Thermal stability,solubility, and fluorescence property of poly(arylene ether ketone)s bearing <Emphasis Type="Italic">N</Emphasis>-arylenebenzimidazole units

A series of novel random poly(arylene ether ketone)s containing N-arylenebenzimidazolyl groups with precise structures in high yields were synthesized from 2-(2′-hydroxyphenyl) benzimidazole and 4,4′-dihydroxybenzophenone with 4,4′-difluorobenzophenone via nucleophilic substitution polycondensation reaction using sulfolane as a solvent. The reaction was carried out at 210 °C in the presence of anhydrous potassium carbonate. The structures of the resulted polymers were characterized by means of FT-IR, ¹H NMR spectroscopy, and elemental analysis, and the results were largely consistent with the proposed structure. X-ray diffraction studies revealed that the incorporation of N-arylenebenzimidazolyl groups decreased the crystallinity of the resulted polymers. As the benzimidazole unit content in the copolymer increased, the solubility and thermal behavior of the prepared polymers improved. The novel poly(arylene ether ketone)s exhibited glass transition temperatures (T _gs) in the range 188–237°C, and there was a good linearity relationship between T _g values and the content of benzimidazolyl groups. The 5% decomposition temperatures were within the range of 512–539 °C in nitrogen and 496–540 °C in air indicating their good thermal stability. Tensile tests of the films showed that these polymers have desirable mechanical properties. Moreover, the resulting polymers showed good fluorescence properties.     

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

Poly(ether sulfone) and poly(ether sulfone ketone) copolymers (I–V) were synthesized by the nucleophilic substitution reaction of 4,4′-dihydroxy diphenyl sulfone (DHDPS, A) with various mole proportions 4,4′-difluoro benzophenone (DFBP, B) and 4,4′-difluoro diphenyl sulfone (DFDPS, C) using sulfolane as solvent in the presence of anhydrous K₂CO₃. The polymers were characterized by physicochemical and spectroscopic techniques. All polymers were found to be amorphous, and the glass transition temperature (T_g) was found to increase with the sulfonyl content of the polymers. ¹³C-nuclear magnetic resonance (NMR) spectral data was interpreted in terms of the compositional triads, BAB, BAC, CAC, ABA, and ABB, and indicate that transetherification occurs at high concentration of DFBP units in the polymer (IV). The good agreement between the observed and calculated feed ratios validates the triad analysis. Thermal decomposition studies reveal that the thermal stability of the polymers increases with increase in the carbonyl content in the polymer. Activation energies for thermal decomposition were found to be in the range of 160–203 kJ mol⁻¹ with the cleavage of ϕ SO₂ bond being the preponderant mode of decomposition and depended on the block length of the sulfonyl unit. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2113–2121, 1999     

Preparation and properties of bismaleimide resins of aromatic sulfone ether diamine

Aromatic sulfone ether diamine, bis[4-(4-aminophenoxy)phenyl]-sulfone (SED), was prepared by the nucleophilic aromatic substitution of 4,4′-dichlorodiphenylsulphone by p-aminophenolate. The reaction was conducted in the presence of excess potassium carbonate as a weak base, toluene as the dehydrating agent and N-methylpyrrolidone as the dipolar aprotic solvent. SED showed good solubility in common organic solvents, such as dioxan, tetrahydrofuran, butanone and acetone. SED was reacted with maleic anhydride to obtain aromatic sulfone ether bismaleimide, bis[4-(4-maleimidophenoxy)phenyl]-sulfone (SEM). The compounds were characterized by FTIR and ¹H NMR analysis. Furthermore, copolymer resins of SED with 4,4′-bismaleimidodiphenyl methane (BMI) and SEM were prepared. After curing, crosslinked resins with better thermal stability resulted. The temperature at maximum rate of weight loss (T_max) and the heat-resistant temperature index (T_i) in air were found to be 426°C, 208°C and 579°C, 221°C for BMI/SED and SEM/SED resins, respectively. Compared with the corresponding 4,4′-diaminodiphenyl methane (DDM) system, BMI/SED and SEM/SED showed a slight decrease in T_max and T_i SED-modified BMI/amine resin based glass cloth laminates for printed circuit boards showed higher mechanical properties than those of the corresponding unmodified system. With SED instead of the original amine component in 3–5% weight fraction, the tensile strength, flexural strength and impact strength of the laminates increased markedly. Meanwhile, the stripping strength and weld resistance were also improved by the addition of SED.     

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.     

