Synthesis and characterization of novel semiaromatic copolyamides bearing both polar hydroxyl and unsaturated allyl substituents

A series of novel semiaromatic (co)polyamides, poly(octylene terephthalamide)-ran-poly[octylene 2,5-bis(allyloxy)terephthalamide] (APA8T-x, x represents the molar fraction of allyloxy containing structure unit), were prepared via the interfacial polymerization of 1,8-diaminooctane, terephthaloyl chloride, and 2,5-bis(allyloxy)terephthaloyl chloride. The polymerization conditions were optimized in terms of the yields and the molecular weights of the resultant polymers. These polymers were converted to the target macromolecules, poly(octylene terephthalamide)-ran-poly[octylene (2,5-dihydroxy-3,6-diallyl)terephthalamide] (CRPA8T-x), through solid state Claisen rearrangement reaction, as characterized by ¹H NMR and FT-IR spectroscopies. While APA8T-x was only soluble in very limited solvents, the solubility of CRPA8T-x in polar solvents improved remarkably, especially for those with high counit content. Due to the polarity of hydroxyl group, CRPA8T-x showed an improved hydrophilicity than APA8T-x. The treatment of aramid fibers with CRPA8T-x, as sizing agents, enhanced obviously their interfacial adhesion toward epoxy resin. The fibers sized with 0.5 wt% CRPA8T-75 solution in the mixture of 1,1,2,2-tetrachloroethane and phenol (40:60, w/w) exhibited a maximum increase of 60% in interfacial shear strength than the naked fibers. The easy preparation and the facility for the further modification through the dual functional substituents may greatly widen the application of semiaromatic polyamides. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 690–698     

The effect of hydrogen bonding on the physical and mechanical properties of rigid‐rod polymers

The idea of competing effects between intramolecular and intermolecular hydrogen bonding was investigated. Results indicate that the formation of one type of hydrogen bond does not preclude the formation of the other. The strength of the intermolecular association was measured by ab initio calculations for several polymer systems, including methyl pendant poly(p‐phenylene benzobisimidazole) and poly‐{2,6‐diimidazo[4,5‐b:4′5′‐e]pyridinylene‐1,4(2,5‐dihydroxy)phenylene} (PIPD). Fibers with strong intermolecular association have high compressive strength and torsional modulus. The influence of intermolecular hydrogen bonding on torsional modulus is discussed in light of the transverse texture present in poly(p‐phenylene terephthalamide) and some other high‐performance fibers. Enhanced intermolecular interaction not only influences the aforementioned properties but also results in higher fiber density. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 3053–3061, 2000     

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     

Preparation and properties of a new aromatic polyamide with an ethoxycarbonyl pendant group: Poly(4,4′‐diamino‐2′‐ethoxycarbonyl‐benzanilide terephthalamide)

A new aromatic polyamide containing a pendant ethoxycarbonyl group was successfully synthesized from the reaction between 4,4′‐diamino‐2′‐ethoxycarbonylbenzanilide and terephthaloyl chloride. The new polymer was soluble in organic solvents such as N‐methyl‐2‐pyrrolidone and dimethylacetamide, and a tough and transparent film was cast from the polymer solution with viscosities ranging from 2.6 to 5.6 dL/g. When the polymer film was heat‐treated at a temperature greater than 300 °C, a cyclization reaction occurred between the ethoxycarbonyl group and the adjacent amide bond to form a benzoxazinone unit in the polymer backbone. The thermal decomposition onset temperature of the cyclized film was about 523 °C, which was somewhat lower than that of poly(p‐phenylene terephthalamide) (PPTA; 566 °C); however, the decomposition rate was slower than that of PPTA to yield a higher char residue. The dispersion temperature of the uncyclized poly(4,4′‐diamino‐2′‐ethoxycarbonylbenzanilide terephthalamide) (PDEBTA) was about 340 °C, whereas that of the cyclized PDEBTA was not clear. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 936–942, 2000     

Protein–induced aggregation of fluorescent conjugated polyelectrolytes with sulfonate groups: Synthesis and its sensing application

