共查询到20条相似文献,搜索用时 15 毫秒
1.
Shawn Jenkins Karl I. Jacob Satish Kumar 《Journal of Polymer Science.Polymer Physics》2000,38(23):3053-3061
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 相似文献
2.
《Journal of polymer science. Part A, Polymer chemistry》2018,56(15):1721-1729
Film‐forming polymers containing ionic groups have attracted considerable attention as emerging materials for gas separation applications. The aim of this article was to synthesize new film‐forming polyimides containing imidazolium groups (PI‐IMs) and establish their structure–performance relationship. In this context, a new aromatic diamine, namely, N1‐(4‐aminophenyl)‐N1‐(4‐(2‐phenyl‐1H‐imidazol‐1‐yl)phenyl)benzene‐1,4‐diamine (ImTPADA), was synthesized and polycondensed with three aromatic dianhydrides, namely, 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, 4,4‐(4,4‐isopropylidenediphenoxy) bis(phthalic anhydride), and 4,4′‐oxydiphthalic anhydride to form the corresponding polyimides containing pendent 2‐phenylimidazole groups (PI‐IEs). Next, PI‐IMs were prepared by N‐quaternization of pendent 2‐phenylimidazole groups present in PI‐6FDA using methyl iodide followed by anion exchange with bis(trifluoromethane)sulfonimide lithium salt (LiTf2N). PI‐IEs and PI‐IMs exhibited reasonably high molecular weights, amorphous nature, good solubility, and could be cast into self‐standing films from their DMAc solutions. Thermogravimetric analysis showed that 10% weight loss temperature of PI‐IEs and PI‐IMs were in the range 545–475 °C and 303–306 °C, respectively. Gas permeability analysis of films of PI‐IEs and PI‐IMs was investigated by variable‐volume method and it was observed that incorporation of ionic groups into PI‐6FDA resulted in increased permeability while maintaining selectivity. In particular, polymer bearing Tf2N− anion exhibited high CO2 permeability (33.3 Barr) and high selectivity for CO2/CH4 (41.1) and CO2/N2 (35.4). © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1721–1729 相似文献
3.
S. L. Liu M. L. Chng T. S. Chung K. Goto S. Tamai K. P. Pramoda Y. J. Tong 《Journal of Polymer Science.Polymer Physics》2004,42(14):2769-2779
A series of indan‐containing polyimides were synthesized, and their gas‐permeation behavior was characterized. The four polyimides used in this study were synthesized from an indan‐containing diamine [5,7‐diamino‐1,1,4,6‐tetramethylindan (DAI)] with four dianhydrides [3,3′4,4′‐benzophenone tetracarboxylic dianhydride (BTDA), 3,3′4,4′‐oxydiphthalic dianhydride (ODPA), (3,3′4,4′‐biphenyl tetracarboxylic dianhydride (BPDA), and 2,2′‐bis(3,4′‐dicarboxyphenyl) hexafluoropropane dianhydride (6FDA)]. The gas‐permeability coefficients of these four polyimides changed in the following order: DAI–BTDA < DAI–ODPA < DAI–BPDA < DAI–6FDA. This was consistent with the increasing order of the fraction of free volume (FFV). Moreover, the gas‐permeability coefficients were almost doubled from DAI–ODPA to DAI–BPDA and from DAI–BPDA to DAI–6FDA, although the FFV differences between the two polyimides were very small. The gas permeability and diffusivity of these indan‐containing polyimides increased with temperature, whereas the permselectivity and diffusion selectivity decreased. The activation energies for the permeation and diffusion of O2, N2, CH4, and CO2 were estimated. In comparison with the gas‐permeation behavior of other indan‐containing polymers, for these polyimides, very good gas‐permeation performance was found, that is, high gas‐permeability coefficients and reasonably high permselectivity. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2769–2779, 2004 相似文献
4.
