Soluble Poly Research Articles

A synthetic approach for water soluble hyperbranched poly(N,N-ethylidenebis(N-2-chloroacetyl acrylamide)) with high degree of branching via atom transfer radical polymerization/self-condensing vinyl polymerization

A novel acrylamide A2B2* (A = alkene, B* = alkyl chlorine) type inimer was obtained from commercially available 1,2-ethylenediamine, chloroacetyl chloride and acryloyl chloride. The as-prepared monomer can form water-soluble hyperbranched poly(N,N-ethylidene bis(N-2-chloroacetyl acrylamide))s (HPECA) through atom transfer radical polymerization/self-condensing vinyl polymerization method in the presence alkyl chlorine/CuCl/2,2-bipyridine activation system which can effectively suppress the gelation formation. 1H-NMR spectra and dual detector size exclusion chromatography proved the hyperbranched structure indisputably, and the degree of branching was determined by the detailed analyses of 1H-NMR spectra. The trend of the degree of branching was in consistent with the result of Mark-Houwink exponent a. The experiment results suggested that the conversion was 67%, Mw = 13.2 × 104, Mark-Houwink a = 0.282 and the degree of branching = 64% when the reaction temperature was 120 °C, reaction time = 168 h and N,Nethylidene bis(N-2-chloroacetyl acrylamide):Cu(I) = 50:0.62.

Aspects of determining the molecular weight of cyclodextrin polymers and oligomers by static light scattering

Methodic issues affecting the use of static light scattering to determine the average molecular weight of cyclodextrin poly- and oligomers are discussed. The critical features which enable accurate measurement such as aggregation behavior and segment–segment interaction are elucidated. Static light scattering data supported with globule size and aggregate state analysis (as determined by dynamic light scattering) allowed the aggregate-free state of the samples to be justified and the ideal globular conformation of the macromolecules to be corroborated. These molecular characteristics were demonstrated for uncharged, charged and fluorescent randomly crosslinked water soluble cyclodextrin poly- and oligomers.

Synthesis and Characterization of Poly(azomethine ester)s with a Pendent Dimethoxy Benzylidene Group

Recently, soluble poly(azomethine ester)s with good thermal stability and liquid crystalline properties are much sought after in opto-electronic field. One such attempt was to synthesize poly(azomethine ester)s with a pendent group. In this study, the newly synthesized diacid monomer benzalaniline 3’-4’dimethoxy terepthalic acid was condensed with two diol monomers to get the polymers with pendent benzylidene group. The diacid monomer was characterized by UV, IR, NMR and CHNS analysis. The polymers were characterized by IR, TGA, and for liquid crystalline property. Polymer-I showed the highest thermal stability upto 335°C. Polymer-II exhibited liquid crystalline nature along with good solubility and thermal stability.

Electrochemical analysis of a PPV derivative thin film doped with ß-ketoimine calix[4]arene in the dark and under illumination for the detection of Hg2+ ions

Conducting polymer can be used as the polymer matrix of the ion sensitive membrane (containing electroactive sites), which would exhibit intrinsic mixed ionic and electronic conductivity. In this work, a soluble poly(p-phenylene vinylene) derivative (MEH-PPV) has been used as the electroconducting polymer to immobilize the ß-ketoimine calix[4]arene derivative. Indium-thin oxide (ITO) electrode coated with the thin films of MEH-PPV and composite MEH-PPV/ß-ketoimine Cal[4] are designed for the determination of trace amounts of Hg2+ ions. Surface morphology properties were examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The presented results show that the incorporation of calixarene derivative into MEH-PPV polymer improved the surface smoothness. Contact angle measurements were used to study hydrophobicity and surface energy properties of thin films. We observed that the best adhesion on the ITO surface is for the MEH-PPV/ß-ketoimine Cal[4] surface due to the presence of (OH) groups coming from the molecules of derivative calix[4]arene. Thin films were characterized by electrochemical impedance spectroscopy (EIS) in the dark and under illumination. The impedance behavior of the modified electrodes is modeled by an equivalent electrical circuit using the Z-View software. From the impedance plots, the bulk resistance and ionic conductivity of the membranes is an important factor determining the ability of ions to pass across the membrane. Marked differences in the ionic conductivity are observed as a function of the light excitation. The charge transfer processes at the electrode/electrolyte interface was carefully examined in the dark and under illumination. Optical excitation of both membranes revealed that the sensing activity of the MEH-PPV/ß-ketoimine Cal[4] modified electrode can improve the measuring sensitivity of Hg2+ ions compared to the MEH-PPV modified electrode.

