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1.
A novel type of crosslinkable waterborne polyurethane ionomer was prepared by the acetone process. Two new types of sulfonated diols compatible with this process were synthesized from dimethyl 5‐sodium sulfo isophthalate using a one‐ or two‐stage method. Isocyanate‐terminated polyurethane oligomers were prepared from the sulfonated diols with various combinations of diols and diisocyanates and subsequently reacted with amino silane derivatives. Stable, low‐volatile organic chemical, waterborne dispersions of the sulfo‐urethane silanol polymers spontaneously crosslink upon drying without extra additives or processing steps. Despite the lack of organic coalescing solvents, the dispersions have minimum film‐forming temperatures below 10 °C, regardless of glass‐transition temperature. Tensile strengths up to 6000 psi with elongations between 300 and 600% were obtained for the crosslinked films. The hard‐segment content of the films can be controlled to produce films with a Sward–Rocker hardness value up to 42. Through silane end‐group modification, the crosslinking density of the films can also be modified to produce polyurethanes with a wide range of physical properties. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3037–3045, 2002  相似文献   

2.
A novel long chain linear unsaturated terminal diisocyanate, 1,16‐diisocyanatohexadec‐8‐ene (HDEDI) was synthesized from oleic acid via Curtius rearrangement. Its chemical structure was identified by FTIR, 1H NMR, 13C NMR, and HRMS. This diisocyanate was used as a starting material for the preparation of entirely bio‐based polyurethanes (PUs) by reacting it with canola diol and canola polyol, respectively. The physical properties and crystalline structure of the PUs prepared from this diisocyanate were compared to their counterparts prepared from similar fatty acid‐derived diisocyanate, 1,7‐heptamethylene diisocyanate (HPMDI). The HDEDI based PUs demonstrated various different properties compared to those of HPMDI based PUs. For example, HDEDI based PUs exhibited a triclinic crystal form; whereas HPMDI based PUs exhibited a hexagonal crystal lattice. In addition, canola polyol‐HDEDI PU demonstrated a higher tensile strength at break than that of canola polyol‐HPMDI, attributed to the higher degree of hydrogen bonding associated with the former sample. Nevertheless, lower Young's modulus and higher elongation in canola polyol‐HDEDI PU were obtained because of the flexibility of the long chain introduced by the HDEDI diisocyanate. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3302–3310, 2010  相似文献   

3.
l ‐Lactide (l ‐LA) was polymerized in the presence of N‐methyldiethanolamine as an initiator and Sn(Oct)2 as a catalyst to give hydroxy‐telechelic poly(l ‐lactide) (PLLA‐diol) bearing a tertiary amine group at the center of the polymer chain. Successive chain extension of the PLLA‐diol with hexamethylene diisocyanate afforded PLLA‐based poly(ester‐urethane)s (PEU) with equally spaced tertiary amine groups. Treatment of the PEU with iodomethane converted tertiary amine groups to quaternary ammonium groups to give cationic ionomers (PEU‐MeI). The thermal, mechanical, hydrophilic, and biodegradation properties of the obtained polymers were investigated. The thermal properties of the PEUs and the PEU‐MeIs were similar each other. The PEU‐MeIs exhibited higher tensile modulus than those of the starting PEUs. The contact angles of water on the PEU‐MeIs were lower than those of the PEUs with similar NMDA content indicating their higher hydrophilicity. In compost degradation tests, the PEU‐MeIs showed slower degradation than those of the PEUs. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4423–4428  相似文献   

4.
Poly(styrene-co-diethyl vinylphosphonate) copolymers were synthesized by free radical copolymerization. The ester groups of the copolymers were hydrolyzed to phosphonic acid groups, and the sodium and zinc salts ionomers were obtained by neutralization. The structure and the thermal and viscoelastic properties of the copolymers and ionomers were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and small-angle X-ray scattering. The phosphonate ester lowered the glass transition temperature (Tg) of polystyrene. The free acid derivatives and metal phosphonates increased Tg and produced a rubbery plateau region in the viscoelastic properties due to the formation of a physical network. The acid and salt ionomers exhibited microphase-separated morphologies and were thermorheologically complex. The phosphonic acid derivatives absorbed relatively little water, even for materials with ion-exchange capacities greater than 1.0 mEq/g, and were not conductive, which made them unsuitable for application as proton exchange membranes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3628–3641, 2004  相似文献   