Li Juan Cao An Yong Li Li Xu Ying Zhang 《International journal of quantum chemistry》2012,112(2):498-508
Density functional method B3LYP plus the AUG‐cc‐pVDZ and AUG‐cc‐pVTZ basis sets is used to investigate ring normal modes of halogen‐substituted pyridines involved in the N ··· H? X H‐bonds with HX (X = F, Cl). The results demonstrated that the formation of hydrogen bond leads to an increase in the frequencies of the ring breathing mode v1, the N‐para‐C stretching mode v6a and the meta‐CC stretching mode v8a, whereas there is no change in the triangle mode v12 for free pyridine and a smaller blue shift for substituted pyridines. There is a strong coupling between the C? Y stretching vibration and the triangle mode (ortho‐ and para‐substituted) or the breathing mode (meta‐substituted) in substituted pyridines, which leads to the frequency decrease in the triangle or breathing modes. The natural bond orbital analysis suggests that electrostatic interaction and charge transfer caused by the intermolecular and intramolecular hyperconjugations are the origin of the frequency blue shift in the ring stretching modes. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
5.
Novel co‐polymerization polyimide (PI) fibers based on 4,4′‐oxydianiline (ODA)‐pyromellitic dianhydride (PMDA) were prepared. 2‐(4‐Aminophenyl)‐5‐aminobenzimidazole (PABZ) containing the N? H group was introduced into the structure of the fibers as the proton donor. The results of Fourier transform infrared (FTIR) and dynamic mechanical analysis (DMA) showed that hydrogen bonding occured between the N? H group and chains, which strongly enhanced interchain interaction. This hydrogen bonding interaction increased the tensile strength and initial modulus of the PI fibers up to 2.5 times and 26 times, respectively, compared to those of homo‐PI PMDA‐ODA fibers with no hydrogen‐bonding interaction because of the absence of proton donors after the imidization process. In the mean time, glass transition temperature (Tg) of the modified PI fibers was found to be 410–440°C, which was higher than that of the homo‐PI PMDA‐ODA fibers. From the result, a novel access to molecular design and manufacture of high performance PI fibers with good properties could be provided. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
A series of rigid‐rod polyamides and polyimides containing p‐terphenyl or p‐quinquephenyl moieties in backbone as well as naphthyl pendent groups were synthesized from two new aromatic diamines. The polymers were characterized by inherent viscosity, elemental analysis, FT‐IR, 1H‐NMR, 13C‐NMR, X‐ray, differential scanning calorimetry (DSC), thermomechanical analysis (TMA), thermal gravimetric analysis (TGA), isothermal gravimetric analysis, and moisture absorption. All polymers were amorphous and displayed Tg values at 304–337°C. Polyamides dissolved upon heating in polar aprotic solvents containing LiCl as well as CCl3COOH, whereas polyimides were partially soluble in these solvents. No weight loss was observed up to 377–422°C in N2 and 355–397°C in air. The anaerobic char yields were 57–69% at 800°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 15–24, 1999 相似文献
7.
Yuhan Li Rizhe Jin Zhen Wang Zhiming Cui Wei Xing Lianxun Gao 《Journal of polymer science. Part A, Polymer chemistry》2007,45(2):222-231
A novel sulfonated diamine monomer, 2,2′‐bis(p‐aminophenoxy)‐1,1′‐binaphthyl‐6,6′‐disulfonic acid (BNDADS), was synthesized. A series of sulfonated polyimide copolymers containing 30–80 mol % BNDADS as a hydrophilic component were prepared. The copolymers showed excellent solubility and good film‐forming capability. Atomic force microscopy phase images clearly showed hydrophilic/hydrophobic microphase separation. The relationship between the proton conductivity and degree of sulfonation was examined. The sulfonated polyimide copolymer with 60 mol % BNDADS showed higher proton conductivity (0.0945–0.161 S/cm) at 20–80 °C in liquid water. The membranes exhibited methanol permeability from 9 × 10?8 to 5 × 10?7 cm2/s at 20 °C, which was much lower than that of Nafion (2 × 10?6cm2/s). The copolymers were thermally stable up to 300 °C. The sulfonated polyimide copolymers with 30–60 mol % BNDADS showed reasonable mechanical strength; for example, the maximum tensile strength at break of the sulfonated polyimide copolymer with 40 mol % BNDADS was 80.6 MPa under high moisture conditions. The optimum concentration of BNDADS was found to be 60 mol % from the viewpoint of proton conductivity, methanol permeability, and membrane stability. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 222–231, 2007 相似文献
8.