Flexible, optically transparent, high refractive, and thermally stable polyimide–TiO2 hybrids for anti-reflection coating

In this study, flexible and transparent polyimide–nanocrystalline-titania hybrid optical films with a high titania content (up to 50 wt%) and thickness (15 μm) were prepared from new soluble poly(o-hydroxy-imide)s and fabricated for a three-layer antireflection coating. The hydroxyl groups on the backbone of the polyimides could provide a reaction site for organic–inorganic bonding and resulted in homogeneous hybrid solutions by controlling the mole ratio of titanium butoxide/hydroxyl groups. The well-dispersed nanocrystalline-titania was demonstrated by XRD and TEM measurements. The flexible hybrid films with good surface planarity, thermal dimensional stability, tunable refractive index (1.63–1.80 at 633 nm), and high optical transparency were successfully obtained and further utilized to prepare a three-layer anti-reflection coating, indicating its potential optical applications.

Hollow structured SrMoO4:Yb3+, Ln3+ (Ln = Tm, Ho, Tm/Ho) microspheres: tunable up-conversion emissions and application as drug carriers.

In this study, a facile and mild one-pot approach was employed to prepare hollow-structured SrMoO4 spheres using soluble sodium poly(4-styrenesulfonate) (PSS) as a soft template. It is found that the as-prepared product exhibits hollow spherical morphology, good dispersity, and narrow size distribution. The formation mechanism has also been proposed. Tunable multicolor and bright white up-conversion (UC) emissions were successfully realized by precisely adjusting the doping sensitizer (Yb3+) and activator (Tm3+, Ho3+, and Tm3+/Ho3+) concentration in the host matrix. MTT assay shows the good biocompatibility of SrMoO4:Yb3+/Tm3+ hollow spheres, which were used as an anti-cancer drug carrier to evaluate the loading and controlled release behavior by selecting doxorubicin hydrochloride (DOX) as a model drug. Drug release tests reveal a sustained drug release behavior and especially the UC emission intensities of the drug loaded system increase with the released amount of DOX, indicating that the extent of drug release can be monitored or tracked by the change in emission intensity. Moreover, the in vitro cytotoxic effect against SKOV3 ovarian cancer cells of the DOX-loaded carrier was investigated and the endocytosis process of drug-loaded microspheres was studied using confocal laser scanning microscopy (CLSM) and flow cytometry. Considering the good biocompatibility, high drug loading amount and obvious sustained drug release properties, the hollow microspheres are highly promising in biological areas.

Conjugated polymers consisting of quinacridone and quinoxaline as donor materials for organic photovoltaics: orientation and charge transfer properties of polymers formed by phenyl structures with a quinoxaline derivative

In this study, a highly soluble poly[quinacridone-alt-quinoxaline] series (PQCQx, PQCTQx, PQCTPz) was synthesized through the Suzuki coupling reaction by introducing planar quinacridone and highly soluble quinoxaline. The polymers were soluble in general organic solvents, and the Mn was 15.6–85.0 kg mol−1. The optical band gap energy was 1.82–1.97 eV, which was similar to the band gap of a benzothiadiazole derivative. The HOMO and LUMO levels of the polymers were −5.32 to −5.46 eV and −3.40 to 3.50 eV, respectively. According to XRD measurements, the PQCQx and PQCTPz showed the formation of an ordered lamellar structure and conventional edge-on π-stacking, while the PQCTQx showed face-on formation relative to the substrate. This study also evaluated the OPV characteristics by fabricating a bulk-heterojunction-type polymer solar cell. For the device structure of ITO/PEDOT:PSS/active layer (PQCTQx:PC71BM = 1 : 2 with DIO)/PFN/Al, the values of open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF) and power conversion efficiency (PCE) were 0.85 V, 7.6 mA cm−2, 54.9%, and 3.6%, respectively.

