Synthesis, light emission, and photo-cross-linking of luminescent polyacetylenes containing acrylic pendant groups

New poly(1-phenyl-1-alkyne)s bearing acrylic pendants (-{(C₆H₅)CC[(CH₂)_mOCOCHCH₂]}_n-; P1(m), m=3, 9) with high molecular weights are synthesized in high yields by WCl₆-Ph₄Sn catalyst. The structures and properties of P1(m) are characterized and evaluated by IR, NMR, TGA, UV, and PL analyses. All the polymers are solution-processable and thermally stable (T_d≥380 °C). Upon photoexcitation, the polymers emit strong blue lights with emission efficiencies (>40%) comparable to that of poly(1-phenyl-1-octyne), an emissive disubstituted polyacetylene. No excimeric absorption and emission are observed in the thin films of the polymers. The acrylic moieties of P1(m) are readily cross-linked by UV irradiation without harming their optical properties, which may enable them to find high-tech applications in photoresist, luminescent patterning, and light-emitting diodes.     

Poly(naphthylenethiophene)s and poly(naphthylenevinylenephenylenevinylene)s: effect of naphthalene positional isomers on the light emitting properties of their polymers

Poly(naphthylenethiophene)s and poly(naphthylenevinylene-phenylenevinylene)s prepared from 1,5-dibromo-3,7-di-t-butylnaphthalene showed a significant blue shift in their UV-vis and photoluminescence spectra compared to copolymers derived from the 1,4-naphthylene system, both in solution and in thin film. This is correlated to a change in conjugation effect of the two positional isomers of naphthalene in the polymer backbone, where in 1,4-conjugation an aromatic sextet remains intact in one of the naphthalene rings whereas 1,5-conjugation involves the loss of resonance energy in the entire naphthalene unit. The series of poly(naphthylenevinylene-phenylvinylene)s emitted blue-green light with very high fluorescence quantum yields (80-95%) in solution. A fabricated device showed external quantum efficiency estimated at 0.2-0.4%, with a relatively high turn-on voltage at ∼7.0 V.     

Synthesis, characterization, and high gas permeability of poly(diarylacetylene)s having fluorenyl groups

Diarylacetylenes having fluorenyl groups and other substituents (trimethylsilyl, t-butyl, bromine, fluorine) (1a-1) were polymerized with TaCl₅-n-Bu₄Sn. Monomers 1a-l produced high molecular weight polymers 2a-l (M_w 5.1 × 10⁵-1.3 × 10⁶) in 12-59% yields. All of the polymers were soluble in common organic solvents, and gave tough free-standing membranes by the solution casting method. The onset temperatures of weight loss of polymers 2a-l in air were over 400 °C, indicating considerably high thermal stability. All the polymer membranes showed high gas permeability; e.g., the oxygen permeability coefficient (PO₂) of 2a was as large as 4800 barrers. Membrane 2d possessing two fluorine atoms at meta and para positions of the phenyl ring showed the highest oxygen permeability (PO₂ = 6600 barrers) among the present polymers.     

Synthesis,characterization, and thermal stability of novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s bearing pendant groups and their corresponding poly(ether-amide-1,3,4-oxadiazole)s

Four novel wholly para-oriented aromatic poly(ether-amide-hydrazide)s containing various pendant groups on their aromatic rings were synthesized from p-aminosalicylic acid hydrazide (PASH) with an equimolar amount of either 4,4′-(1,4-phenylenedioxy)dibenzoyl chloride (1a), 4,4′-(2,5-tolylenedioxy)dibenzoyl chloride (1b), 4,4′-(2-tert-butyl-1,4-phenylenedioxy)dibenzoyl chloride (1c), or 4,4′-(2,5-biphenylenedioxy)dibenzoyl chloride (1d) via a low temperature solution polycondensation reaction. A polyamide-hydrazide without the ether and pendant groups, poly[4-(terephthaloylamino)salicylic acid hydrazide, PTASH, is also investigated for comparison. It was synthesized from PASH and terephthaloyl chloride by the same synthetic route. The polymer intrinsic viscosities ranged from 4.5 to 2.47 dlg⁻¹ in N,N-dimethyl acetamide (DMAc) at 30 °C and decreased with the introduction of the ether and pendant groups into the polymer. All the polymers were soluble in DMAc, N,N-dimethyl formamide (DMF), and N-methyl-2-pyrrolidone (NMP) and their solutions could be cast into flexible films with good mechanical strengths. Further, they exhibited a great affinity to water sorption. Their solubility and hydrophilicity increased with introduction of the ether and pendant groups into the polymer. The prepared polymers could be thermally cyclodehydrated under nitrogen atmosphere into the corresponding poly(ether-amide-1,3,4-oxadiazole)s approximately in the region of 300–450 °C. The introduction of the flexibilizing ether linkages and the pendant groups into the polymer improves the solubility of the resulting poly(ether-amide-1,3,4-oxadiazole)s compared to poly(amide-1,3,4-oxadiazole) free from these groups.     