Tengjiao Hu Chengqing Wang Fuming Li Frank W. Harris Stephen Z. D. Cheng Chi Wu 《Journal of Polymer Science.Polymer Physics》2000,38(16):2077-2080
Eight 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride‐4,4′‐diamino‐3,3′‐dimethylbiphenyl (6FDA‐OTOL) fractions and seven 2,2′‐bis[4‐(3,4‐dicarboxyphenoxy) phenyl] propane dianhydride‐4,4′‐diamino‐3,3′‐dimethylbiphenyl (BISADA‐OTOL) fractions in cyclopentanone at 30 °C were characterized by a combination of viscometry and static and dynamic laser light scattering (LLS). In static LLS, the angular dependence of the absolute scattered intensity led to the weight‐average molar mass (Mw), the z‐average root mean square radius of gyration, and the second virial coefficient. In dynamic LLS, the Laplace inversion of each measured intensity–intensity time correlation function resulted in a corresponding translational diffusion coefficient distribution [G(D)]. The scalings of 〈D〉 (cm2/s) = 8.13 × 10−5 Mw−0.47 and [η] (dL/g) = 2.36 × 10−3 Mw0.54 for 6FDA‐OTOL and 〈D〉 (cm2/s) = 3.02 × 10−4 Mw−0.60 and [η] (dL/g) = 2.32 × 10−3 Mw0.53 for BISADA‐OTOL were established. With these scalings, we successfully converted each G(D) value into a corresponding molar mass distribution. At 30 °C, cyclopentanone is a good solvent for BISADA‐OTOL but a poor solvent for 6FDA‐OTOL; this can be attributed to an ether linkage in BISADA‐OTOL. Therefore, BISADA‐OTOL has a more extended chain conformation than 6FDA‐OTOL in cyclopentanone. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2077–2080, 2000 相似文献
9.
Yiwu Liu Yi Zhang Qi Lan Zexin Qin Siwei Liu Cunyuan Zhao Zhenguo Chi Jiarui Xu 《Journal of polymer science. Part A, Polymer chemistry》2013,51(6):1302-1314
A simple diamine (TetraPEDA) containing rigid nonplanar conjugated tetraphenylethylene (TetraPE) moieties was designed and synthesized through Wittig–Horner and Suzuki coupling reactions. Four kinds of high‐performance functional polyimides (PI) were thus prepared by the polymerization of TetraPEDA and four dianhydrides, respectively. Because of the introduction of the aromatic rigid nonplanar TetraPE structure, the PI exhibited special fluorescent characteristics, as the maximum fluorescence emission of the four PI was observed at 425–505 nm in NMP solution and at 470–491 nm in film state. Also these organo‐soluble PI showed outstanding properties, such as low dielectric constant (even without fluorinated substituent), light color, high glass transition temperatures (382–443 °C) and thermal stability in air (Td5% up to 565 °C), and excellent mechanical properties. The polymer memory devices with the configuration of indium tin oxide/PI/aluminum (ITO/PI/Al) exhibited distinct volatile memory characteristics of static random access memory, with an ON/OFF current ratio of 1 × 104 to 1 × 105. These functional PI showed attractive potential applications in the field of high performance flexible polymer photoconducting devices or fluorescent polymer memory devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
10.
Claudio A. Terraza Jin‐Gang Liu Yasuhiro Nakamura Yuji Shibasaki Shinji Ando Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2008,46(4):1510-1520
Highly refractive and transparent polyimides (PIs) based on fluorene‐bridged and sulfur‐containing monomers have been developed. An aromatic dianhydride, 4,4′‐[p‐thiobis(phenylenesulfanyl)]diphthalic anhydride (3SDEA), was polymerized with several fluorene‐containing diamines, including commercially available 9,9′‐bis(p‐aminophenyl)fluorene (APF), 9,9′‐bis[4‐(p‐aminophenoxy)phenyl]fluorene (OAPF), and newly synthesized 9,9′‐bis[4‐(p‐aminophenyl)sulfanylphenyl]fluorene (ASPF) to afford series A PIs. Meanwhile, series B PIs were obtained from a new dianhydride, 4,4′‐[(9H‐fluorene‐9‐ylidene)bis(p‐phenylsulfanyl)]diphthalic anhydride (FPSP) and two aromatic diamines, ASPF and 4,4′‐thiobis[(p‐phenylenesulfanyl)aniline] (3SDA) via a two‐step polycondensation procedure. The PIs exhibit good thermal stabilities, such as relatively high glass transition temperatures in the range of 220–270 °C and high initial thermal decomposition temperatures (T10%) exceeding 490 °C. The 9,9′‐disubstituted fluorene moieties endow the PI films with good optical transparency. The optical transmittances of the PI films at 450 nm are all higher than 80% for the thickness of about 10 μm. Furthermore, the highly aromatic fluorene moiety and flexible thioether linkages in the molecular chains of the PIs provide them with high refractive indices of 1.6951–1.7258 and small birefringence of 0.0056–0.0070. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1510–1520, 2008 相似文献
11.