Microwave promoted synthesis and characterization of isomeric poly(ether ether ketone)s

A series of isomeric poly(ether ether ketone)s were synthesized using microwave‐assisted method by nucleophilic substitution reaction of hydroquinone and 4,4′‐biphenol with 4,4′‐difluorobenzophenone (DFBP) or 2,4′‐DFBP in the presence of anhydrous K₂CO₃. The polymers with inherent viscosities in the range of 0.20–0.71 dlg^?1 were obtained in quantitative yields and had excellent thermal stability as shown by the temperature of 5% weight loss in nitrogen above 410°C. X‐ray diffraction patterns confirmed the semicrystalline character of some of the polymers. The results also indicate that the reaction time was shortened remarkably and the reaction temperature could be controlled easily. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers     

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     

Copolymers of poly(arylene sulfide sulfone)/poly(ether sulfone): Synthesis,structure, and rheology properties

In order to overcome the poor flowability of poly(arylene sulfide sulfone) (PASS), we introduced ether bonds into the polymer main chain. A series poly(arylene ether sulfide sulfone) copolymers (PAESS) containing different proportion of ether bonds were synthesized with 4,4′‐dichlorodiphenyl sulfone (DCDPS), sodium sulfide (Na₂S·xH₂O), and 4,4′‐dihydroxydiphenyl ether (DHDPE). The copolymers were characterized by Fourier transform infrared (FTIR), ¹H‐nuclear magnetic resonance (NMR), differential scanning calorimetry, dynamic mechanical analysis (DMA), and rheometer. The results of FTIR and ¹H‐NMR indicate the copolymers are synthesized successfully. PAESS were found to have excellent thermal properties with glass transition temperature (T_g) of 175.7–219.1 °C and 5% weight lost temperature were all above 420 °C. The tensile and DMA test indicates that these resultant copolymers have good mechanical properties with tensile strength of 60 MPa and storage modulus of 1.5 GPa. From the results of rheology properties testing, we found that the melt stability and melt flowability of PASS were improved distinctly from 25,470 Pa s down to 355 Pa s with the incorporation of ether bonds. That will be quite beneficial to the processing of PASS, especially for the thermoforming of precision products. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46534.     

Highly fluorinated poly(ether‐imide)s derived from 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐diaminodiphenyl ether and aromatic dianhydrides

A new diamine, 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐diaminodiphenyl ether (FPAPE) was synthesized through the Suzuki coupling reaction of 2,2′‐diiodo‐4,4′‐dinitrodiphenyl ether with 3,4,5‐trifluorophenylboronic acid to produce 2,2′‐bis(3,4,5‐trifluorophenyl)‐4,4′‐dinitrodiphenyl ether (FPNPE), followed by palladium‐catalyzed hydrazine reduction of FPNPE. FPAPE was then utilized to prepare a novel class of highly fluorinated all‐aromatic poly(ether‐imide)s. The chemical structure of the resulting polymers is well confirmed by infrared and nuclear magnetic resonance spectroscopic methods. Limiting viscosity numbers of the polymer solutions at 25 °C were measured through the extrapolation of the concentrations used to zero. M_n and M_w of these polymers were about 10 000 and 25 000 g mol^?1, respectively. The polymers showed a good film‐forming ability, and some characteristics of their thin films including color and flexibility were investigated qualitatively. An excellent solubility in polar organic solvents was observed. X‐ray diffraction measurements showed that the fluoro‐containing polymers have a nearly amorphous nature. The resulting polymers had T_g values higher than 340 °C and were thermally stable, with 10% weight loss temperatures being recorded above 550 °C. Based on the results obtained, FPAPE can be considered as a promising design to prepare the related high performance polymeric materials. Copyright © 2011 Society of Chemical Industry     

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     

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

Poly(aryl ether ketone)s (PAEKs) are a class of high‐performance engineering thermoplastics known for their excellent combination of chemical, physical and mechanical properties, and the synthesis of semicrystalline PAEKs with increased glass transition temperatures (T_g) is of much interest. In the work reported, a series of novel copolymers of poly(ether ketone ketone) (PEKK) and poly(ether amide ether amide ether ketone ketone) were synthesized by electrophilic solution polycondensation of terephthaloyl chloride with a mixture of diphenyl ether and N,N′‐bis(4‐phenoxybenzoyl)‐4,4′‐diaminodiphenyl ether (BPBDAE) under mild conditions. The copolymers obtained were characterized using various physicochemical techniques. The copolymers with 10–35 mol% BPBDAE are semicrystalline and have markedly increased T_g over commercially available poly(ether ether ketone) and PEKK due to the incorporation of amide linkages in the main chain. The copolymers with 30–35 mol% BPBDAE not only have high T_g of 178–186 °C, but also moderate melting temperatures of 335–339 °C, having good potential for melt processing. The copolymers with 30–35 mol% BPBDAE have tensile strengths of 102.4–103.8 MPa, Young's moduli of 2.33–2.45 GPa and elongations at break of 11.7–13.2%, and exhibit high thermal stability and good resistance to organic solvents. Copyright © 2010 Society of Chemical Industry     

