Synthesis and characterization of poly(benzobisthiazole) with tetramethylbiphenyl moiety in the main chain

Poly(benzobisthiazole)s containing an ortho-tetramethyl substituted biphenyl moiety were synthesized via the polycondensation of 2,5-diamino-1,4-benzenedithiol dihydrochloride with 2,2′,6,6′-tetramethylbiphenyl-4,4′-dicarboxylic acid in poly(phosphoric acid) (PPA). The intrinsic viscosities of the tetramethylbiphenyl poly-(benzobisthiazole)s in chlorosulfonic acid at 30°C were in the range of 6.9–13.4 dL/g. Copolycondensation of 2,5-diamino-1,4-benzenedithiol dihydrochloride with terephthalic acid and 2,2′,6,6′-tetramethylbiphenyl-4,4′-dicarboxylic acid was carried out as well by varying the ratio of the two dicarboxylic acid monomers in the reactant mixture. The homopolymers and copolymers were characterized by Fourier transform infrared spectroscopy (FTIR) and ¹³C solid-state nuclear magnetic resonance spectroscopy (NMR). Thermal stability of the polymers was evaluated by thermogravimetric analysis (TGA) and thermogravimetric mass spectrum analysis (TG-MS). The tetramethylbiphenyl poly(benzobisthiazole)s were found to be more stable at elevated temperatures than the parent poly(p-phenylene benzobisthiazole) (PBZT). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1407–1416, 1998     

Preparation and characterization of fluorine-containing aromatic condensation polymers. VI. Aromatic polybenzothiazoles from 4,4′-(hexafluoroisopropylidene)dibenzoic acid and tetrafluoroterephthalic acid and 2,5-diamino-1,4-benzenedithiol dihydrochloride

Two fluorine-containing aromatic polybenzothiazoles were synthesized by direct polycondensation of 4,4′-(hexafluoroisopropylidene)dibenzoic acid and tetrafluoroterephthalic acid with 2,5-diamino-1,4-benzenedithiol dihydrochloride using phosphorus pentoxide/methanesulfonic acid or polyphosphoric acid as both condensing agent and solvent. The effect of introduction of fluorine atom on the synthesis and properties of these polymers was discussed in detail. The perfluoroisopropylidene unit-containing polybenzothiazole was amorphous, and showed good solubility in organic solvents, excellent mechanical properties, and high thermal stability. The perfluoro-p-phenylene unit-containing polybenzothiazole was crystalline, and exhibited lyotropic behavior in concentrated sulfuric acid. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36 : 429–435, 1998     

Synthesis,characterization, and properties of colorless rigid-rod poly(benzobisthiazole) derived from bicyclo[2.2.2]octane

Polycondensation in polyphosphoric acid of 2,5-diamino-1,4-benzene dithiol dihydrochloride with bicyclo[2.2.2]octane-1,4-dicarboxylic acid, as well as the corresponding dimethyl ester or diacid chloride, led to rigid-rod benzobisthiazole polymers. Colorless and soluble polymers with intrinsic viscosities as high as 30.6 dL/g (methanesulfonic acid, 30°C) were obtained. The ultraviolet-visible spectrum of a polymer film cast from methanesulfonic acid under reduced pressure displayed no absorptions in the visible range (400–900 °m). The polymer was thermooxidatively stable up to 420°C in air as determined by thermogravimetric analysis. Fibers spun from a lyotropic polyphosphoric acid solution exhibited a tensile strength of 300–450 Ksi, a modulus of 26 Msi, and a compressive strength of 53 Ksi. Wide-angle X-ray scattering patterns of polymer fibers indicated a 3-dimensional crystal structure rather than a nematic liquid crystal structure. © 1994 John Wiley & Sons, Inc.     