Anionically charged fluorescent conjugated polyelectrolytes of poly{[4,7‐(2,1,3‐benzothiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} ( P1 ) and poly{[4,7‐(bis(thiophen‐2‐yl)benzo‐2,1,3‐thiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} ( P2 ) were synthesized by Suzuki crosscoupling polymerization in the presence of a palladium catalyst. The conjugated polyelectrolytes with sulfonate groups, as efficient signal amplifying reporters, were carefully designed to be soluble in water over the entire pH range examined and interact with proteins through intermolecular forces. The polymers exhibited blue emission in aqueous solutions but green or red emission in solid form depending on the conjugation length due to intermolecular exciton migration. The anionic conjugated polymers exhibited blue‐to‐green or blue‐to‐red changes in fluorescence upon exposure to charged proteins, indicating that the polymers have potential applications in fluorescent array systems for protein. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Preparation and physical properties of poly(4,4′‐diamino‐3′‐carbamoylbenzanilide terephthalamide) and poly(4,4′‐diamino‐3′‐carbamoylbenzanilide isophthalamide) films

To prepare thermally stable and high‐performance polymeric films, new solvent‐soluble aromatic polyamides with a carbamoyl pendant group, namely poly(4,4′‐diamino‐3′‐carbamoylbenzanilide terephthalamide) (p‐PDCBTA) and poly(4,4′‐diamino‐3′‐carbamoylbenzanilide isophthalamide) (m‐PDCBTA), were synthesized. The polymers were cyclized at around 200 to 350 °C to form quinazolone and benzoxazinone units along the polymer backbone. The decomposition onset temperatures of the cyclized m‐ and p‐PDCBTAs were 457 and 524 °C, respectively, lower than that of poly(p‐phenylene terephthalamide) (566 °C). For the p‐PDCBTA film drawn by 40% and heat‐treated, the tensile strength and Young's modulus were 421 MPa and 16.4 GPa, respectively. The film cyclized at 350 °C showed a storage modulus (E′) of 1 × 10¹¹ dyne/cm² (10 GPa) over the temperature range of room temperature to 400 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 775–780, 2000     

Highly luminescent diyne (?CC?CC?) containing hybrid polyphenyleneethynylene/poly(p‐phenylenevinylene) polymer: Synthesis and characterization

Luminophoric dialdehyde 1,4‐bis[4‐formylphenylethynyl‐(2,5‐dioctadecyloxyphenyl)‐buta‐1,3‐diyne] ( 4 ) enables the synthesis of diyne‐containing hybrid polyphenyleneethynylene/poly(p‐phenylenevinylene) polymer poly[1,4‐phenylene‐ethynylene‐1,4‐(2,5‐dioctadecyloxy)phenylene‐butadi‐1,3‐ynylene‐1,4‐(2,5‐dioctadecyloxy)phenylene‐ethynylene‐1,4‐phenylene‐ethene‐1,2‐diyl‐1,4‐(2,5‐dioctadecyloxy)phenylene‐ethene‐1,2‐diyl] ( 7 ) with a well‐defined general structure (? Ph? C?C? Ar? C?C? C?C? Ar? C?C? Ph? CH?CH? Ar? CH?CH? )_n, which was confirmed by NMR and infrared spectroscopy. The highly luminescent material is thermostable, soluble in usual organic solvents through the grafting of octadecyloxy side groups, and can be processed into transparent films. With the aim to investigate the effect of ? C?C? C?C? in the photophysical behavior of 7 , a comparison of the photophysics of monomers 3 [1,4‐bis(4‐formylphenylethynyl)‐2,5‐dioctadecyloxybenzene] and 4 and subsequently of their respective polymers 6 and 7 has been carried out. Similar photophysical behaviors for 6 (poly[1,4‐phenylenethynylene‐1,4‐(2,5‐dioctadecyloxyphenylene)ethene‐1,2‐diyl]) and 7 were observed in dilute CHCl₃ solution as a result of an identical chromophore system responsible for the absorption (λ_a = 448 nm) and emission (λ_f = 490 nm) in both compounds. The increased planarization and enhanced rigidity of the conjugated backbone in the solid state at room temperature as well as in frozen dilute tetrahydrofuran solution at 77 K cause the bathochromic shift of the absorption and emission spectra. The large octadecyloxy side chains obviously limit strong π‐π interchain interactions in the solid films, which explains the high fluorescence quantum yields of 35 and 52% obtained for 6 and 7 , respectively. The energetically arduous migration of the π electron through the diyne units not only requires a higher threshold voltage for the detection of photoconductivity in 7 but could possibly limit radiationless deactivation channels of the exciton, which explains the approximate 20% fluorescence quantum yields difference between 6 and 7 in the solid state. The electron‐withdrawing effect of the triple bonds confer both 6 and 7 with a good electron‐accepting property (E^ox = 1.39 V vs Ag/AgCl) if used in light‐emitting diode devices. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2670–2679, 2002     