Synthesis and properties of poly(phenylacetylene)s with pendant imino groups

Summary Polymerization of phenylacetylenes containing imino groups with a variety of transition metal catalysts was investigated. The monomers employed were N-(4-ethynylbenzylidene)aniline (1), N-(3-ethynylbenzylidene)aniline (2), N-(4-ethynylbenzylidene)-2,6-diisopropylaniline (3), N-(4-ethynylbenzylidene)-4-hexylaniline (4), N-(4-ethynylbenzylidene)butylamine (5), and N-(4-ethynylbenzylidene)octylamine (6). All of the monomers smoothly polymerized with [(nbd)RhCl]₂-Et₃N to give polymers in excellent yields, whereas no polymerization took place with W, Mo, and Fe catalysts. The produced polymers were orange to red solids and soluble in common organic solvents except for poly(1). UV-vis spectra of the polymers indicated that the main chains possess a similar degree of conjugation to that of poly(phenylacetylene). However, the stability of polymer backbone toward oxidative cleavage in solution remarkably improved, which is contributed by the electron-withdrawing character of imino groups. Received: 24 August 1999/Accepted: 29 September 1999     

Synthesis and characterization of poly(vinylether)s with pendant mesogenic groups

Two different methods of synthesis were examined for the preparation of poly(alkylvinylether)s with pendant 4-cyano-4-oxy-biphenyl mesogenic groups attached to side chains of different length: a) anchoring of the mesogenic group onto an alkylvinylether monomer followed by polymerization or b) synthesis of the corresponding poly(chloroalkylvinylether)s and chemical substitution of the pendant chlorine by the mesogenic groups. Polymerization were performed with initiating systems based on activated iodide. Much better control of MW and MWD of the final polyvinylether chains was obtained when process b) was applied. Polymers with 2 and 4 carbons in the spacer do not show liquid crystalline properties. It is only with polymers having six carbon atoms in the spacer that mesophases were observed. Those issued from process b) give two distinct mesophases: a smectic A phase in the high temperature range and a smectic C phase for the low one. Polymers synthetized from process a) present only the smectic A phase. The effects of molecular weights and molecular weight distributions on the liquid crystalline properties have been examined and are discussed.     

Synthesis and gas permeation properties of various Si-containing poly(diarylacetylene)s and their desilylated membranes

Diarylacetylene monomers having trimethylsilyl groups and other substituents (substituted biphenyl, 1a and 1b; trimethylsilylmethylphenyl, 1c-e) were synthesized and polymerized with TaCl₅-n-Bu₄Sn catalyst to produce the corresponding poly(diarylacetylene)s (2a-d). Polymers 2a-c had high molecular weights and were soluble in common organic solvents. Free-standing membranes of 2a-c as well as previously reported 2f-h were prepared by the solution-casting method. Desilylation of these Si-containing polymer membranes was carried out with trifluoroacetic acid to afford 3a, 3b, and 3f-h. Upon desilylation, biphenyl-containing membranes became less permeable (3a, b), whereas fluorene-containing membranes became more permeable (3f-h). In particular, 3h exhibited extremely high gas permeability (PO₂ = 9800 barrers), which is about the same as that of poly(1-trimethylsilyl-1-propyne). Desilylated membranes 3a and 3f-h showed different gas permeability from that of polymers 2i-k which have the identical chemical structures and obtained directly by the polymerization of the corresponding monomers.     

Synthesis and stable high oxygen permeability of poly(diphenylacetylene)s with two or three trimethylsilyl groups

We synthesized two new poly(diphenylacetylene)s having two or three trimethylsilyl groups and found these membranes having extremely high oxygen permeabilities of more than 1000 barrers which are of the same order as that for poly[1-(trimethylsilyl)-1-propyne]. Whereas oxygen permeability of poly[1-(trimethylsilyl)-1-propyne] was reported to decrease largely with time, these high oxygen permeabilities were stable for several months. These membranes also showed ethanol permselectivities because of their hydrophobicity. It was found that the introduction of two or three trimethylsilyl groups to poly(diphenylacetylene) was very effective for obtaining stable high oxygen permeable and ethanol permselective membranes.     