New aromatic benzazole polymers II: Synthesis and conductivity of benzobisthiazole-co-polymers incorporated with 4-N,N-dimethylaminotriphenylamine groups

New aromatic benzobisthiazole copolymers containing 10–70 mol % of 4-N,N-dimethylamino-triphenylamine functionality were prepared from the respective dinitrile or dicarboxylic acid monomers, terephthalic acid, and 2,5-diamino-1,4-benzene-dithiol dihydrochloride in polyphosphoric acid. At the first approximation, the copolymers containing 10 mol % or less of the triarylamino moieties in the polymer chains still preserve the capability to form anisotropic (nematic) solutions at 10 wt % polymer concentration. This is an important requirement for processing the copolymers into fibers and films with good to excellent mechanical properties. Films with good mechanical integrity were cast from the dilute methanesulfonic acid solutions of the copolymers under reduced pressure. They showed electrical conductivity values of the order of 10⁻¹¹–10⁻¹⁰ S/cm in pristine state, with four to seven orders of magnitude increase upon exposure to mild oxidizing agents such as iodine vapor. On the contrary, the parent polymer, poly(p-phenylene benzobisthiazole) is an insulator with conductivity of less than 10⁻¹² S/cm, and its conductivity does not improve at all with exposure to iodine vapor. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 713–724, 1998     

Synthesis of aliphatic polyimides containing adamantyl units

Aliphatic polyimides containing adamantyl units (APIs) were prepared by the poly(addition/condensation) of a dianhydride bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic 2,3 : 5,6-dianhydride with a rigid diamine, 1,3-diaminoadamantane or 3,3′-diamino-1,1′-biadamantyl, and a flexible diamine, 4,4′-methylenebis(cyclohexylamine) or 1,4-cyclohexanediamine. One-step polymerizations were conducted at 80–200°C in m-cresol, producing APIs with inherent viscosities up to 0.53 dL g⁻¹. These APIs are soluble in haloalkanes, m-cresol, and sulfuric acid and show high thermal stability and excellent transparency. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3584–3590, 1999     

New aromatic benzazole polymers. I. Benzobisthiazole and benzobisoxazole polymers with main-chain triarylamino units

Thermally stable, nonrigid-rod poly(benzobisthiazoles), (R)TPA-PBZT , where R = H, Me, NMe₂, and OH, and poly(benzobisoxazoles), (R)TPA-PBO , where R = Me, NMe₂ containing electron-rich triarylamine groups with various para-substituents (Rs) on the pendent phenyl ring, were synthesized from either 2,5-diamino-1,4-benzenedithiol dihydrochloride or 2,4-diamino-1,5-benzenediol dihydrochloride and the respective triarylamine-based dinitrile or diacid monomer in polyphosphoric acid. Whereas (R)TPA-PBZT polymers were obtained in moderate molecular weights, analogous (R)TPA-PBO polymers were only prepared in low molecular weights. No lyotropic behaviors, characteristic of the unmodified rigid-rod benzazole polymers, as evidenced by the absence of either stir opalescence or birefringence under crosspolarizers, were observed for these homopolymers at about 10 wt % polymer concentration. Among these polymers, only (Me)TPA-PBZT and (NMe₂)TPA-PBZT formed cast films with good mechanical integrity. In their pristine state, their film conductivity values were in the range of 10⁻¹⁰–10⁻⁹ S/cm at room temperature. Upon exposure to iodine vapor, their conductivities were increased to the maximal values of 5.0 × 10⁻⁵ S/cm ( (Me)TPA-PBZT ) and 4.1 × 10⁻⁴ S/cm ( (NMe₂)TPA-PBZT ). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1909–1924, 1997     

Biobased poly(2,5‐furandimethylene succinate‐co‐butylene succinate) crosslinked by reversible Diels–Alder reaction

We synthesized biobased poly(2,5‐furandimethylene succinate‐co‐butylene succinate) [P(FS‐co‐BS)] copolymers by polycondensation of 2,5‐bis(hydroxymethyl)furan, 1,4‐butanediol, and succinic acid. These copolymers could be crosslinked to form network polymers by means of a reversible Diels–Alder reaction with bis‐maleimide. The thermal properties, mechanical properties, and healing abilities of the P(FS‐co‐BS)s and the network polymers were investigated. The mechanical properties of the network polymers depended on the comonomer composition of the P(FS‐co‐BS)s and the maleimide/furan ratio in the network polymers. Some of the copolymers exhibited healing ability at room temperature, and their healing efficiency was enhanced by solvent or heat. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 216–222     