Palladium‐catalyzed three‐component coupling polycondensation of aromatic diiodide,aromatic bis(boronic acid propanediol ester), and norbornadiene: A new route for poly(p‐phenylene vinylene)

A novel synthetic method for soluble precursor polymers of poly(p‐phenylene vinylene) (PPV) derivatives by the palladium‐catalyzed three‐component coupling polycondensation of aromatic diiodides, aromatic bis(boronic acid) derivatives, and norbornadiene is described. For example, the polymerization of 1,4‐diiodo‐2,5‐dioctyloxybenzene, benzene‐1,4‐bis(boronic acid propanediol ester), and norbornadiene at 100 °C for 3 days provided a polymer consisting of the three monomer units in a 97% yield (number‐average molecular weight = 3100, weight‐average molecular weight/number‐average molecular weight = 1.37). A derivative of PPV was produced smoothly by the retro Diels–Alder reaction of the polymer both in a dodecyloxybenzene solution and in a film at 200 °C in vacuo. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3403–3410, 2005     

Green‐emitting poly[(1,3‐phenylenevinylene)‐alt‐ (1,4‐phenylenevinylene)]s: Effect of the substitution patterns on the optical properties

Green‐emitting substituted poly[(2‐hexyloxy‐5‐methyl‐1,3‐phenylenevinylene)‐alt‐(2,5‐dihexyloxy‐1,4‐phenylenevinylene)]s ( 6 ) were synthesized via the Wittig–Horner reaction. The polymers were yellow resins with molecular weights of 10,600. The ultraviolet–visible (UV–vis) absorption of 6 (λ_max = 332 or 415 nm) was about 30 nm redshifted from that of poly[(2‐hexyloxy‐5‐methyl‐1,3‐phenylenevinylene)‐alt‐(1,4‐phenylenevinylene)] ( 2 ) but was only 5 nm redshifted with respect to that of poly[(1,3‐phenylenevinylene)‐alt‐(2,5‐dihexyloxy‐1,4‐phenylenevinylene)] ( 1 ). A comparison of the optical properties of 1 , 2 , and 6 showed that substitution on m‐ or p‐phenylene could slightly affect their energy gap and luminescence efficiency, thereby fine‐tuning the optical properties of the poly[(m‐phenylene vinylene)‐alt‐(p‐phenylene vinylene)] materials. The vibronic structures were assigned with the aid of low‐temperature UV–vis and fluorescence spectroscopy. Light‐emitting‐diode devices with 6 produced a green electroluminescence output (emission λ_max ～ 533 nm) with an external quantum efficiency of 0.32%. Substitution at m‐phenylene appeared to be effective in perturbing the charge‐injection process in LED devices. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1820–1829, 2004     

The suzuki–heck polymerization as a tool for the straightforward obtainment of poly(fluorenylene‐vinylene) sensitizers for dye‐sensitized solar cells

This article describes the synthesis and properties of the first poly(arylene‐vinylene)‐based sensitizers for application in dye‐sensitized solar cells (DSSC). The polymers were prepared by the Suzuki–Heck copolymerization of potassium vinyltrifluoroborate (PVTB) with a mixture of dibromoaryl comonomers designed to obtain macromolecules able to bind onto the photoelectrode by means of carboxyphenylene units. The copolymerization reactions were carried out in the presence of an excess of PVTB to lower the molecular weights of the polymers, which were obtained as soluble materials. The polymers poly[(9,9‐didodecyl‐2,7‐fluorenylene)‐vinylene‐co‐(carboxy‐2,5‐phenylene)‐vinylene] ( P1 ), poly[(9,9‐didodecyl‐2,7‐fluorenylene)‐vinylene‐co‐(carboxy‐2,5‐phenylene)‐vinylene‐co‐(4,7‐benzothiadiazolylene)‐vinylene] ( P2 ), and poly[(9,9‐didodecyl‐2,7‐fluorenylene)‐vinylene‐co‐(carboxy‐2,5‐phenylene)‐vinylene‐co‐2,5‐thienylene‐vinylene] ( P3 ) were used in DSSC devices, obtaining conversion efficiencies up to 0.88% ( P3 ). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Spontaneous formation of hierarchical proton‐conductive structures in sulfonated poly(p‐phenylene terephthalamide) copolymer films