5.
Supramolecular polyurethane ureas are expected to have superior mechanical properties primarily due to the reversible, noncovalent interactions such as hydrogen bonding interactions. We synthesized polyurethane prepolymers from small molecular weight of poly(tetramethylene ether)glycol and isophorone diisocyanates, which were end capped with propylamine to synthesize polyurethane ureas with high contents of urea and urethane groups for hydrogen‐bonding formations to facilitate self‐healing. The effects of polyurethane urea molecular weight (3000 ≤ Mn ≤ 9000), crosslinking, and cutting direction were studied in terms of thermal, mechanical, and morphological properties with an emphasis on the self‐healing efficiency. It was found that the thermal self‐healability was more pronounced as the molecular weight of polyurethane urea decreased, showing a maximum of more than 96% with 3000 Mn when the sample was cut along the stretch direction. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 468–474  相似文献   

6.
A series of positively charged imidazolium‐functionalized ionic polyurethanes (IPUs) were prepared in one‐step polymerization process by polymerization of presynthesized short‐chain imidazolium‐based ionic diol, polyethylene glycols with different molecular weights as long‐chain diols, and toluylene‐2,4‐diisocyanate. The structures of IPUs are confirmed by 1H NMR analysis, and the thermogravimetric analysis measurement indicates that the IPUs have high degradation temperature. Fluorescent nanocrystal–polymer composites CdTe–IPU can be prepared conveniently, by the electrostatic interaction between positively charged IPUs and the negatively charged aqueous CdTe quantum dots (QDs). UV–vis absorption and photoluminescence spectra indicate the photochemical stability and strong fluorescent emission of CdTe–IPU composites. The quantum yields (QYs) of the composites are high and basically restore the QYs of the pure QDs. In addition, the transmission electron microscopy photographs show that the QDs in composites are uniform (about 3 nm in diameter) and monodisperse. The obtained nanocomposites are powder or elastomers with good film building. The casted CdTe–IPU films are transparent under visible light, and the colors of the composites and their films are vivid under a UV lamp. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

7.
As a viable alternative to the petrochemical polyols in polyurethanes (PUs), a new soybean oil‐based polyol (PSBO) with high functionality of hydroxyl groups and built‐in (preformed) urethane bonds was introduced. At first, a facile and improved method was developed for the transformation of epoxidized soybean oil (ESBO) to carbonated soybean oil (CSBO). Then ring‐opening reaction of carbonated oil with ethanolamine (ETA) led to the polyol. After characterization by conventional spectroscopic and analytical methods, PSBO was used for the formulation of novel one‐pack PU electroinsulating wire enamels. Tunable mechanical, thermal, and electrical properties for the final PUs were achieved by replacing 10 wt% of PSBO with poly(propylene glycol) (PPG) at different number average molecular weights of 725, 1000, 2000, 4000. Investigation of the results showed that these soy‐based PUs offer excellent thermal and electrical insulating properties. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

8.
A type of bi‐triethoxysilane endcapped polyurethane/urea (SPU) with well‐defined structure was synthesized through the reaction of polyethylene glycol (PEG), 2, 4‐toluene diisocyanate (TDI) and bis‐[trimethoxysiylpropyl]amine (DB‐520). The structure of the resultant product was confirmed by Fourier transform infrared (FT‐IR) and Nuclear magnetic resonance (1HNMR). Different SPU nanoparticles were obtained with the assistance of hydrogen ion, and their morphologies were characterized by combination of transmission microscopy (TEM) and FT‐IR. The results showed that with increasing the concentration of hydrogen ions, the ratio of condensation accordingly increased, accompanying with the nanoparticle's morphology change from sphere to rod. Furthermore, the dispersion mechanism of SPU chains in protonic solution and the arrangement of molecular chains in hybrid particles were proposed. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

9.
A series of polyurethane (PU) microspheres, based on 4,4′‐diphenylmethane diisocyanate and 1,4‐butanediol or a mixture of 1,4‐butanediol and polyether glycol (M = 1400) were synthesized by a one‐step method. The obtained PU microspheres were characterized by infrared spectroscopy, polarizing optical microscopy and dynamic thermogravimetry. Morphology studies of PU microspheres revealed that the material consists of spherical particles with relatively narrow particle size distribution in the range 1–100 µm and preferably between 10 to 50 µm; the obtained polymers were thermally stable up to 533–573 K. Maltogenase from Bacillus stearothermophilus was immobilized onto PU microspheres, synthesized using different ratios of components. High yield (about 100%) and efficiency (over 100%) of immobilization were obtained. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