Synthesis and characterization of poly(benzobisthiazole)s derived from halogenated phthalic acid and isophthalic acid

Poly(benzobisthiazole)s containing tetrafluorophenyl and bromophenyl moieties were synthesized via the polycondensation of 2,5‐diamino‐1,4‐benzenedithiol dihydrochloride with tetrafluorophthalic acid and 4‐bromoisophthalic acid under a nitrogen atmosphere. The polymers were characterized by X‐ray diffraction, spectroscopy (infrared and solid‐state ¹³C NMR), and thermal analysis, including differential scanning calorimetry and thermogravimetric analysis. The thermogravimetric analysis showed that the thermal stability of the polymers was 490–515 °C under a nitrogen atmosphere. The synthesized polymers showed good solubility in organic solvents. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3959–3966, 2002     

Synthesis and comparison of the structure–property relationships of symmetric and asymmetric water‐soluble poly(p‐phenylene)s

Sodium salts of water‐soluble polymers poly{[2,5‐bis(3‐sulfonatopropoxy)‐1,4‐phenylene]‐alt‐[2,5‐bis(hexyloxy)‐1,4‐phenylene]} ( P1 ), poly{[2,5‐bis(3‐sulfonatopropoxy)‐1,4‐phenylene]‐alt‐[2,5‐bis(dodecyloxy)‐1,4‐phenylene]} ( P2 ), poly{[2,5‐bis(3‐sulfonatopropoxy)‐1,4‐phenylene]‐alt‐[2,5‐bis(dibenzyloxy)‐1,4‐phenylene]} ( P3 ), poly[2‐hexyloxy‐5‐(3‐sulfonatopropoxy)‐1,4‐phenylene] ( P4 ), and poly[2‐dodecyloxy‐5‐(3‐sulfonatopropoxy)‐1,4‐phenylene] ( P5 )] were synthesized with Suzuki coupling reactions and fully characterized. The first group of polymers ( P1 – P3 ) with symmetric structures gave lower absorption maxima [maximum absorption wavelength (λ_max) = 296–305 nm] and emission maxima [maximum emission wavelength (λ_em) = 361–398 nm] than asymmetric polymers P4 (λ_max = 329 nm, λ_em = 399 nm) and P5 (λ_max = 335 nm, λ_em = 401 nm). The aggregation properties of polymers P1 – P5 in different solvent mixtures were investigated, and their influence on the optical properties was examined in detail. Dynamic light scattering studies of the aggregation behavior of polymer P1 in solvents indicated the presence of aggregated species of various sizes ranging from 80 to 800 nm. The presence of alkoxy groups and 3‐sulfonatopropoxy groups on adjacent phenylene rings along the polymer backbone of the first set hindered the optimization of nonpolar interactions. The alkyl chain crystallization on one side of the polymer chain and the polar interactions on the other side allowed the polymers ( P4 and P5 ) to form a lamellar structure in the polymer lattice. Significant quenching of the polymer fluorescence upon the addition of positively charged viologen derivatives or cytochrome‐C was also observed. The quenching effect on the polymer fluorescence confirmed that the newly synthesized polymers could be used in the fabrication of biological and chemical sensors. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3763–3777, 2006     

Diketopyrrolopyrrole‐based liquid crystalline conjugated donor–acceptor copolymers with reduced band gap for polymer solar cells