Synthesis and characterization of novel aromatic poly(ester amide)s containing pendant trifluoromethylphenoxy groups

A new diamine monomer, 1,4-bis(4-aminophenoxycarbonyl)-2-(4-trifluoromethylphenoxy)benzene containing the trifluoromethyl and ester groups, was prepared from 2-(4-trifluoromethylphenoxy)terephthalyol chloride and 4-nitrophenol in two steps. Then, a series of novel aromatic poly(ester amide)s containing pendant trifluoromethylphenoxy groups with inherent viscosities of 0.51–1.14 dL/g have been prepared by low-temperature solution polycondensation from this diamine with various aromatic diacid chlorides. All the poly(ester amide)s are amorphous and readily soluble in many organic solvents such as N,N-dimethylacetamide (DMAC) and dimethyl sulfoxide. Tough and flexible polymer films cast from DMAc solutions have tensile strengths of 89–114 MPa, elongations at break of 5.8–8.8%, and initial moduli of 2.2–3.2 GPa. These poly(ester amide)s show glass transition temperatures between 166 and 256°C, 10% weight loss temperatures ranging from 395 to 445°C, and char yields higher of 46–56% at 800°C in nitrogen, and also exhibit low dielectric constants ranging from 3.31 to 3.52 (1 MHz), and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 362–380 nm range. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of soluble fluorinated poly(ether imide)s with different pendant groups

Two types of new fluorinated diamine monomer, [1,4-(4-amino-2-trifluoromethyl-phenoxy)-2-(3′-trifluoromethylphenyl) benzene (III)] and [1,4-(4-amino-2-trifluoromethyl-phenoxy)-2-(3′-methylphenyl) benzene (IV)] were synthesized and polymerized with aromatic dianhydrides. A series of soluble poly(ether imide)s (PEIs) were prepared from the diamines and dianhydrides by two-step chemical imidization methods. Experimental results indicated that all the PEIs had glass transition temperature between 230 °C and 247 °C, the temperature at 5% weight loss between 527 °C and 598 °C under nitrogen. The membranes hand tensile strengths in the range of 74-101 MPa, tensile modulus in the range of 1.9-2.6 GPa, and elongation at break from 20 to 28%. The cast membranes also exhibited high optical transparency, with a UV-vis absorption edge of 354-406 nm. Moreover, these PEIs membranes possessed low dielectric constants of 2.63-3.20 (at 1 MHz) and low water uptakes (<0.75 wt%).     

Synthesis,optical, electrochemical,and thermal stability properties of poly(azomethine-urethane)s

In this study, the novel low band gap and thermally stable poly(azomethine-urethane)s (PAMUs) were synthesized to investigate aliphatic and aromatic group effects on some physical properties such as thermal stability, optical and electrochemical properties. For this reason, we firstly synthesized the new Schiff bases via condensation reaction of 5-nitrovanilin with aromatic and aliphatic diamines. Then, these monomers were converted to PAMUs derivatives by the step-polymerization reaction with aromatic and aliphatic diisocyanates. The structures of the compounds were confirmed by FT-IR, UV–vis, ¹H NMR, and ¹³C NMR techniques. The molecular weight distribution parameters of the compounds were determined by the size exclusion chromatography (SEC). The compounds were also characterized by solubility tests, TG–DTA, and DSC techniques. Cyclic voltammetry (CV) measurements were carried out and HOMO–LUMO energy levels and electrochemical band gaps (E^′g${E^{\prime }}_g$) were calculated from their absorption edges. Additionally, optical band gaps (E_g) were determined by using UV–vis spectra of the materials. Fluorescence measurements were carried out in THF, DMF, and DMSO solutions to determine the optimum concentrations and the maximal emission and excitation intensities.     

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,photophysical properties,and electron paramagnetic resonance studies of new poly(bisbenzothiazole)s containing bulky pendant groups

A new series of poly(bisbenzothiazole)s containing bulky pendant cyclohexylidene or 4‐tert‐butylcyclohexylidene group was synthesized. Their structures were characterized by NMR (¹H, ¹³C), FTIR, and EA. These polymers exhibited good solubility, thermal stability, and an amorphous nature. The photophysical properties of them were investigated in detail by UV absorption spectroscopy and photoluminescence spectroscopy. Compared with poly(p‐phenylene benzobisthiazole), the absorption maxima of these polymers were all blue shifted, and their optical bandgaps were increased. The emission peaks, having different intensity, were also blue shifted. They both changed in shape and position gradually with the increasing concentration, which showed the evidence of aggregate formation. In addition, the degree of aggregation was decreased with the increasing size of bulky pendant group and the PL quantum yield could be improved by the introduction of bulky pendant group. The result of electron paramagnetic resonance studies showed the intrinsic paramagnetic defects in this class of polymers. A new soliton–antisoliton model was constructed to interpret these intrinsic paramagnetic signals. POLYM. ENG. SCI., 47:429–438, 2007. © 2007 Society of Plastics Engineers.     

