Polymers P1 P3 Research Articles

Synthesis and Physicochemical Properties of Thermally Sensitive Polymeric Derivatives of N-vinylcaprolactam.

Six derivatives of poly-N-vinylcaprolactam (PNVCL) P1-P6 were synthesized via surfactant-free precipitation polymerization (SFPP) at 70 °C, with potassium persulfate (KPS) as the initiator. P5 and P6 were synthesized using the cross-linker N,N'-Methylenebisacrylamide (MBA). The conductivity was measured to monitor the polymerization process. The hydrodynamic diameters (HDs) and polydispersity indexes (PDIs) of aqueous dispersions of P1-P6 were determined using dynamic light scattering (DLS) and zeta potential (ZP) using electrophoretic mobilities. At 18 °C for P1-P6, the HDs (nm) were 428.32 ± 81.30 and PDI 0.31 ± 0.19, 528.60 ± 84.70 (PDI 0.42 ± 0,04), 425.96 ± 115.42 (PDI 0.56 ± 0.08), 440.34 ± 106.40 (PDI 0.52 ± 0.09), 198.39 ± 225.35 (PDI 0.40 ± 0.19), and 1201.52 ± 1318.05 (PDI 0.71 ± 0.30), the and ZPs were (mV) 0.90 ± 3.23, -4.46 ± 1.22, -6.44 ± 1.82, 0.22 ± 0.48, 0.18 ± 0.79, and -0.02 ± 0.39 for P1-P6, respectively. The lower critical solution temperature ranged from 27 to 29 °C. The polymers were characterized using the ATR-FTIR method. The study concluded that the physicochemical properties of the product were significantly affected by the initial reaction parameters. Polymers P1-P4 and P6 have potential for use as drug carriers for skin applications.

Side chain engineering of fluorinated benzothiadiazole‐based polymers: Improving the charge transport in organic field‐effect transistors

AbstractThree donor‐acceptor (D‐A) polymers P1–P3 are designed and synthesized, with 4,7‐dibromo‐5,6‐difluorobenzo[c][1,2,5]thiadiazole (FBT) as A and thiophene derivatives as D. All polymers show good thermal stability. The UV–vis absorption spectra show that P1 has too strong aggregation in solution, and it has no obvious temperature‐dependent aggregation (TDA) performance, which is also revealed in the variable temperature UV–vis absorption spectra. P2 film shows the same aggregation as in solution, P3 film shows stronger aggregation than that in solution. Polymers P1 and P2 both have strong TDA properties. Organic field effect transistors (OFETs) are prepared based on polymers P1, P2, and P3. OFETs devices prepared with high molecular weight polymers have better performance, and the polymer with 2‐nonyltridecyl side chain leads to the highest hole mobility around 0.252 cm2 V−1 s−1. The results show that the application of high molecular weight polymers and the selection of appropriate side chains are very important for the charge transport performance of OFETs.

Optoelectronic and DFT investigation of thienylenevinylene based materials for thin film transistors

• Tuning the monomeric constituents of a polymeric semiconductor. • Tailoring the structural and performance for OFETs application. • Material’s properties and OFETs device performance is determined. • Top Gate/Bottom Contact OFET device is fabricated. • P-type characteristics were observed with P3 maximum mobility of 0.0136 cm 2 V −1 s −1 . Tuning the monomeric constituents along the backbone of a polymeric semiconductor has been quite exploited in altering the photophysical properties of functional materials. Despite this, electron accepting unit alteration schemes have seldomely been utilized in tailoring the structural and performance feature of these moieties especially for OFETs application. Herein, we modulate the acceptor composition within a π-conjugated semiconductor through simple random co-polymerization reaction to obtain resulting terpolymers and assess their structural modification on the material’s properties and OFETs device performance. Synthesized polymers P1-P3, demonstrated tenuous changes in their optoelectronic properties. In an encapsulated Top Gate/Bottom Contact OFET device, a P-type characteristics were observed with P3 terpolymer demonstrating a comparatively better maximum mobility of 0.0136 cm 2 V −1 s −1 .

A Supramolecular Hydrogel Based on Copolymers of Acrylic Acid and Maleic Anhydride Derivatives with Terpyridine Motifs.