A new liquid crystalline (LC) acceptor monomer 2,5‐bis[4‐(4′‐cyanobiphenyloxy)dodecyl]‐3,6‐dithiophen‐2‐yl‐pyrrolo[3,4‐c]pyrrole‐1,4‐dione (TDPPcbp) was synthesized by incorporating cyanobiphenyl mesogens into diketopyrrolopyrrole (DPP). The monomer was copolymerized with bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′] dithiophene (BDT) and N‐9′‐heptadecanylcarbazole (CB) donors to obtain donor–acceptor alternating copolymers poly[4,8‐bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′]dithiophene‐alt‐3,6‐bis(thiophen‐5‐yl)‐2,5‐bis[4‐(4′‐cyanobiphenyloxy)dodecyl]‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione] (PBDTDPPcbp) and poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐3,6‐bis(thiophen‐5‐yl)‐2,5‐bis[4‐(4′‐cyano‐biphenyloxy)dodecyl]‐2,5‐dihydropyrrolo[3, 4‐c]pyrrole‐1,4‐dione] (PCBTDPPcpb) with reduced band gap, respectively. The LC properties of the copolymers, the effects of main chain variation on molecular packing, optical properties, and energy levels were analyzed. Incorporating the mesogen cyanobiphenyl units not only help polymer donors to pack well through mesogen self‐organization but also push the fullerene acceptor to form optimized phase separation. The bulk heterojunction photovoltaicdevicesshow enhanced performance of 1.3% for PBDTDPPcbp and 1.2% for PCBTDPPcbp after thermal annealing. The results indicate that mesogen‐controlled self‐organization is an efficient approach to develop well‐defined morphology and to improve the device performance. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Rigid-Rod benzobisthiazole polymers with reactive fluorene moieties: Synthesis and characterization

High purity 2,7-fluorenedicarboxylic acid chloride was synthesized in a multistep reaction scheme from 2,7-dibromofluorene. Subsequent polycondensation in polyphosphoric acid of 2,5-diamino-1,4-benzenedithiol dihydrochloride with terephthaloyl chloride and 2,7-fluorenedicarboxylic acid chloride led to rigid-rod benzobisthiazole polymers with reactive fluorene moieties. The proportion of fluorene in the resultant polymers was controlled through reaction stoichiometry. Soluble polymers with intrinsic viscosities as high as 33.7 dL/g (methanesulfonic acid, 30°C) were obtained if the polymerization temperature was not allowed to exceed 165°C. Insoluble, presumably crosslinked polymers were obtained at higher temperature (190–200°C). Thermal characterization of the polymers by differential thermal analysis and thermal gravimetric analysis/mass spectroscopy did not disclose any thermal transition to 450°C. Onset of weight loss in air did not occur until over 550°C.     

Synthesis and properties of poly(heteroaryleneethynylene)s consisting of electron‐accepting benzothiadiazole/quinoxaline units and electron‐donating alkyl thiophene units

Low‐band‐gap π‐conjugated polymers composed of π‐excessive thiophene and π‐deficient benzothiadiazole and quinoxaline units were prepared in high yields by a polycondensation method using palladium cross‐coupling reactions of alkylthiophene diacetylenes, 4,7‐dibromo‐2,1,3‐benzothiadiazole, and 5,8‐dibromo‐2,3‐dipyridine‐2‐ylquinoxaline. The copolymers were characterized by NMR, IR, UV, gel permeation chromatography, and elemental analysis. High‐molecular‐weight (weight‐average molecular weight up to 82,600 g/mol), thermostable, soluble, and film‐forming materials were obtained. The polymers were photoluminescent in chloroform and showed metallic luster in the solid state. The absorption and emission in solution and in the solid state of the polymers revealed that the polymers generated a π‐stacked structure in the solid state, and the polymer molecules in the film were ordered. Thin films of poly[3‐dodecylthiophen‐2,5‐diylethynylene‐(benzo[1,2,5]thiadiazole‐4,7‐diyl)ethynylene] ( P‐1 ), poly[3,4‐di dodecylthiophen‐2,5‐diylethynylene‐(benzo[1,2,5]thiadiazole‐4,7‐diyl)ethynylene] ( P‐2 ), poly[3‐dodecylthiophene‐2,5‐diylethynylene‐(2,3‐dipyridine‐2‐ylquinoxaline‐5,8‐diyl)ethynylene] ( P‐3 ), and poly[3,4‐didodecylthiophene‐2,5‐diylethynylene‐(2,3‐dipyridine‐2‐ylquinoxaline‐5,8‐diyl)‐ethynylene] ( P‐4 ) exhibited an optical band gap of ～1.85–2.08 eV. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of the polymers were determined from electrochemical measurements. In the absorption and emission spectra of these polymers in chloroform/methanol mixtures, all the polymers revealed solvatochromic effects, which were related to the formation of aggregates, as confirmed by temperature‐dependence absorption investigations. The absorption spectra of P‐2 and P‐4 at different temperatures also revealed significant effects of the structure on the molecular interactions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6445–6454, 2005     