Hydrophobically Modified Poly(Allylamine) Hydrogels Containing Internal Quaternary Ammonium Groups as Cholesterol Lowering Agents: Synthesis, Characterization, and Biological Studies

Syntheses and physico-chemical characterization of a series of amphiphilic cationic hydrogels bearing pendant quaternary ammonium groups based on poly(allylamine) backbone are reported. These amphiphilic hydrogels were prepared by crosslinking soluble poly(allylamine) with epichlorohydrin followed by alkylation of the resulting gel with different functional alkyl chlorides bearing quaternary ammonium groups. Equilibrium swelling characteristics of these amphiphilic hydrogels were determined under a variety of solvent conditions. The roles of different parameters such as degree of crosslinking, degree of alkylation, and nature of alkylating agents on the swelling properties of these hydrogels were investigated. As part of a continuing structure-activity relationship study for the discovery of systemically non-absorbed cholesterol lowering agents, these amphiphilic hydrogels were also evaluated for their bile acid sequestration properties. Preliminary in vivo studies suggest these cationic hydrogels are potent bile acid sequestrants.

A new route to functional polymers: atom-economical synthesis of poly(pyrazolylnaphthalene)s by rhodium-catalyzed oxidative polycoupling of phenylpyrazole and internal diynes

A new route for atom-economical synthesis of functional polymers was developed. Oxidative polycoupling of 3,5-dimethyl-1-phenylpyrazole with 4,4′-(α,ω-alkylenedioxy) bis(diphenylacetylene)s and 1,2-diphenyl-1,2-bis[4-(phenylethynyl)phenyl]ethene, respectively, were catalyzed by [Cp*RhCl2]2, 1,2,3,4-tetraphenylcyclopenta-1,3-diene and copper(II) acetate in dimethylformamide under stoichiometric imbalance conditions, affording soluble poly(pyrazolylnaphthalene)s in satisfactory yields (isolation yield up to 82%) with high molecular weights (Mw up to 35 700). All the polymers were thermally stable, losing little of their weight at high temperatures of 323–422 °C. They possessed good film-forming property and their thin solid films showed high refractive indices (RI = 1.747 − 1.593) in a wide wavelength region of 400–1000 nm. The polymer carrying tetraphenylethene units displayed a phenomenon of aggregation-induced emission and showed enhanced light emission in the aggregated state. The emission of its nanoaggregates could be quenched efficiently by picric acid in both solution and solid states, suggesting that it is a promising sensitive chemosensor for detecting explosives for real-world applications.

Near Infrared Absorbing Soluble Poly(cyclopenta[2,1-b:3,4-b′]dithiophen-4-one)vinylene Polymers Exhibiting High Hole and Electron Mobilities in Ambient Air

We report the synthesis of two novel cyclopenta[2,1-b:3,4-b′]dithiophen-4-one monomers containing solubilizing alkyl groups in the peripheral 3,5 positions. Polymerization with (E)-1,2-bis(tributylstannyl)-ethylene under Stille coupling conditions afforded the first reported examples of soluble poly(cyclopentadithiophen-4-one)vinylenes. The resulting polymers absorb in the near-infrared, with a maximum thin film absorbance around 815 nm and have optical band gaps of 1.25 eV. The polymers exhibit promising ambipolar field effect transistor performance, with average saturated mobilities of 0.5 cm2 V–1 s–1 for holes and 0.12 cm2 V–1 s–1 for electrons. The ambipolar transistors operate in both the hole and electron transport regimes in ambient air. Prolonged exposure to ambient atmosphere leads to a gradual loss of the electron transport behavior, with little change observed in the p-type mobility.