Two partially sulfonated copolymers of poly(p‐phenylene terephthalamide) were studied; the sulfonated diamine to nonsulfonated diamine ratios were x = 1 and x = 2. Polymer solutions in water demonstrated lyotropic liquid‐crystalline behavior, with the critical concentration for nematic phase formation being around 0.7 wt %. Films of these copolymers could be considered for fuel‐cell applications. The in‐plane proton conductivities were of the order of 10^?3 to 10^?2 S cm^?1 between 20 and 90 °C. Increasing the sulfonation level resulted in a more conductive material. Spontaneous alignment of the polymer occurred during film formation, as revealed by X‐ray diffraction. Scattering along the polymer backbone was observed perpendicular to the film, implying that the polymer chains were homeotropically aligned with respect to the film. The average degree of alignment was determined to be 0.66 and 0.77 for x = 1 and x = 2, respectively. Evidence of secondary layering within the plane of the film was seen in SEM images. These layers could provide a pathway for proton conduction to occur within the plane of the film. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 666–676, 2007     

Synthesis,characterization, and structure–property investigation of conformationally rigid regioisomers of poly(p‐phenylene ethynylene)s

A series of rigid poly(p‐phenylene ethynylene)s ( PPE1 – PPE4 ) with biphenyl‐ ( M1–M3 ) and phenyl‐ ( M4 ) side groups is prepared from appropriately functionalized monomers. Herein, the solution and solid state absorption studies show the polymers have adopted twisted and rigid conformations, as supported by deep HOMO energy levels (?5.76 to ?5.81 eV). The absorption maxima of PPE1–PPE3 are shifted to shorter wavelength (λ_max = 375–381 nm) as compared to linear poly(p‐phenylene ethynylene)s (446 nm), implying a nonplanar conformation. The self‐assembly of polymers into fibers is examined using scanning electron microscopy. The fibers are not observed in PPE4 with short phenyl side group, suggesting the important role of the interplay between rigidity, position, and size of the side chains toward the formation of fibers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3652–3662     

Stress behaviors and thermal properties of polyimide thin films depending on the different curing process

The effect of high boiling point solvent on the residual stress behaviors of semiflexible structure poly(4,4′‐oxydiphenylene pyromellitimide) (PMDA‐ODA) and pseudo‐rodlike poly(p‐phenylene biphenyltetracarboximide) (BPDA‐PDA) polyimide was investigated. As a solvent, a mixed solution of 20 wt % cyclohexyl‐2‐pyrrolidone (CHP; bp = 307 °C) and 80 wt % n‐methyl‐2‐pyrrolidone (NMP; bp = 202 °C) was used. The effects of solvent system and imidizing history on the morphological structure, as well as residual stress, were significantly high in the BPDA‐PDA having high chain rigidity, but relatively low in the semiflexible PMDA‐ODA with low chain rigidity. In addition, rapidly cured films prepared from PAA (NMP/CHP) showed higher residual stress and a lower degree of molecular anisotropy than slowly cured film imidized from PAA (NMP). This was induced by high chain mobility in polyimide thin films prepared from PAA (NMP/CHP) during the thermal cure process. Therefore, molecular anisotropy, depending on the solvent system and imidizing history, might be one of the important factors leading to low residual stress in polyimide thin films. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2879–2890, 2000     