Synthesis and characterization of poly(ether ketone ether ketone ketone)/poly(ether ether ketone ketone) copolymers containing naphthalene and pendant cyano groups

2,6‐Bis(β‐naphthoxy)benzonitrile (BNOBN) was synthesized by reaction of β‐naphthol with 2,6‐difluorobenzonitrile in N‐methyl‐2‐pyrrolidone (NMP) in the presence of KOH and K₂CO₃. Poly(ether ketone ether ketone ketone)(PEKEKK) /poly(ether ether ketone ketone) (PEEKK) copolymers containing naphthalene and pendant cyano groups were obtained by electrophilic Friedel‐Crafts polycondensation of terephthaloyl chloride (TPC) with varying mole proportions of 4,4′‐diphenoxybenzophenone (DPOBP) and 2,6‐bis(β‐naphthoxy)benzonitrile (BNOBN) using 1,2‐dichloroethane (DCE) as solvent and NMP as Lewis base in the presence of anhydrous AlCl₃. The resulting polymers were characterized by various analytical techniques, such as FTIR, DSC, TG, and WAXD. The results indicated that the crystallinity and melting temperature of the polymers decreased with increase in concentration of the BNOBN units in the polymer, the glass transition temperature of the polymers increased with increase in concentration of the BNOBN units in the polymer. Thermogravimetric studies showed that all the polymers were stable up to 536°C in N₂ atmosphere. The copolymers have good resistance to acidity, alkali, and organic solvents. Because of the melting temperature (T_m) depression with increase in the BNOBN content in the reaction system, the processability of the resultant coplymers could be effectively improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The crosslinked poly(azomethine-urethane)s containing o-hydroxyazomethine: Tunable multicolor emission,photophysical and thermal properties

This article presents synthesis, photophysical, electrochemical, thermal, and morphological properties of the crosslinked polyurethanes (CLPUs). CLPUs were synthesized in two main steps. In the first step, aldehyde functionalized polyurethane prepolymer was synthesized using 2,4-dihydroxy benzaldehyde and hexamethylene diisocyanates. In the second step, the prepared prepolymer was converted to the crosslinked polyurethane derivatives using different diamines via condensation reaction. Diamines with various chain length and side-group substitutions were used as crosslinker. Photophysical properties of the crosslinked polyurethanes were investigated using UV–vis and photoluminescence (PL) spectra techniques. Fluorescence measurements showed that CLPUs exhibited multicolor emission behavior. Additionally, a linear relationship is determined between the excitation energies and the obtained emission maxima and, this property allows tuning the PL color by changing the source light energy on the desired scale.     

含醚基及氰侧基的聚芳酰胺的合成与表征

以二甲基乙酰胺为溶剂,叔胺为盐酸吸收剂,将4,4′-二氨基二苯醚与2,6-二(4-氯甲酰苯氧基)苯甲腈进行低温缩聚反应,合成含氰侧基及醚基结构的聚芳酰胺。结果表明:当反应体系摩尔浓度为0.45～0.55mol/L,初始反应温度为0℃,以2-甲基吡啶为盐酸吸收剂时,制得的聚芳酰胺相对分子质量较高,该聚合物热分解温度(失重5%)为419℃。     

Synthesis and characterization of poly(terphenylenevinylene) derivatives containing alkoxy substituents and (or) phenyl pendant group

The blue electroluminescent polymers, poly(terphenylenevinylene) derivatives that have advantages of PPP and PPV, were prepared by Suzuki coupling reaction. The structure and properties of the polymers were analyzed by various spectroscopic methods. Poly(MHTPPV) and poly(TPPV) with phenyl pendant group in a vinyl bridge showed blue shifted absorption spectra, large band gap and enhanced thermal stability as compared with that of poly(MHTPV). The PL spectra of the films of the polymers showed maximum peaks at 450-460 nm, which are pure blue emissions. The blue electroluminescence was obtained with the turn on voltage of 8-10 V, when the simple light-emitting diodes of ITO/polymer/Al were fabricated. The excimer emission due to interchain interaction was reduced by the introduction of substituents into the vinyl bridge and (or) the main chain.     