Synthesis of poly(arylene ether nitrile ketone)s bearing phthalazinone moiety and their properties

Copoly(arylene ether nitrile ketone)s bearing phthalazinone moiety (PPENKs) were successfully synthesized by the nucleophilic substitution reaction of 4-(4-hydroxylphenyl)-2,3-phthalazin-1(2H)-one (DHPZ), a new bisphenol-like monomer with twisted non-coplanar structure, with various molar proportions of 2,6-dichlorobenzonitrile (DCBN) to 4,4′-difluoro benzophenone (DFK) as coreactants in sulfolane at the present of anhydrous potassium carbonate. In order to obtain high-molecular weight polymers, DHPZ firstly polymerized with low-reactive DCBN for a given time at polymerization temperature after removal of water produced during the reaction, followed by addition of high-reactive DFK to continue the reaction until high-molecular weight polymers were obtained. These obtained copolymers had inherent viscosities between 0.45 and 0.80 dL/g in chloroform at a concentration of 0.5 g dL^?1 at 25 °C, and their number-average molecular weights were in the ranges from 2.2 × 10⁴ to 4.7 × 10⁴ with the polydispersity of 2.05–2.70. The structure of typical PPENK5050 was ambiguously confirmed by FT-IR and ¹H-NMR. All of the PPENKs were amorphous and soluble in dipolar aprotic solvents, involving N-methyl pyrrolidione, N,N-dimethylacetamide, and chloroform at room temperature. The resulting copolymers showed glass transition temperatures (T _gs) between 267 and 287 °C, and the T _g values of the copolymers were found to increase with increasing DCBN unit content in the polymer. Thermogravimetric studies showed that all of the polymers had 5 % weight loss temperatures ranging from 501 to 511 °C in nitrogen atmosphere. All of the PPENKs could be cast into transparent, strong, and flexible films. They displayed electrical surface resistivity of 10¹³ Ω, indicating their potential application in electronic field. Physical properties of PPENK5050, which exhibited the best mechanical properties, were measured according to ASTM plastic standards. The results indicated that PPENK5050 possessed excellent thermal properties with the heat deformation temperature of 270 °C, which was 100 °C higher than PEN? invented and commercialized by Idemitsu Kosan Company Limited. Its dielectric coefficient was 3.45 with the dielectric loss of 0.004 detected at 1 MHz. The other properties of PPENK5050 were equivalent to PEN?. They could be the promising materials as high-performance matrix in the application of polymer matrix composite, high-performance coating, adhesive, and membrane.     

Synthesis and properties of poly ether nitrile sulfone copolymers with pendant methyl groups

Poly ether nitrile and poly ether nitrile sulfone copolymers with pendant methyl groups were prepared by the nucleophilic substitution reaction of 2,6′‐dichlorobenzonitrile with methyl hydroquinone and with varying mole proportions of methyl hydroquinone and 4,4′dihydroxydiphenylsulfone using N‐methyl pyrrolidone as solvent in the presence of anhydrous K₂CO₃. The polymers were characterized by different physicochemical techniques. Copolymer composition was determined using FTIR technique. Thermogravimetric data reveals that all the polymers were stable up to 420°C with a char yield above 40% at 900°C in N₂ atmosphere. The glass transition temperature was found to increase and the activation energy and inherent viscosities were found to decrease with increase in concentration of the 4,4′‐dihydroxydiphenylsulfone units in the polymer. Trimerization reactions are found to be favorable with increase in concentration of methyl hydroquinone units in the polymer. Crystallinity of the polymer was also studied using wide angle X‐ray diffraction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1303–1309, 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     

Synthesis and properties of poly(ether nitrile sulfone) copolymers with pendant methyl groups