Formation of extended ionomeric network by bulk polymerization of l,d-lactide with layered-double-hydroxide

We report the formation of an ionomeric network in a poly(l,d-lactide) hybrid nanocomposite, (PLDLA-HYB) during in-situ melt polymerization of l,d-lactide in the presence of magnesium/aluminum layered-double-hydroxide (LDH) without added catalyst.The effect of LDH mass loading and reaction time on molecular mass and yield of soluble poly(l,d-lactide) (PLDLA-SOL) present in the hybrid was investigated for a better understanding of the conflicting roles of LDH in polymerization and degradation of PLDLA-SOL. High molecular mass PLDLA-SOL is obtained through initiation of polymerization by LDH. However an additional insoluble organic–inorganic fraction, INSOL, is also observed within the product when PLDLA-SOL is extracted using methylene chloride as solvent. It is proposed that INSOL is an ionomeric network comprising hydrogen-bonded, or otherwise co-ordinated, lactic acid monomer salts of magnesium, together with PLDLA in a 24%–76% mass ratio.

The water soluble composite poly(vinylpyrrolidone–methylaniline): A new class of corrosion inhibitors of mild steel in hydrochloric acid media

In recent years poly methyl aniline has been reported as one of the efficient corrosion inhibitors of mild steel in acidic media. In view of the major limitation of the insolubility of polymethyl aniline PMA, we propose to convert PMA into a water soluble composite using supporting polymer polyvinylpyrrolidone to get higher solubility and corrosion inhibition efficiency. The water soluble composite poly(vinylpyrrolidone-methyl aniline) was synthesized by chemical oxidative polymerization and its inhibitive effect on mild steel in 1M HCl has been investigated using weight loss and electrochemical techniques (potentiodynamic polarization studies and impedance spectroscopy). SEM and EDX analyses are carried out to establish a protective film formation on the metal surface.

Fabrication of Water Soluble Conjugated Polymers for WOLED

Recently, the novel organic materials for white OLEDs have been researched, but it is not easy to apply polymers to WPLEDs. However, because water soluble conjugated polymers can be spin-coated on organic soluble conjugated polymers, when organic soluble blue and red emission polymers, and water soluble green emission polymer were used as multi-layer device, WPLEDs can be produce by the total color of self emission at multi-layer. Water soluble anionic poly(9,9-bis(4′-sulfonatobutyl)fluorene-co-alt-1,4-phenylene) (anion-PF(Na+)) was synthesized, and we investigated the white color emission by multi-layer of this class of anionic conjugated polyelectrolytes and organic conjugated polymers (MEH-PPV) using the following device structure: ITO/PEDOT:PSS/anion-PF(Na+)/MEH-PPV/Al, because anionic PFP can get the self-blue emission and green emission by aggregation effect in film condition. Finally, the color of devices made using different device structure of ITO/PEDOT:PSS/MEH-PPV/anion-PF(Na+)/Al was compared, and this device can get the blue and red emission because the green emission of anionic PFP was absorbed in MEH-PPV.

Studies on Synthesis and Effect of Dopants on Conductivity and Morphology of Organically Soluble Poly(o-anisidine)

Synthesis of poly(o-anisidine) doped with various protonic acids by using ammonium persulphate as oxidizing agent were carried out in aqueous acid media. Influences of protonic acids on the physicochemical properties were investigated. The various process parameters were optimized to obtain poly(o-anisidine) in the conducting salt phase form. The results are discussed with references to different protonic acids. It was observed that poly(o-anisidine) is highly soluble in organic solvents, such as m-cresol and N-methyl pyrrolidinone (NMP). The polymers were characterized by UV-Visible, FTIR, SEM, XRD and conductivity measurements. A result shows that, different types of dopant acids HCl, H2SO4 and HClO4 affect the morphology and electrical conductivity of the polymer. The electrical conductivity of the polymer follows the order HCl >H2SO4>HClO4. Thus the effect of dopant ion type and the size of its negative ions influence the physico-chemical properties. UV-Vis absorption spectra shows peaks at 740–783 nm with shoulder at 380–420 nm as characteristic peaks for the emeraldine salt (ES) phase of poly(o-anisidine) POA. The FTIR spectra show a broad and intense band at ∼2800–3001 cm−1 and ∼1159–1170 cm−1 that account for the formation of ES phase of the polymer. The X-ray diffraction spectra show a characteristic peak at 20–30o, 2θ range which reveals partial crystalline structure. The conductivity of the poly(o-anisidne) salt was found to be in the range of 10−3 to 10−2 S/cm. SEM studies of poly(o-anisidine) doped with HCl shows the continuous granular uniform morphology with sub-micrometer evenly distributed particles of size ∼100–200 nm.

