IR spectroscopy, elemental analysis, inherent viscosity (η_inh), solubility test and specific rotation. Thermal properties of the poly(ester‐imide)s have been investigated using thermal gravimetric analysis (TGA). © 2000 Society of Chemical Industry     

Synthesis and properties of new poly(amide‐imide)s based on 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane and aromatic diamines

Six new poly(amide‐imide)s 8a–f containing trimethylene moiety in the main chain were synthesized by the polycondensation reactions of 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane 6 with six different aromatic diamines 7a–f in a medium constituting N‐methyl‐2‐pyrrolidone, triphenylphosphite, CaCl₂, and pyridine as condensing agents. The polycondensation reaction produced a series of novel poly(amide‐imide)s 8a–f in high yields with inherent viscosities between 0.35 and 0.63 dL/g. The resulting poly(amide‐imide)s were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility tests, and FTIR spectroscopy. 1,3‐Bis[4,4'‐(trimellitimido) phenoxy] propane 6 as a new monomer containing trimethylene moiety was synthesized using a three‐step reaction. At first 1,3‐bis[4,4'‐nitrophenoxy] propane 3 was prepared by the reaction of 4‐nitrophenol 1 with 1,3‐dibromo propane 2 in DMF solution . Then, dinitro 3 was reduced to 1,3‐bis[4,4'‐aminophenoxy] propane 4 by using a solution of sodium sulfite in ethanol. Finally, 1,3‐bis[4,4'‐(trimellitimido) phenoxy] propane 6 was prepared by the reaction of one equivalent diamine 4 with two equivalents of trimellitic anhydride 5 in a mixture of acetic acid‐pyridine (3 : 2). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010