Poly(ether nitrile) and poly(ether nitrile sulfone) copolymers with pendant methyl groups were prepared by the nucleophilic substitution reaction of 2,6′‐dichlorobenzonitrile with methyl hydroquinone and with varying mole proportions of methyl hydroquinone and 4,4′‐dihydroxydiphenylsulfone using N‐methyl pyrrolidone as a solvent in the presence of anhydrous K₂CO₃. The polymers were characterized by different physicochemical techniques. Copolymer composition was determined using the FTIR technique. Thermogravimetric data revealed that all polymers were stable up to 420°C with a char yield above 40% at 900°C in a nitrogen atmosphere. The glass‐transition temperature increased and the activation energy and inherent viscosities decreased with an increase in the concentration of the 4,4′‐dihydroxydiphenylsulfone units in the polymer. Trimerization reactions were favorable with an increase in the concentration of methyl hydroquinone units in the polymer. The crystallinity of the polymer was also studied using wide‐angle X‐ray diffraction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1987–1994, 2005     

Synthesis and properties of novel copolymers of poly(ether ketone ether ketone ketone) and poly(ether ketone ketone ether ketone ketone) containing 1,4‐naphthylene moieties

A new monomer, 1,4‐bis(4‐phenoxybenzoyl)naphthalene (BPOBN), was conveniently synthesized via a simple synthetic procedure from readily available materials. A series of novel copolymers of poly(ether ketone ether ketone ketone) and poly(ether ketone ketone ether ketone ketone) containing 1,4‐naphthylene moieties were prepared by the Friedel‐Crafts acylation solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of BPOBN and 4,4′‐diphenoxybenzophenone (DPOBPN), over a wide range of BPOBN/DPOBPN molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone in 1,2‐dichloroethane. The copolymers with 10–40% BPOBN are semicrystalline and had remarkably increased T_gs over the conventional PEEK and PEKK due to the incorporation of 1,4‐naphthylene moieties in the main chains. The copolymers with 30–40 mol% BPOBN had not only high T_gs of 176–177°C, but also moderate T_ms of 332–338°C, which are suitable for the melt processing. These polymers had tensile strengths of 101.5–104.7 MPa, Young's moduli of 2.49–2.65 GPa, and elongations at break of 13.3–15.7% and exhibited high thermal stability and excellent resistance to organic solvents. POLYM. ENG. SCI., 56:566–572, 2016. © 2016 Society of Plastics Engineers     

Synthesis and characterization of phosphorus containing aromatic poly(amide-imide)s copolymers for high temperature applications

A series of novel thermally stable poly(amide-imide)s (PAIs) based on non-coplaner diimide-diacid (DIDA) monomer is synthesized. These polymers are characterized by elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR and ³¹P-NMR spectroscopic techniques and their physical and thermal properties are also studied. Four different dianhydrides pyromellitic anhydride (PMDA)/3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA)/1,4,5,8-naphthalene tetracarboxylic dianhydride (NTDA)/4,4′-oxydiphthalic anhydride (ODPA) and amino acid l-tryptophan are used to synthesize DIDA. The polymerization of DIDA with phosphorus containing triamines having phenyl moieties gives poly(amide-imide)s. The synthesized polymers are obtained in high yield and possessed inherent viscosity in the range 0.66–0.98 dL/g. These polymers display higher solubility in polar aprotic solvents, such as DMSO, NMP and DMF. In addition, the absorption edge values (λ _o) obtained from their UV curves are determined, and all the resulting poly(amide-imide)s films exhibited high optical transparency. The glass transition temperature (T _g) of these polymers is recorded in the range 211–265 °C, initial decomposition temperature in excess of 435 °C and char yield at 800 °C in nitrogen ranged from 52 to 70 %. Wide angle X-ray diffraction showed that all the polymers are almost amorphous.     

Physical and electrochemical behaviors of directly polymerized sulfonated poly(arylene ether ketone sulfone)s proton exchange membranes with different backbone structures

Sulfonated poly(ether ether ketone sulfone) (SPEEKS) and sulfonated poly(ether ether ketone ketone sulfone) (SPEEKKS) copolymers with different degree of sulfonation (DS) were synthesized by aromatic nucleophilic polycondensation of disodium 3,3′‐disulfonate‐4,4′‐dichloro‐diphenylsulfone (SDCDPS), tertbutylhydroquione, and 4,4′‐difluorobenzophenone or 1,4′‐bi(4‐fluorobenzoyl) benzene. Prepared sulfonated copolymers were characterized by Fourier transform infrared spectra, thermogravimetric analysis, and differential scanning calorimetry. The transmission electron microscope was used to investigate the microstructure of membranes. The different distance between two adjacent sulfonic groups in two series of membranes resulted in different physical and electrochemical properties between two kinds of membranes with the same DS. The proton conductivity, ionic exchange capacity and water uptake of SPEEKS membranes were higher than those of SPEEKKS membranes while the mechanical strength of SPEEKS membranes was lower than that of SPEEKKS membranes at the same DS. Moreover, the SPEEKKS membranes with DS equals to 0.8 showed a good combination of a high proton conductivity (0.046 S/cm at 25°C, 0.061 S/cm at 80°C), acceptable water uptake (33–65 wt %), excellent mechanical strength (tensile strength reached 49.7 MPa), and good thermal properties (T_g above 250°C, T_d5% above 300°C). It suggested that this could be a promising membrane for proton exchange membrane fuel cell application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis,optical, and thermal properties of polyimides containing flexible ether linkage