10.
A multiblock fluorinated polyurethane was synthesized using tetraphenylethane‐based polyurethane as macroiniferter to free‐radically polymerize 1H,1H,3H‐trihydro perfluoro‐2,4‐dimethylpentyl methacrylate (FDPMA). Simultaneous self‐assembly occurred in FDPMA polymerization process and various nanostructures, like multicore particles, formed depending on FDPMA concentration. Fluorophobic effect and the cooperation of the fluorinated blocks with polyurethane blocks are demonstrated to be the main contribution. That soluble FDPMA in DMF becomes insoluble after polymerization triggers the self‐assembly process and leads to the nanostructure formation, and the polyurethane blocks that are soluble in DMF and immiscible with the fluorinated blocks stabilize the discrete nanostructures. Further, the nanostructures in solutions can evolve into various morphologies, such as disk and fiber, when dried to solid state. All these results not only reveal the feasibility and robustness of the multiblock copolymer on the modulation of self‐assembly structure but also represent a facile and efficient approach for novel nanostructure construction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013  相似文献   

11.
To obtain controllable and biocompatible drug carriers, a series of amphiphilic biodegradable multiblock polyurethanes end‐capped by phosphorylcholine were designed and synthesized using L ‐lysine ethyl ester diisocyanate (LDI), poly(lactic acid)‐poly(ethylene glycol)‐poly(lactic acid) (PLA‐PEG‐PLA), 1,4‐butanediol (BDO), and 4‐hydroxy butyl phosphorylcholine (BPC) was used as end‐capper to improve their biocompatibility and provide them with tailored micellization characteristics. The resulting polyurethanes were fully characterized with proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FT‐IR), gel permeation chromatograph (GPC), and differential scanning calorimetry (DSC). More importantly, these phosphorylcholine‐capped polyurethanes can self assemble into micelles that are smaller than 100 nm in diameter. Their particle sizes, size distributions, and zeta potentials can also be tailored by varying the phosphorylcholine content. The incorporation of phosphorylcholine into these polyurethanes has significantly affected their degree of microphase separation, bulk and micelle degradation rates. This work provides a new and facile approach to prepare amphiphilic block copolymer micelles with controllable performances, which could be useful for drug delivery and bioimaging applications. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

12.
Biodegradable polyurethane elastomers with the potential for applications in medical implants were synthesized from the reaction of epoxy‐terminated polyurethane prepolymers (EUPs) with 1,6‐hexamethylenediamine as a curing agent. EUPs were themselves prepared from the reaction of glycidol and isocyanate‐terminated polyurethanes made from different molecular weights of poly(ε‐caprolactone) (CAPA) and 1,6‐hexamethylene diisocyanate. All materials were characterized by spectroscopic methods. The curing conditions were optimized by gel content measurements. The curing kinetic and kinetic parameters were determined from differential scanning calorimetry measurements. The effects of changing the crosslink density and crystallinity of elastomers via the alteration of the CAPA polyol molecular weight on the physical, mechanical, and degradation properties of the final elastomeric polymers were examined fully. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2985‐2996, 2005  相似文献   

13.
We prepared N‐methyl‐substituted polyurethanes with different substitution degrees from sodium hydride, methyl p‐toluene sulfonate, and polyether–polyurethane containing poly(oxytetramethylene) glycol, 4,4′‐diphenylmethane diisocyanate, and 1,4‐butanediol. The chemical structures were characterized with Fourier transform infrared and 1H NMR. To investigate the effects of the N‐substitution degree on the morphology, thermal stability, and mechanical properties, we used differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. As the substitution degree increased, the new free (1708 cm?1) and bonded (1650 cm?1) carbonyl peaks increased. There was no bonded carbonyl peak in fully substituted polyurethane because the urethane groups had no hydrogen. At a small substitution degree, we observed a slight increase in the glass‐transition temperature and decrease in the endotherms of soft‐segment and hard‐segment domains due to the decrease in the hard‐segment domain and the increase in the urethane groups in the soft‐segment domain. The hard‐segment domain decreased and then disappeared as the N‐methyl substitution degree increased. These changes in the morphology resulted (1) in decreased modulus and tensile strength for the films because of the decrease in physical crosslinking points and (2) improved thermal stability as the substitution degree increased. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4077–4083, 2002  相似文献   

14.
This study describes the fabrication and characterization of castor oil‐based waterborne polyurethane/polyaniline (COWPU/PAni) conducting polymer blend films. The COWPU synthesized from isophorone diisocyanate was reacted with castor oil to form prepolymers, which were chain extended by reacting it with N‐methyldiethanolamine. Quaternization and self‐emulsification including deionized water followed in COWPU dispersions. Also, COWPU/PAni hybrid dispersions were synthesized with 2, 4, and 6 wt% of PAni–dodecyl benzene sulfonic acid to make different conductive composites. The outcome of COWPU/PAni was characterized by Fourier transform infrared spectrometer, differential scanning calorimeter, thermogravimetric analysis, dynamic mechanical and thermal analyzer, and scanning electron microscopy analysis. According to Fourier transform infrared spectrometer analysis, hydrogen bonding appears between –NH of PAni and C?O of COWPU. Meanwhile, incorporating PAni can improve the thermal stability of COWPU. The resulting COWPU/PAni conducting blend films can be used as antistatic and anticorrosive coating materials. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