Novel poly(diphenylacetylene)s with both alkyl and silyl groups as gas permeable membranes: Synthesis, desilylation, and gas permeability

Diphenylacetylenes having a dimethyloctylsilyl group and an alkyl group at para positions [Me₂n-C₈H₁₇SiC₆H₄CCC₆H₄R; R = H (1a), i-Pr (1b), t-Bu (1c), n-Bu (1d)] and having only an alkyl group [PhCCC₆H₄R; R = i-Pr (1B), t-Bu (1C)] were synthesized and then polymerized with TaCl₅/n-Bu₄Sn catalyst to provide the corresponding poly(diphenylacetylene)s (2a, 2b, 2c, 2d, 2B, and 2C). The formed polymers afforded tough free-standing membranes by casting from toluene solutions. Desilylation reaction of Si-containing membranes (2a-d) was carried out with trifluoroacetic acid to give the desilylated membranes (3a-d). The permeability of these membranes to O₂, N₂, and CO₂ were determined. All the Si-containing membranes exhibited almost the same gas permeability. The desilylation of Si-containing membranes of 2a-c resulted in large increase of gas permeability. No apparent increasing of gas permeability was observed in the desilylation of 2d. To clarify the effects of desilylation, CO₂ diffusivity (D(CO₂)), CO₂ solubility (S(CO₂)), and fractional free volume (FFV) of the polymer membranes were investigated. The S(CO₂) values of desilylated membranes were much larger than that of Si-containing counterparts. The D(CO₂) and FFV of membranes of 2a-c increased through desilylation. The desilylated membrane of 3d had small D(CO₂) value and almost the same FFV compared with 2d. Further, the comparison of the permeability between three types of membranes with the same chemical structure revealed that the microvoids were not generated by the desilylation of membranes of poly(diphenylacetylene)s containing alkyl groups.     

Synthesis of PEG‐functionalized poly(diphenylacetylene)s and their gas permeation properties

The polymerizations of 1‐(3‐methylphenyl)‐2‐(4‐trimethylsilyl)phenylacetylene ( 1a ) and 1‐(4‐methylphenyl)‐2‐(4‐trimethylsilyl)phenylacetylene ( 1b ) were carried out with TaCl₅‐n‐Bu₄Sn to give relatively high‐molecular‐weight polymers ( 2a and 2b ) (M_n > 5 × 10⁵). The obtained polymers were brominated by using benzoyl peroxide and N‐bromosuccinimide first, followed by substitution reaction of three types of polyethylene glycol. When diethylene glycol was used as a reagent on substitution reaction of meta‐substituted polymer, PEG‐functionalized poly(diphenylacetylene) with the highest content of oxyethylene unit [ 4a(2) ] was obtained, and the degree of substitution was 0.60. The degrees of substitution decreased to 0.15 and 0.08 when the polyethylene glycols with higher molecular weights were used. PEG‐substitution reaction to the para‐substituted polymers was difficult to proceed, and hence the degree of substitution was 0.18 even when diethylene glycol was used. The CO₂/N₂ separation factor of PEG‐functionalized polymer [ 4a(2) ] was as large as 28.8, although that of 2a was 7.41. The other PEG‐functionalized polymers also exhibited high CO₂ permselectivity, and their CO₂/N₂ separation factors were over 20. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Poly(arylene ether)s carrying pendant (3‐sulfonated) phenylsulfonyl groups

A series of poly(arylene ether)s with biphenyl units and pendant sulfonated phenylsulfonyl groups was prepared via nucleophilic aromatic substitution reactions of varying ratios of 3,5‐difluoro‐3′‐sulfonated diphenylsulfone and 4,4′‐difluorodiphenylsulfone with 4,4′‐biphenol. As such, the sulfonic acid moieties reside in the meta position of a pendant, electron‐poor phenylsulfonyl group. Mechanically robust proton‐exchange membranes with ion‐exchange capacities (IEC) ranging from 0.91 to 2.05 meq g^?1 were cast from dimethylacetamide. The thermal stability of the membranes was evaluated via thermogravimetric analysis and the 5% weight losses were found to be in excess of 330 °C in air. The glass transition temperatures were determined, via differential scanning calorimetry, to range from a low of 148 to a high of 209 °C at IEC values of 0.91 and 1.79 meq g^?1, respectively. The copolymer membranes reached proton conductivities as high as 142 mS cm^?1 under 100% relative humidity, with relatively low water uptake values (8–32 wt%). Copyright © 2012 Society of Chemical Industry