A kind of terpyridine derivative (NH2-Tpy) in which the amino was incorporated by a short alkyl chain was synthesized. Through grafting of terpyridine units into the hydrophilic copolymers of maleic anhydride and acrylic acid PAAMa via the reaction of the amino groups in NH2-Tpy and the maleic anhydride units, a series of gelator polymers—P1, P2, and P3—containing different contents of terpyridine units was synthesized. Under coordination of Ni2+ and terpyridine ligands in linear polymers, the supramolecular hydrogels H1, H2, and H3 with different cross-linking degrees were prepared. The linear polymers P1–P3 had a strong absorption peak at about 290 nm in the UV-vis spectra which was attributed to π–π* transition, and there was a new peak at about 335 nm led by the metal-to-ligands charge transfer (MLCT) when coordinated with Ni2+ ions. According to the rheological behaviors, the storage modulus (G′) was larger than the loss modulus (G′′). These hydrogels showed typical gel-like characteristics when the terpyridine content of the hydrogels exceeded 10%, and the hydrogels showed liquid-like characteristics when the terpyridine content of the hydrogels was less than 7%. The results of the micromorphological investigation of the xerogels from SEM illustrated the metal–terpyridine coordination cross-linking could have an important influence on the microstructures of the resulting hydrogels. Furthermore, these hydrogels based on supramolecular cross-links exhibited reversible solution–gel transition at different environmental temperatures. At the same time, the equilibrium swelling of the supramolecular hydrogels was 8.0–12.3 g/g, which increased with the decrease in the content of the terpyridine units in the resulting hydrogels.

Realizing External Quantum Efficiency over 25% with Low Efficiency Roll-Off in Polymer-Based Light-Emitting Diodes Synergistically Utilizing Intramolecular Sensitization and Bipolar Thermally Activated Delayed Fluorescence Monomer

Realizing External Quantum Efficiency over 25% with Low Efficiency Roll-Off in Polymer-Based Light-Emitting Diodes Synergistically Utilizing Intramolecular Sensitization and Bipolar Thermally Activated Delayed Fluorescence Monomer

Formation of reactive isocyanate group-containing polymers via Lossen rearrangement

We report an efficient and phosgene-free method for the synthesis of isocyanate group (NCO)-containing polymers via Lossen rearrangement. The key monomer of N-acetoxymethacrylamide (AMAA), possessing N-acetoxy amide (AA) group was synthesized from the reaction of N-hydroxymethacrylamide (MHA) with acetic anhydride. By adjusting the feed ratio of methyl methacrylate (MMA) and AMAA, a series of AA-containing polymers (P1-P3) were prepared by free-radical polymerization. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) revealed that the AA groups in polymers P1-P3 can be readily converted to isocyanate groups by heating at 130 ℃ to afford the NCO-containing polymers P4-P6 with conversion percent of 60, 77 and 78, respectively. Furthermore, the AA-containing polymers can be used as a latent NCO-containing polymer for further chemical modification, such as in-situ grafting reaction with hydroxyl compounds. The spectroscopic analyses confirmed that the dye functional group of disperse red 1 (DR1) was successfully grafted on either NCO- or AA-containing polymers.

Synthesis of folded H-stacking skipped π polymers consisting of different 2-substituted trimethylene tethering units and their optical and conductive property

A series of polymers P1–P4 ([–CH2CH(Z)CH2–(π conjugated unit)–]n, where Z = a bulky substituent) were synthesized via the Suzuki–Miyaura coupling polymerization and predominantly existed in their folded H-stacking form in the solution and film, which was evidenced by ultraviolet absorption, fluorescent behavior, and X-ray diffraction analysis. The morphology of the polymers in the solid states was dependent on the structure of the Z group present. The conductive nature of P1–P4 was preliminarily demonstrated on hole-only devices. Moreover, a similar onset voltage was observed for P1–P3, which all contained the same π units; however, their current–voltage characteristics were highly dependent on the Z structure. P4, which contained cross-conjugated π units, exhibited a relatively high conductivity with a lower onset requirement.

Synthesis of Conjugated Copolymer Containing Spirobifluorene Skeleton by Acyclic Diene Metathesis Polymerization for Polymer Light‐Emitting Diode Applications

Grubbs‐type, Hoveyda‐type, cyclic alkyl amino carbene (CAAC)‐based ruthenium olefin metathesis catalysts were used for the acyclic diene metathesis (ADMET) polymerization of 2,7‐divinyl‐9,9‐di‐n‐octylfluorene (DVF). Additionally, various ratios of DVF and 2,2′,7,7′‐tetravinyl‐9,9′‐spirobifluorene (TVSF) were subjected to ADMET polymerization to obtain polymers P1–P7. Polymers P1–P4 were analyzed with gel permeation chromatography, UV–vis spectroscopy, and photoluminescence spectroscopy. As the TVSF ratio increases, polymers exhibit lower solubility but a narrower band in the photoluminescence spectrum. Polymer light‐emitting diode (PLED) devices were fabricated with polymers P1, P2, and P3. The performances of the PLED devices indicated that polymers including more spirobifluorene blocks showed better turn‐on voltage, brightness, current efficiency, and power efficiency.