15.
Various novel block cationomers consisting of polyisobutylene (PIB) and poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) segments were synthesized and characterized. The specific targets were various molecular weight diblocks (PIB‐b‐PDMAEMA+) and triblocks (PDMAEMA+b‐PIB‐b‐PDMAEMA+), with the PIB blocks in the DPn = 50–200 range (number‐average molecular weight = 3,000–9000 g/mol) connected to blocks of PDMAEMA+ cations in the DPn = 5–20 range (where DP is the number‐average degree of polymerization). The overall synthetic strategy for the preparation of these block cationomers had four steps: (1) synthesis by living cationic polymerization of mono‐ and diallyltelechelic polyisobutylenes, (2) end‐group transformation to obtain PIBs fitted with termini capable of mediating the atom transfer radical polymerization (ATRP) of DMAEMA, (3) ATRP of DMAEMA, and (4) quaternization of PDMAEMA to PDMAEMA +I? by CH3I. Scheme 1 shows the microarchitecture and outlines the synthesis route. Kinetic and model experiments provided guidance for developing convenient synthesis methods. The microarchitecture of PIB–PDMAEMA di‐ and triblocks and the corresponding block cationomers were confirmed by 1H NMR and FTIR spectroscopy and solubility studies. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3679–3691, 2002  相似文献   

16.
A series of novel block anionomers consisting of polyisobutylene (PIB) and poly(methacrylic acid) (PMAA) segments were prepared and characterized. The specific targets were various molecular weight diblocks (PIB‐b‐PMAA?), triblocks (PMAA?b‐PIB‐b‐PMAA?), and three‐arm star blocks [Φ(PIB‐b‐PMAA?)3] consisting of rubbery PIB blocks with a number‐average degree of polymerization of 50–1000 (number‐average molecular weight = 3000–54,000 g/mol) connected to blocks of PMAA? anions with a number‐average degree of polymerization of 5–20. The overall strategy for the synthesis of these constructs consisted of four steps: (1) synthesis by living cationic polymerization of t‐chloro‐monotelechelic, t‐chloro‐ditelechelic, and t‐chloro‐tritelechelic PIBs; (2) site transformation to obtain PIBs fitted with termini capable of mediating the atom transfer radical polymerization (ATRP) of tert‐butyl methacrylate (tBMA); (3) ATRP of tBMA, and (4) hydrolysis of poly(tert‐butyl methacrylate) to PMAA?. The architectures created and the synthesis steps employed are summarized. Kinetic and model experiments greatly assisted in the development of convenient synthesis methods. The microarchitectures of the various block anionomers were confirmed by spectroscopy and other techniques. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3662–3678, 2002  相似文献   

17.
Novel microcapsules (MCs) with organic/inorganic hybrid shell were successfully fabricated using epoxy resin as core material and nano boron nitride (BN) and mesoporous silica (SBA‐15) as inorganic shell materials in aqueous solution containing a water‐compatible epoxy resin curing agent. The morphologies, thermal properties and Young's moduli of MCs were investigated. The results indicated that epoxy resins were encapsulated by BN/SBA‐15/epoxy polymer hybrid layer, the resulting MCs were spherical in shape and the introduction of inorganic particles made MCs had rough surface morphology. The mean modulus value of MCs was from 2.8 to 3.1 GPa. The initial decomposition temperature (Tdi) of MCs at 5 wt% weight loss was from 309 to 312°C. MCs showed excellent thermal stability below 260°C. The structures and properties of MCs could be tailored by controlling the weight ratio of inorganic particle. When the weight ratio of BN to SBA‐15 was 0.15:0.10, MCs had the highest Tdi and modulus. The resulting MCs were applied to high performance 4,4′‐bismaleimidodiphenylmethane/O,O′‐diallylbisphenol A (BMI/DBA) system to design high performance BMI/DBA/MC systems. Appropriate content of MCs could improve the fracture toughness and maintain the glass transition temperature (Tg) of BMI/DBA system. The core materials released from fractured MCs could bond the fracture surfaces of the BMI/DBA matrix through the polymerization of epoxy resins. When the healing temperature schedule of 100°C/2h+150°C/1h was applied, 15 wt% MCs recovered 98% of the virgin fracture toughness of BMI/DBA. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