Covalently crosslinked chitosan-poly(ethylene glycol) hybrid hydrogels to deliver insulin for adipose-derived stem cells encapsulation

Biodegradable hydrogels carrying adipose-derived stem cells (ASCs) have been highlighted with promising potential regarding adipose tissue engineering. In this study, covalently crosslinked natural/synthetic hybrid hydrogels were prepared from methacrylated water soluble chitosan (N-succinyl-chitosan, SCS) and poly(ethylene glycol) (PEG) by photoinitiaing polymerization under the existence of Irgacure 2959 and the irradiation of UV light. The effect of the incorporated PEG on the in vitro morphologies, equilibrium swelling, weight loss and compressive modulus of SCS/PEG hybrid hydrogels in phosphate buffered saline (PBS) at 37 °C were studied. In order to evaluate the ability of hydrogels to effectively deliver the adipogenic factor, insulin was entrapped within hydrogels by copolymerizing methacrylated SCS/PEG. The insulin would be released from the hydrogels into the local microenvironment via the controlled weight ratio of SCS/PEG. Results demonstrated that the hybrid hydrogel with 10 wt% PEG showed a higher efficiency of insulin delivery compared to the control hydrogels. ASCs were seeded into the insulin-loaded SCS/PEG hydrogels in vitro to assess the biological performance and applicability of hydrogels as cell carriers. These characteristics provide potential opportunities for the hybrid SCS/PEG hydrogels as injectable scaffolds in soft tissue engineering applications. Open image in new window

PREPARATION OF CHITIN NANOFIBERS-GOLD METALLIC NANOCOMPOSITE BY PHASE TRANSFER METHOD

Chitin nanofibers (CNFs)- Au(0) nanoparticles ( Au NPs) blends in dispersion, flakes and thin film or sheet forms were first prepared by mixing pre-organized Au NPs prepared in triblock copolymer with diluted CNFs suspension. Water soluble polymer triblock copolymer poly (methyl vinyl ether, PMVE) in the amount 0.6 wt.% was used to prepare NPs and 0.12 wt.% net chitin content was used as CNFs suspension to prepare the blended composite. Au NPs of size 4.4 nm (σ = 1.2) were obtained when Au salt ( HAuCl4⋅3H2O (hydrogen tetrachloroaurate (III) trihydrate) was reduced by 5 equivalents of NaBH4 . PMVE polymer acted as a stabilizing or capping agent for pre-organized NPs. Completion of reaction was fast, all salt reduced to metallic form in just 15 min after the addition of NaBH4 . CNFs (1 wt.% chitin) which was used to prepare CNFs- Au NPs blend composite were prepared from crab shell in never dried acidic condition by established combination of chemical and mechanical processes that gave 25–40 nm width and high aspect ratio CNFs. When polymer capped Au NPs mixed with CNF suspension, all Au NPs and 56% polymer were mass transferred from water phase to entangle with more polar moieties of CNFs-water suspension as no trace of Au NPs were noticed in water–polymer mother liquor after blending with CNFs suspension. Particles size of CNFs- Au NPs composite was measured by employing TEM, SAXS and SEM techniques. CNFs- Au NPs composite were characterized in solution and compressed dried sheet form by recording digital images, UV-vis and XRD spectroscopies. CNFs- Au NPs suspension had antibacterial activity against gram positive bacteria S. aureus.