Muhammed Aydin Tamer Uyar Mehmet Atilla Tasdelen Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2015,53(5):650-658
An 2‐ureido‐4[1H]pyrimidinone (UPy) motif with self‐association capability (through quadruple hydrogen bonds) was successfully anchored onto montmorillonite clay layers. Polymer/clay nanocomposites were prepared by specific hydrogen bonding interactions between surface functionalized silica nanoclays and UPy‐bonded supramolecular poly(ethylene glycol) or poly(?‐caprolactone). The mixed morphologies including intercalated layers with a non‐uniform separation and exfoliated single layers isolated from any stack were determined by combined X‐ray diffraction and transmission electron microscopic measurements. Thermal analyses showed that all nanocomposites had higher decomposition temperatures and thermal stabilities compared with neat polymer. The differential scanning calorimetric data implied that the crystallinity of polymers did not show essential changes upon introduction of organomodified UPy clays. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 650–658 相似文献
12.
Rahebeh Amiri Mina Haghdadi Ashkan Golshani Maryam Mohamadian Amiri Maryam Barikani 《中国化学会会志》2013,60(1):45-52
We have reported a simple and efficient reaction for the synthesis of some new functionalized azo structures which were prepared by electron deficient acetylenic compounds in the presence of triphenylphosphine. The characterization of the synthesized azo compounds has been determined by FTIR, UV‐Vis, 1H NMR, 13C NMR and Mass spectroscopic techniques. The influence of H‐bonding on the products has been shown by different experimental analysis. Also, the regioselectivity of the reaction, tautomerization equilibrium and the stability of products was investigated using DFT calculations at the B3LYP/6‐31G level of theory. 相似文献
13.
Sheng‐Huei Hsiao Yu‐Hui Chang 《Journal of polymer science. Part A, Polymer chemistry》2004,42(5):1255-1271
A new fluorinated diamine monomer, 2′,5′‐bis(4‐amino‐2‐trifluoromethylphenoxy)‐p‐terphenyl, was synthesized from the chloro‐displacement of 2‐chloro‐5‐nitrobenzotrifluoride with the potassium phenolate of 2,5‐diphenylhydroquinone, followed by hydrazine palladium‐catalyzed reduction. A series of trifluoromethyl‐substituted polyimides containing flexible ether linkages and laterally attached side rods were synthesized from the diamine with various aromatic dianhydrides via a conventional two‐step process. The inherent viscosities of the poly(amic acid) precursors were 0.84–1.26 dL/g. All the polyimides afforded flexible and tough films. The use of 4,4′‐oxydiphthalic anhydride and 2,2′‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride produced essentially colorless polyimide films. Most of the polyimides revealed an excellent solubility in many organic solvents. The glass‐transition temperatures of these polyimides were recorded between 254 and 299 °C by differential scanning calorimetry, and the softening temperatures of the polymer films stayed in the range of 253–300 °C according to thermomechanical analysis. The polyimides did not show significant decomposition before 500 °C in air or under nitrogen. These polyimides also showed low dielectric constants (2.83–3.34 at 1 MHz) and low moisture absorption (0.4–2.2%). For a comparative study, a series of analogous polyimides based on the nonfluorinated diamine 2′,5′‐bis(4‐aminophenoxy)‐p‐terphenyl were also prepared and characterized. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1255–1271, 2004 相似文献
14.