Aromatic and rigid rod polyelectrolytes based on sulfonated poly(benzobisthiazoles)

Aromatic polyelectrolytes based on sulfonated poly(benzobisthiazoles) (PBTs) have been synthesized by a polycondensation reaction of sulfo-containing aromatic dicarboxylic acids with 2,5-diamino-1,4-benzenedithiol dihydrochloride (DABDT) in freshly prepared polyphosphoric acid (PPA). Several sulfonated PBTs, poly[(benzo[1,2-d:4,5-d′]bisthiazole-2,6-diyl)-2-sulfo-1,4-phenylene] sodium salt (p-sulfo PBT), poly[(benzo[1,2-d:4,5-d′]bisthiazole-2,6-diyl)-5-sulfo-1,3-phenylene] sodium salt (m-sulfo PBT), their copolymers, and poly[(benzo[1,2-d:4,5-d′]bisthiazole-2,6-diyl)-4,6-disulfo-1,3-phenylene] potassium salt (m-disulfo PBT), have been targeted and the polymers obtained characterized by ¹³C-NMR, FT-IR, elemental analysis, thermal analysis, and solution viscosity measurements. Structural analyses confirm the structures of p-sulfo PBT and m-disulfo PBT, but suggest that the sulfonate is cleaved from the chain during synthesis of m-sulfo PBT. m-Disulfo PBT dissolves in water as well as strong acids, while p-sulfo PBT dissolves well in strong acids, certain solvent mixtures containing strong acids, and hot DMSO. TGA indicates that these sulfonated PBTs are thermally stable to over 500°C. Free-standing films of p-sulfo PBT, cast from dilute neutral DMSO solutions, are transparent, tough, and orange in color. Films cast from basic DMSO are also free standing, while being opaque and yellow-green. p-Sulfo PBT was incorporated as the dopant ion in polypyrrole, producing conductive films with conductivities as high as 3 S/cm and electrical anisotropies as high as 10. © 1996 John Wiley & Sons, Inc.     

Polyesters containing bicyclo[2.2.2]octane and bicyclo[3.2.2]nonane rings

Polyesters containing bicyclo[2.2.2]octane and bicyclo[3.2.2]nonane rings are prepared from 1,4-bis(carboethoxy)bicyclo[2.2.2]octane, 1,4-bis(hydroxymethyl)bicyclo[2.2.2]-octane and the 1,5-disubstituted bicyclo[3.2.2]nonane analogs. These polyesters are compared to the related polymers containing 1,4-phenylene and trans-1,4-cyclohexylene rings in terms of their melting point, thermal stabilities and oxidative stabilities. The lower symmetry of the bicyclo[3.2.2]nonane ring produces lower-melting polymers than the other ring systems. The remaining three rings are approximately equivalent in their effect on the melting point of a polymer provided that no more than one bicyclo[2.2.2]octane ring is present per polymer repeat unit. Two such rings produce a highermelting polymer than any other combination. Both the thermal and oxidative stabilities of the polyesters is improved by the presence of the bicyclo rings. This is attributed to the rings providing an approximation of a ladder polymer.     

Synthesis of Poly（p-phenyleneethynylene）s with Crosslinkable End or Side Groups and Its Solid State Structure and Optical Properties Before and after Crosslinking

Two crosslinkable poly(p-phenyleneethynylene)s(PPEs): poly[2,5-di(2'-ethyl-hexyloxy)-1,4-phenylenee-thynylene] with end-capped vinyl(PPE1) and poly[2,5-di(allyloxy)-1,4-phenyleneethynylene-2,5-di(2'-ethyl-hexyloxy)-1,4-phenyleneethynylene](PPE2) were synthesized. Via the thermal addition reactions of vinyl end groups of PPE1 and allyloxy side groups of PPE2, crosslinked polymers C-PPE1 and C-PPE2 were obtained, respectively. The two polymers were characterized by wide-angle X-ray diffraction(WXRD), ultravio...     