Synthesis of new poly(amide imide)s with (n‐alkyloxy)phenyloxy side branches

Two series of new poly(amide imide)s having (n‐alkyoxy)phenyloxy side branches with various lengths, poly{p‐phenyleneiminoterephthaloylimino‐p‐phenylene[3,6‐di(n‐alkyloxy)phenyloxy]pyromellitimide}s ( PC _m TA s, m = 4, 8, 12) and poly{p‐phenyleneiminosebacoylimino‐p‐phenylene[3,6‐di(n‐alkyloxy)‐phenyloxy]‐ pyromellitimide}s ( PC _m SeA s, m = 4, 8, 12), were prepared by condensation of terephthalamide‐N,N′‐4,4′‐dianiline ( TA ) and sebacamide‐N,N′‐4,4′‐dianiline ( SeA ) with 3,6‐di[4‐(n‐alkyloxy)phenyloxy]pyromellitic dianhydrides , respectively. The inherent viscosities of the polymers were in the 0.82–1.20 dL/g range. The polymers were highly soluble in N‐methylpyrolidinone (NMP), even at room temperature and soluble in other polar aprotic solvents on heating. The PC _m TA s, which have aromatic backbones, were thermally more stable (431–442 °C) than the PC _m SeA s, which have an octamethylene unit in the main chain (407–409 °C). Degradation of weight up to 900 °C corresponded with the loss of side chain contents. The PC _m TA s exhibited no phase transition, whereas two endothermic peaks were observed for each of the PC _m SeA s. Wide‐angle X‐ray diffractometer investigations revealed that both polymers are amorphous and the n‐alkyloxy side chains are present in a layered structure. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3818–3825, 2001     

Preparation of aromatic copolyamides containing regularly placed 1,6-hexamethylenediamine units

Copolyamides based on poly(m-phenylene isophthalamide) and poly-(p-phenylene terephthalamide), to which 1,6-diaminohexane units were regularly inserted every 3 or 5 phenylene monomer units, were synthesized. The copolymers were obtained by condensation of individually prepared diamino- and dicarboxylic-building blocks via the Yamazaki–;Higashi reaction. Solubility of the copolyamides are discussed in relation with the structure. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2379–2386, 1997     

Novel route to poly(p‐phenylene vinylene) polymers

Poly(p‐phenylene vinylene) (PPV), poly(2,5‐dioctyl‐p‐phenylene vinylene) (PDOPPV), and poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐p‐phenylene vinylene] (MEHPPV) were synthesized by a liquid–solid two‐phase reaction. The liquid phase was tetrahydrofuran containing 1,4‐bis(bromomethyl)benzene, 1,4‐bis(chloromethyl)‐2,5‐dioctylbenzene, or 1,4‐bis(chloromethyl)‐2‐methoxyl‐5‐(2′‐ethylhexyloxy)benzene as the monomer and a certain amount of tetrabutylammonium bromide as a phase‐transfer catalyst. The solid phase consisted of potassium hydroxide particles with diameters smaller than 2 mm. The experimental results demonstrated that the reaction conversions of PPV and PDOPPV were fairly high (～65%), but the conversion of MEHPPV was only 45%. Moreover, gelation was found in the polymerization processes. As a result, PPV was insoluble and PDOPPV and MEHPPV were partially soluble in the usual organic solvents, such as tetrahydrofuran and chloroform. Soluble PDOPPV and MEHPPV were obtained with chloromethylbenzene or bromomethylbenzene as a retardant regent. The molar mass of soluble PDOPPV was measured to be 2 × 10⁴ g mol^?1, and that of MEHPPV was 6 × 10⁴ g mol^?1. A thin, compact film of MEHPPV was formed via spin coating, and it emitted a yellow light. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 449–455, 2003     

A facile strategy for synthesis of α,α′‐heterobifunctionalized poly (ε‐caprolactones) and poly (methyl methacrylate)s containing “clickable” aldehyde and allyloxy functional groups using initiator approach