Synthesis and positive‐imaging photosensitivity of soluble polyimides having pendant carboxyl groups
Takafumi Fukushima Katsumoto Hosokawa Toshiyuki Oyama Takao Iijima Masao Tomoi Hiroshi Itatani 《Journal of polymer science. Part A, Polymer chemistry》2001,39(6):934-946
Polyimides having pendant carboxyl groups were prepared by a direct one‐pot polycondensation of 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) with 3,5‐diaminobenzoic acid (DABz) and bis[4‐(3‐aminophenoxy)phenyl]sulfone (m‐BAPS) in the presence of a γ‐valerolactone/pyridine catalyst system using N‐methyl‐2‐pyrrolidone (NMP)/toluene mixture as a solvent at 180 °C. The obtained polyimides were soluble in dipolar aprotic solvents such as dimethylformamide, dimethyl sulfoxide, and NMP as well as in tetrahydrofuran and aqueous basic solution. The solubility of the polyimides was dependent on the diamine composition. Photosensitve polyimide (PSPI) systems composed of the polyimides and diazonaphthoquinone compound as a photosensitive material gave positive‐tone behavior by UV irradiation, followed by development with aqueous tetramethylammonium hydroxide (TMAH) solution. The scanning electron microscopic photograph of the resulting image showed 10‐μm line/space resolution with about 15 μm of film thickness. The PSPIs baked at 350 °C for a short time had excellent thermal resistance comparable to the original polyimides. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 934–946, 2001 相似文献
15.
Ching Hsuan Lin Tung I. Wong Meng Wei Wang Hou Chien Chang Tzong Yuan Juang 《Journal of polymer science. Part A, Polymer chemistry》2015,53(4):513-520
A diallyl‐containing bisphenol, 1,1‐bis(3‐allyl‐4‐hydroxyphenyl)‐1‐(6‐oxido‐6H ‐dibenzo [c,e][1,2] oxaphosphorin‐6‐yl) ethane ( 1 ), was prepared by a two‐step procedure. Then, a diallyl‐containing diamine, 1,1‐bis(3‐allyl‐4‐(4‐aminophenoxy)‐phenyl)‐1‐(6‐oxido‐6H‐dibenzo [c,e][1,2] oxaphosphorin‐6‐yl)ethane ( 3 ), was prepared from the nucleophilic substitution of ( 1 ) with 4‐fluoronitrobenzene, followed by the reduction by Fe/HCl. A flexible polyimide ( 4 ) with curable diallyl linkages was prepared from the condensation of ( 3 ) and 4,4′‐oxydiphthalic anhydride in m‐cresol in the presence of isoquinoline. Curing polyimide ( 4 ) at 300 °C leads to thermosetting polyimide ( 5 ). We discussed the amounts of allyl group on Tg, coefficient of thermal expansion, and thermal stability of thermosetting polyimides, and found that thermal properties and dimensional stability of thermosetting polyimides increase with the amounts of cured allyl moieties. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 513–520 相似文献
16.
The intermolecular interactions in the dimers of m‐nisoldipine polymorphism were studied by B3LYP calculations and quantum theory of "atoms in molecules" (QTAIM) studies. Four geometries of dimers were obtained: dimer I (a‐dimer, O···H? N), dimer II (b‐dimer, O···H? N), dimer III (b‐dimer, π‐stacking‐c), and dimer IV (b‐dimer, π‐stacking‐p). The interaction energies of the four dimers are along the sequence of II>I>III>IV. The intermolecular distance of the interactions follows the order: I (O···H? N)II>III>IV, and the electrostatic character decreases along the sequence: I>II>III>IV. 相似文献
17.
Kenji Miyatake Naoki Asano Masahiro Watanabe 《Journal of polymer science. Part A, Polymer chemistry》2003,41(24):3901-3907
A series of novel sulfonated polyimides (equivalent weight per sulfonic acid = 310–744 g/equiv) containing 10–70 mol % 1,5‐naphthylene moieties were synthesized as potential electrolyte materials for high‐temperature polymer electrolyte fuel cells. The polycondensation of 1,4,5,8‐naphthalene tetracarboxylic dianhydride, 4,4′‐diamino‐2,2′‐biphenyldisulfonic acid, and 1,5‐diaminonaphthalene gave the title polymer electrolytes. The polyimide electrolytes were high‐molecular‐weight (number‐average molecular weight = 36.0–350.7 × 103 and weight‐average molecular weight = 70.4–598.5 × 103) and formed flexible and tough films. The thermal properties (decomposition temperature > 260 °C, no glass‐transition temperature), stability to oxidation, and water absorption were analyzed and compared with those of perfluorosulfonic acid polymers. The polyimide containing 20 mol % 1,5‐naphthylene moieties showed higher proton conductivity (0.3 S cm?1) at 120 °C and 100% relative humidity than perfluorosulfonic acid polymers. The temperature and humidity dependence of the proton conductivity was examined. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3901–3907, 2003 相似文献
18.