18.
A series of sulfonated homo‐ and random co‐polyimides (co‐SPI) based on 2,4‐diaminobenzenesulfonic acid (2,4‐DABS) and 2,5‐diaminobenzenesulfonic acid (2,5‐DABS) has been synthesized via conventional two‐step polyimidization method. 2,4‐DABS and 2,5‐DABS were used as sulfonated diamine compounds, 4,4′‐oxydianiline (ODA) and 4,4′‐diaminodiphenyl sulfone (DDS) were used as non‐sulfonated diamine compounds. Mixtures of sulfonated and non‐sulfonated diamine compounds were reacted with benzophenonetetracarboxylic dianhydride (BTDA) to obtain co‐SPI membranes. Molar ratios of sulfonated to non‐sulfonated diamine were systematically varied to produce copolymers of controlled compositions. The co‐SPIs were evaluated for thermal oxidative stability, ion exchange capacity (IEC), water uptake, proton conductivity, solubility, and hydrolytic stability. Proton conductivity and hydrolytic stability of the co‐SPIs were compared with the fully aromatic polyimide, homo‐SPIs (BTDA/2,4‐DABS and BTDA/2,5‐DABS). Regarding thermogravimetric analysis (TGA) analysis, it is concluded that desulfonation temperature in the range of 200–350°C suggests high stability of sulfonic acid groups. co‐SPIs with 40 mol% of 2,4‐DABS showed similar or higher proton conductivity than Nafion® 117 in water. Proton conductivity values of the co‐SPIs were mainly a function of IEC and water uptake. Consequently, the optimum concentration of 2,4‐DABS was found to be in the range of 30–40 mol% from the viewpoint of proton conductivity, IEC, and hydrolytic stability. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

19.
Sulfonated polyimides exhibit high strength, good film‐forming ability, chemical resistance, and, in their hydrated state, relatively high proton conductivity. Here we report the one‐pot synthesis of sulfonated polyimide‐polysiloxane segmented copolymers through the reaction of a dianhydride with a mixture of three diamines: a nonionic aromatic diamine (4,4′‐oxydianiline), a sulfonated diamine (4,4′‐diamino‐2,2′‐biphenyldisulfonic acid), and a telechelic diamino polysiloxane. Copolymer compositions were evaluated using 1H NMR and size‐exclusion chromatography. The presence of ion‐containing diamines in the reaction mixture inhibited stoichiometric incorporation of hydrophobic siloxane segments. Siloxane segments were found to lower the thermal stability of the polyimide host. Copolymers with and without siloxane segments were cast into free‐standing films. Equilibrium water sorption studies of cast films show that, for the compositions studied here, the presence of siloxane segments does not interfere with water swelling, suggesting that a microphase‐segregated morphology may exist. TEM and SAXS analyses show evidence of phase‐segregation in sulfonated polyimides and reveal that siloxane segments strongly affect ionic clustering. However, proton conductivity only changes slightly when polysiloxane segments are incorporated. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3747–3758, 2007  相似文献   

20.
A series of parent poly(aryl ether ketone)s bearing different content of unsaturated pendant propenyl groups were synthesized via nucleophilic substitution polymerization from 3,3′-diallyl-4,4′-dihydroxybiphenyl, 9,9′-bis(4-hydroxyphenyl) fluorene and 4,4′-difluorobenzophenone. The polymers with pendant aliphatic sulfonic acid groups were further synthesized by free radical thiol-ene coupling reactions between 3-mercapto-1-propanesulfonic sodium and the parent propenyl functional copolymers. The resulting sulfonated polymers with high inherent viscosity (1.83-4.69 dL/g) were soluble in polar organic solvents and can form flexible and transparent membranes by casting from their solutions. The copolymers with different ion exchange capacity could be conveniently synthesized by varying the monomers ratios. Transmission electron microscopy (TEM) was used to examine the microstructures of the membrane and the results revealed that significant hydrophilic/hydrophobic microphase separation with spherical, uniform-sized (5-10 nm) and well-dispersed hydrophilic domains was afforded. The proton conductivities of the as-prepared membranes and the state-of-the-art Nafion 117 membrane in fully hydrated state were investigated. The results revealed that the proton conductivity of the synthesized membranes increased more remarkably than that of Nafion 117 membrane with increasing temperature. The membrane with 1.69 mequiv/g of IEC had a conductivity of 2.5 × 10−2 Scm−1 at 100 °C. The membranes also possessed excellent mechanical properties, good thermal, oxidative, hydrolytic and dimensional stabilities.  相似文献   

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