Novel aromatic polyhydrazides and poly(amide-hydrazide)s based on “multiring” flexible dicarboxylic acids

Two flexible dicarboxylic acid monomers, 4,4′-[isopropylidenebis(1,4-phenylene)dioxy]dibenzoic acid ( 1 ) and 4,4′-[hexafluoroisopropylidenebis(1,4-phenylene)-dioxy]dibenzoic acid ( 3 ), were synthesized from readily available compounds in two steps in high yields. High molecular-weight polyhydrazides and poly(amide-hydra-zide)s were directly prepared from dicarboxylic acids 1 and 3 with terephthalic dihydrazide ( 5 ), isophthalic dihydrazide ( 6 ), and p-aminobenzhydrazide ( 7 ) by the phosphorylation reaction by means of diphenyl phosphite (DPP) and pyridine in N-methyl-2-pyrrolidone (NMP)/LiCl, or prepared from the diacyl chlorides of 1 and 3 with the hydrazide monomers 5–7 by the low-temperature solution polycondensation in NMP/LiCl. Less favorable results were obtained when using triphenyl phosphite (TPP) instead of DPP in the direct polycondensation reactions. Except for those derived from terephthalic dihydrazide, the resulting polyhydrazides and poly(amide-hydrazide)s could be cast into colorless, flexible, and tough films with good tensile strengths. All the hydrazide polymers and copolymers are amorphous in nature and are readily soluble in various polar solvents such as NMP and dimethyl sulfoxide (DMSO). Their T_gs were recorded in the range of 162–198°C and could be thermally cyclodehydrated into the corresponding polyoxadiazoles and poly(amide-oxadiazole)s approximately in the region of 300–380°C, as evidenced by the DSC thermograms. The oxadiazole polymers and copolymers showed a dramatically decreased solubility and higher T_g when compared to their respective hydrazide prepolymers. They exhibited T_gs of 190–216°C and were stable up to 450°C in air or nitrogen. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1847–1854, 1998     

Synthesis and characterization of luminescent copolymers containing iminodibenzyl and divinylbenzene chromophores

New conjugated copolymers containing alternating N‐hexyl‐3,8‐iminodibenzyl and divinylbenzene chromophores {poly(N‐hexyl‐3,8‐iminodibenzyl‐1,2‐ethenylene‐2,5‐dihexyloxy‐1,4‐phenylene‐1,2‐ethenylene) ( P1 ) and poly[N‐hexyl‐3,8‐iminodibenzyl‐2,5‐bis(hexyloxy)cyanoterephthalidene] ( P2 )} were synthesized according to Wittig and Knoevenagel polymerization. A copolymer containing alternating carbazole and divinylbenzene derivatives {poly[9‐(2‐ethylhexyl)‐3,6‐carbazole‐1,2‐ethenylene‐2,5‐dihexyloxy‐1,4‐phenylene‐1,2‐ethenylene] ( P3 )} was also synthesized for comparison. The copolymers were soluble in common organic solvents such as tetrahydrofuran and toluene. Absorption and photoluminescence measurements revealed that cyano substitution at the vinylene moiety in P2 brought about a significant bathochromic shift and led to an electroluminescence color change from green to orange. The band edge energies of the copolymers were estimated from cyclic voltammograms and optical band gaps. P1 and P3 showed similar highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels, indicating that the electron‐donating abilities of the iminodibenzyl and carbazole chromophores were comparable. However, compared with those of P1 and P3 , the HOMO and LUMO levels of P2 were greatly reduced because of conjugating and electron‐withdrawing CN groups. The threshold electric field of an Al/ P1 /ITO glass single‐layer light‐emitting diode was approximately 10 × 10⁵ V/cm, whereas those for P2 and P3 were 7.5 and 16 × 10⁵ V/cm, respectively. The electroluminescence emission maxima of P1–P3 were 498, 514, and 559 nm, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3847–3857, 2002     

Synthesis and photochemical property of polymers with pendant donor–acceptor-type norbornadiene moieties