The goal of this article was to synthesize a series of flexible polyimides containing ether linkage in main chain and clarified the effect of this ether linkage on some physical properties such as optical and thermal decomposition. Also, different functional group effects such as carbonyl (? C?O), hexa‐fluoro‐isopropylidene [? C(CF₃)₂? ] and phenyl (? C₆H₅) on these physical properties were evaluated. The structural characterization of poly(ether imide)s was performed using Fourier transform infrared, ¹H‐nuclear magnetic resonance (NMR), and ¹³C‐NMR techniques. Optical band gap of polyimides was calculated in the range from 2.57 to 2.81 eV. Thermal characterization of poly(ether imide)s was carried out using thermogravimetry–differential thermal analysis and differential scanning calorimetry. Thermal stability of poly(ether imide)s was evaluated by initial decomposition temperature (T_on) and char. T_on value of polymers was determined in the range from 100 to 195 °C. In addition, glass transition temperatures of poly(ether imide)s were found between 144 and 148 °C. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46573.     

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     

Thermal properties,adhesive strength,and optical transparency of cyclolinear poly(aryloxycyclotriphosphazenes)

Four cyclolinear poly(aryloxycyclotriphosphazenes) derived from poly[4,4′‐(isopropoylidene)diphenoxytetrachlorocyclotriphosphazene] and poly[4,4′‐(hexafluoroisopropylidene)diphenoxytetrachlorocyclotriphosphazene] were synthesized from the reaction of hexachlorocyclotriphosphazene (HCP) with 4,4′‐(isopropylidene)diphenol (bisphenol A) or 4,4′‐(hexafluoroisopropylidene)diphenol (bisphenol AF) in molar ratio 1 : 1 via a one‐step condensation polymerization. Subsequent reaction of the resulted chlorine‐bound polymers with adequate amount of the sodium salts of 4‐methoxycarbonylphenoxide or 4‐propoxycarbonylphenoxide yielded the corresponding chlorine‐free polymers, [poly(tetra‐4‐methoxycarbonylphenoxy)‐4,4′‐(isopropoylidene)diphenoxy cyclotriphosphazene] (MBACP), [poly(tetra‐4‐propoxycarbonylphenoxy)‐4,4′‐(isopropoylidene)diphenoxycyclotriphosphazene] (PBACP), [poly(tetra‐4‐methoxycarbonylphenoxy)‐4,4′‐(hexafluoroisopropylidene)diphenoxycyclotriphosphazene] (MBAFCP), [poly(tetra‐4‐propoxycarbonylphenoxy)‐4,4′‐(hexafluoroisopropylidene)diphenoxycyclotriphosphazene] (PBAFCP), respectively. The chemical structures were characterized by Fourier transformer infrared, ¹H, and ¹³C‐NMR. Thermal properties of polymers were investigated using DSC and TGA analysis. The obtained polymers were thermoplastic, having moderate T_g values in the range of 26–78°C and good thermal stability up to 350°C in N₂ and O₂ gases. The thermal decomposition of the isopropylidene‐containing polymers is a one‐step process, while that of hexafluoroisopropylidene‐containing polymers is a two‐step process. However, presence of the latter group in the polymers backbone showed negligible effects on the thermo‐oxidative stability. The adhesive strength was measured by lap‐shear strength test on glass–glass bonded joint and found to be in the range of 1.78–2.62 MPa, this property may be attributed to the physical interactions between glass–glass interfaces and the polar‐pendant units present at the polymers backbone. The products showed high optical transparency when they applied between two glass surfaces, the adhesive layers were colorless, with the UV cut‐off wavelength of 300–302 nm, and the maximum transparency of about 90% was observed within the wavelengths range of 400–700 nm. Because of their properties, the cyclolinear poly(aryloxycyclotriphosphazenes) synthesized in this study are recommended as potential candidates for high thermally stable, transparent adhesives required in industrial applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.