Structure–property relationships of soluble poly(2,5-dibutoxyethoxy-1,4-phenylene-alt-2,5-thienylene) (PBuPT) for organic-optoelectronic devices

In this work, we have analyzed the vibrational, optical and emission properties of soluble copolymer denoted poly(2,5-di-butoxyethoxy-1,4-phenylene-alt-2,5-thienylene) (PBuPT) by combining experimental and theoretical studies. Extrapolated Ionization Potentials (IPs), Electron Affinities (EAs) and energy gaps were determined employing Density Functional Theory (DFT) method. Theoretical analyses havebeen performed in order to understand deeply the interesting role played by the intra-molecular S⋯O interactions in determining the planarity of the copolymer. Further, an intra-molecular charge transfer for the copolymer has been proposed through the alternating donor–acceptor conjugated systems. In addition, vibrational, optical and emission spectra of three repeat units model compound have been simulated and compared to the experiments. Based on these results, we have described attentively the structure–property relationships of those samples which could be exploited as an active layer in organic optoelectronic devices.

Conjugated Polymer Consisting of Quinacridone and Benzothiadiazole as Donor Materials for Organic Photovoltaics: Coplanar Property of Polymer Backbone

Highly soluble poly[quinacridone-alt-benzothiadiazole] (PQCDTB) has been synthesized through the Suzuki coupling reaction by introducing planar quinacridone and highly absorbing benzothiadiazole. The PQCDTB dissolved in general organic solvents, and the Mn was 49.8 kg/mol. The optical band gap energy was 1.92 eV, which was similar to the band gap of benzothiadiazole. The HOMO and LUMO levels of PQCDTB were −5.24 eV and −3.32 eV, respectively. According to the XRD measurement, PQCDTB showed the formation of ordered lamellar structure as an out-of-plane peak (h00) by the alkyl side chain of quinacridone and conventional edge-on π- stacking. This study also evaluated the OPV characteristics by fabricating a bulk-heterojunction–type polymer solar cell. When PQCDTB and PC71BM were fabricated in a 1:1 weight ratio, the open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and power conversion efficiency (PCE) were 0.79 V, 5.6 mA cm–2, 55.8% and 2.5%, respectively. In particular, PQCDTB exhi...

Study of the electrochemical behavior at low temperatures of green anodes for Lithium ion batteries prepared with anatase TiO2 and water soluble sodium carboxymethyl cellulose binder

The electrochemical behavior at low temperatures of anatase TiO2 electrodes for Lithium ion batteries have been evaluated by galvanostatic cycles in the temperature range 20 to −30°C. Two different manufacturing processes have been used to prepare anatase anodes containing water soluble sodium carboxymethyl cellulose (CMC) or poly(vinilydene fluoride) (PVDF) as binder.The low temperature performances at different charge/discharge rates of TiO2/CMC and TiO2/PVDF electrodes are compared and discussed in terms of irreversible capacity loss (ICL) at the first cycle, capacity retention and reversible capacity. The kinetics of the electrodes containing CMC or PVDF is evaluated by Electrochemical Impedance Spectroscopy.

Nanosized palladium-catalyzed Suzuki–Miyaura coupling polymerization: synthesis of soluble aromatic poly(ether ketone)s

Nanosized palladium species, which were prepared in situ from Pd(OAc)2, PPh3 and Bu4NOAc in 1,4-dioxane, were suitable for the synthesis of 1,1′-binaphthyl-2,2′-dioxy-bearing aromatic poly(ether ketone)s 5. The resulting poly(ether ketone)s 5 are soluble in typical organic solvents, such as CHCl3, tetrahydrofuran and N,N-dimethylformamide. Glass transition temperatures (Tg′s) of poly(ether ketone)s 5 are in the range of 188–224 °C. Temperatures where 10% weight losses of poly(ether ketone)s 5 occur under N2 flow are in the range of 445–480 °C.