Two new initiators, namely, 4‐(4‐(2‐(4‐(allyloxy) phenyl)‐5‐hydroxypentane 2‐yl) phenoxy)benzaldehyde and 4‐(4‐(allyloxy) phenyl)‐4‐(4‐(4‐formylphenoxy) phenyl) pentyl 2‐bromo‐2‐methyl propanoate containing “clickable” hetero‐functionalities namely aldehyde and allyloxy were synthesized starting from commercially available 4,4′‐bis(4‐hydroxyphenyl) pentanoic acid. These initiators were utilized, respectively, for ring opening polymerization of ε‐caprolactone and atom transfer radical polymerization of methyl methacrylate. Well‐defined α‐aldehyde, α′‐allyloxy heterobifunctionalized poly(ε‐caprolactones) (M_n,GPC: 5900–29,000, PDI: 1.26–1.43) and poly(methyl methacrylate)s (M_n,GPC: 5300–28800, PDI: 1.19–1.25) were synthesized. The kinetic study of methyl methacrylate polymerization demonstrated controlled polymerization behavior. The presence of aldehyde and allyloxy functionality on polymers was confirmed by ¹H NMR spectroscopy. Aldehyde‐aminooxy and thiol‐ene metal‐free double click strategy was used to demonstrate reactivity of functional groups on polymers. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Synthesis of three new 1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl) pyrrole‐based donor polymers and their bulk heterojunction solar cell applications

A series of three new 1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole‐based polymers such as poly[1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole] ( PTPT ), poly[1,4‐(2,5‐bis(octyloxy)phenylene)‐alt‐5,5'‐(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole)] ( PPTPT ), and poly[2,5‐(3‐octylthiophene)‐alt‐5,5'‐(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole)] ( PTTPT ) were synthesized and characterized. The new polymers were readily soluble in common organic solvents and the thermogravimetric analysis showed that the three polymers are thermally stable with the 5% degradation temperature >379 °C. The absorption maxima of the polymers were 478, 483, and 485 nm in thin film and the optical band gaps calculated from the onset wavelength of the optical absorption were 2.15, 2.20, and 2.13 eV, respectively. Each of the polymers was investigated as an electron donor blending with PC₇₀BM as an electron acceptor in bulk heterojunction (BHJ) solar cells. BHJ solar cells were fabricated in ITO/PEDOT:PSS/polymer:PC₇₀BM/TiO_x/Al configurations. The BHJ solar cell with PPTPT :PC₇₀BM (1:5 wt %) showed the power conversion efficiency (PCE) of 1.35% (J_sc = 7.41 mA/cm², V_oc = 0.56 V, FF = 33%), measured using AM 1.5G solar simulator at 100 mW/cm² light illumination. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and luminescence of yellow/orange‐emitting poly[tris(2,5‐dihexyloxy‐1,4‐phenylenevinylene)‐ alt‐(1,3‐phenylenevinylene)]s

Soluble yellow/orange‐emitting poly[tris(2,5‐dihexyloxy‐1,4‐phenylenevinylene)‐alt‐(1,3‐phenylenevinylene)] derivatives ( 6 ) were synthesized and characterized. These polymers contained oligo(p‐phenylene vinylene) chromophores of equal conjugation length, which were jointed via a common m‐phenylene unit. An optical comparison of 6 and its model compound ( 8 ) at room temperature and low temperatures revealed the similarity in their absorption and fluorescence band structures. The vibronic band structure of 6 was assigned with the aid of the spectroscopic data for 8 at the low temperatures. 6 was electroluminescent and had an emission maximum wavelength at approximately 565 nm. With the device indium tin oxide/PEDOT/ 6 /Ca configuration, the polymer exhibited an external quantum efficiency as high as 0.25%. Simple substitution on m‐phenylene of 6 raised the electroluminescence output by a factor of about 10. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5853–5862, 2004     

Syntheses and X-Ray Structures for Model Compounds of a Pyrimidinediyl-Based Rigid-Rod Aromatic Polyamide

A variety of model compounds for the pyrimidinediyl-based rigid-rod polyamide poly[imino-(pyrimidine-2,5-diyl)-imino-tetraphthaloyl] (PPYMT) was prepared, in order to compare their conformations to several model compounds of the related, fully aromatic polymer poly(p-phenyleneterephthalamide) (PPTA). In particular, the structures of N-(2-pyrimidyl)benzamide (PYMB) and its complexed form bis[(N-pyrimidin-2-yl)benzamide]nickel(II) dichloride (NiPYMB) were determined by X-ray diffraction. The molecular packing in these crystals provides us with a model for the possible ‘cross-linking’ of PPYMT fibers. The structures of the trimer model compounds N,N′ -bis(2-pyrimidyl)terephthalamide (PYTA) and N,N′ -bis(benzoyl)-2,5-diaminopyrimidine (BDAP) yield information about the conformation of PPYMT chains and are compared to analogous model compounds of PPTA.