The donor–acceptor-type norbornadiene (D–A NBD) 1,4,5,6-tetramethyl-3-phenyl-2,5-NBD-2-carboxylic acid was prepared by the Diels–Alder reaction of methyl 3-phenylprop-2-ynoate with 1,2,3,4-tetramethyl-1,3-cyclopentadiene. 1,4,5,6,7-Pentamethyl-3-phenyl-2,5-NBD-2-carboxylic acid was also synthesized in the same way. Styrene-type polymers with pendant D–A NBD moieties were prepared with a 100% degree of substitution (DS) by the reaction of D–A NBD carboxylic acids with poly[(p-chloromethyl)styrene] with 1,8-diazabicyclo[5.4.0]undecene-7 in dimethyl sulfoxide at 70 °C for 6 h. In the reaction of D–A NBD carboxylic acids with poly(2-chloroethyl vinyl ether), the DSs were about 60%. The photochemical valence isomerizations of all the NBD polymers proceeded smoothly with UV irradiation in tetrahydrofuran solutions and in the film state. In addition, the rate of the photochemical reaction of the NBD polymers increased efficiently by the addition of 4,4′-bis(diethylamino)benzophenone as a photosensitizer in a film state. The stored thermal energy of the irradiated polymers was also evaluated by differential scanning calorimetry to be 55–74 kJ/mol. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1764–1773, 2001     

苯并二噁唑系列聚合物的合成及表征

以4,6-二氨基-1,3-苯二酚盐酸盐为原料,分别和对苯二甲酸、1,4-萘二甲酸、2,6-萘二甲酸、2,5-噻吩二甲酸、4,4-′(1,2-二苯基乙烯)二甲酸在多聚磷酸介质中反应,合成单环的聚(1,4-亚苯基)苯并二噁唑(PBO)、稠环的聚(1,4-亚萘基)苯并二噁唑(1,4-PNBO)和聚(2,6-亚萘基)苯并二噁唑(2,6-PNBO)、杂环的聚(2,5-亚噻吩基)苯并二噁唑(PTBO)及含有两个苯环的聚-4,4′-亚(1,2-二苯乙烯基)苯并二噁唑(4,4′-PDPEBO).采用傅立叶红外光谱、热重分析、元素分析、特性黏数分析对系列聚合物进行了表征.研究结果表明PBO、1,4-PNBO、4,4-′PDPEBO、2,6-PNBO和PTBO 5种聚合物的耐热性能依次降低,特性黏数依次为25.40、16.76、20.63、15.38和14.63 dL/g.     

Synthesis and characterization of aromatic poly(ether sulfone imide)s derived from sulfonyl bis(ether anhydride)s and aromatic diamines

Two sulfonyl group-containing bis(ether anhydride)s, 4,4′-[sulfonylbis(1,4-phenylene)dioxy]diphthalic anhydride ( IV ) and 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenylene)dioxy]diphthalic anhydride (Me- IV ), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of the bisphenolate ions of 4,4′-sulfonyldiphenol and 4,4′-sulfonylbis(2,6-dimethylphenol) with 4-nitrophthalonitrile in N,N-dimethylformamide (DMF). High-molar-mass aromatic poly(ether sulfone imide)s were synthesized via a conventional two-stage procedure from the bis(ether anhydride)s and various aromatic diamines. The inherent viscosities of the intermediate poly(ether sulfone amic acid)s were in the ranges of 0.30–0.47 dL/g for those from IV and 0.64–1.34 dL/g for those from Me- IV. After thermal imidization, the resulting two series of poly(ether sulfone imide)s had inherent viscosities of 0.25–0.49 and 0.39–1.19 dL/g, respectively. Most of the polyimides showed distinct glass transitions on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (T_g) were recorded between 223–253 and 252–288°C, respectively. The results of thermogravimetry (TG) revealed that all the poly(ether sulfone imide)s showed no significant weight loss before 400°C. The methyl-substituted polymers showed higher T_g's but lower initial decomposition temperatures and less solubility compared to the corresponding unsubstituted polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1649–1656, 1998