《Journal of polymer science. Part A, Polymer chemistry》2018,56(16):1844-1852
Reversible addition‐fragmentation chain transfer (RAFT) polymerization produced novel ABA triblock copolymers with associative urea sites within pendant groups in the external hard blocks. The ABA triblock copolymers served as models to study the influence of pendant hydrogen bonding on polymer physical properties and morphology. The triblock copolymers consisted of a soft central block of poly(di(ethylene glycol) methyl ether methacrylate) (polyDEGMEMA, 58 kg/mol) and hard copolymer external blocks of poly(2‐(3‐hexylureido)ethyl methacrylate‐co‐2‐(3‐phenylureido)ethyl methacrylate) (polyUrMA, 18‐116 kg/mol). Copolymerization of 2‐(3‐hexylureido)ethyl methacrylate (HUrMA) and 2‐(3‐phenylureido)ethyl methacrylate (PhUrMA) imparted tunable hard block Tg's from 69 to 134 °C. Tunable hard block Tg's afforded versatile thermomechanical properties for diverse applications. Dynamic mechanical analysis (DMA) of the triblock copolymers exhibited high modulus plateau regions (∼100 MPa) over a wide temperature range (−10 to 90 °C), which was indicative of microphase separation. Atomic force microscopy (AFM) confirmed surface microphase separation with various morphologies. Variable temperature FTIR (VT‐FTIR) revealed the presence of both monodentate and bidentate hydrogen bonding, and pendant hydrogen bonding remained as an ordered structure to higher than expected temperatures. This study presents a fundamental understanding of the influence of hydrogen bonding on polymer physical properties and reveals the response of pendant urea hydrogen bonding as a function of temperature as compared to main chain polyureas. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1844–1852 相似文献
19.
Eugene I. Mal'tsev Maria A. Brusentseva Dmitry A. Lypenko Vladimir I. Berendyaev Vladislav A. Kolesnikov Boris V. Kotov Anatoly V. Vannikov 《先进技术聚合物》2000,11(7):325-329
Optical and electroluminescent properties of a new soluble anthracene‐containing polyimide (ACPI) was studied. Solubility of ACPI in organic solvents allows direct spin casting of the polymer films exhibiting intense photo‐ and electroluminescence (EL) in the visible range. This non‐conjugated polymer was used as emitting and electron‐hole transporting layers in polymer light‐emitting devices (LEDs). EL properties of the uni‐ and bilayer LEDs are discussed in terms of the band structure, bipolar transport and electron donor‐acceptor interactions. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
20.
The hollow composite spheres with a raspberry‐like structure were prepared by a self‐assemble heterocoagulation based on the inter‐particle hydrogen‐bonding interaction between the amide groups of hollow poly (N,N′‐methylenebisacrylamide‐co‐N‐isopropyl acrylamide) (P(MBA‐co‐NIPAAm)) microspheres and the carboxylic acid groups of poly(ethyleneglycol dimethacrylate‐co‐methacrylic acid) (P(EGDMA‐co‐MAA)) nanoparticles, in which P(EGDMA‐co‐MAA) nanoparticle acted as the corona and the hollow P(MBA‐co‐NIPAAm) microsphere behaved as the core. The control coverage of the corona particles on the surface of hollow core microspheres of P(MBA‐co‐NIPAAm)/P(EGDMA‐co‐MAA) hollow composite sphere was studied in detail through adjustment of the mass ratio between the core and corona particles. The effect of the pH on the stability of the raspberry‐like hollow spheres was investigated. The polymer particles and the resultant heterocoagulated raspberry‐like hollow spheres were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献