Enhanced performance of ternary polymer solar cells via property modulation of co-absorbing wide band-gap polymers

A new approach is presented here to maximize the efficiency of ternary blend polymer solar cells (ter-PSCs). The properties of co-absorbing wide band-gap polymers are fine-tuned via the insertion of two different appropriate electron-acceptor units on their backbone in different ratios, and the resulting polymers are utilized as a co-absorbent on ter-PSCs. The copolymerization of benzodithiophene, pyrrolopyrrole-1,3-dione, and difluoro-benzothiadiazole derivatives at three different ratios, 1.00:1.00:0.00, 1.00:0.50:0.50, and 1.00:0.25:0.75, produces the polymers P1–P3. The absorption bands of P1–P3 are gradually red-shifted, and the band-gaps are reduced. The crystallinity of the polymers is increased in the order of P1 < P2 < P3. The binary polymer solar cells (bi-PSCs) are fabricated using blends of P1, P2, or P3 with PC70BM and provide comparable power conversion efficiencies (PCEs) of 5.41%, 5.55%, and 4.01%, respectively. However, the inclusion of 20 wt% of each of P1, P2, and P3 on a P4 (=PTB7-Th):PC70BM blend offers PCEs of 9.31%, 9.60%, and 9.85%, respectively, which are higher than that of the bi-PSC made using a blend of P4:PC70BM (PCE = 8.20%). The improved absorption, crystallinity, and carrier mobilities of the ternary blends are the main reasons for their enhanced photovoltaic performance compared with the binary blends.

Donor-Acceptor-Donor Copolymers with 3,4-Ethylenedioxythiophene Moiety: Electropolymerization and Effect on Optoelectronic and Electrochromic Properties.

Three random copolymers PE-co-M1, PE-co-M2, and PE-co-M3 were obtained by electrochemical polymerization of donor–acceptor–donor monomers M1, M2, and M3 with 3,4-ethylenedioxythiophene moiety, respectively, using a 1:1 molar ratio of the corresponding monomers, to find new properties and a more effective way to control the optoelectronic properties in conjugated system. For comparison purpose, polymers P1, P2, and P3 were prepared from the corresponding monomer units M1–M3, respectively, by electrochemical polymerization. We also present efficient synthesis, characterization, and comparative density functional theory (DFT) calculations of the monomers M1–M3 and polymers P1–P3. Cyclic voltammetry, spectroelectrochemistry, and electrochromic properties of all of the polymers P1–P3 and copolymers PE-co-M1, PE-co-M2, and PE-co-M3 were carried out and a throughout comparison was made. We have shown that electrochemical copolymerization is a powerful strategy to tune the highest occupied molecular orbital energy level, band gap, and color of the copolymer. Thus, this finding clearly indicates that the copolymers show significantly different optoelectronic properties compared to their constituent polymers.

Investigation of Photophysical Properties on Carbazole and Pyrazine Based Conjugated Polymer: Excellent Fluorescence Sensing Towards to Cadmium Ion

Developing fluorescent sensor is most advantages in recent years to detect metal ions from biological and environmental systems. Hence, three new donor (carbazole)–acceptor (pyrazine) conjugated polymers (P1–P3) were synthesized by Wittig route. The polymers was structurally confirmed using FTIR, NMR spectroscopy and expressed excellent emission behavior (480–520 nm) towards various polarity of the solvents. Luminescent quantum yield of the polymers P1–P3 were 0.64, 0.69, and 0.72 in chloroform with optical band gap of 2.13, 2.10, and 2.06 eV respectively. Excellent thermal stability with an onset decomposition temperature of P1–P3 was 320, 340, and 200°C under nitrogen atmosphere. Cyclic voltammetry results depicted that the LUMO and HOMO was 3.41 to 3.45 eV and–5.72 to–5.65 eV respectively. Spherical and rod shaped surface morphology of the polymer thin film has been observed from AFM technique. The fluorescence sensitivity of the polymers has been detected towards to Cd2+ ion and its ability of the limit of detection (LOD) was found to be (0.8–1.3) × 10–5 M. This kind of cadmium ion sensing fluorescent polymer probe is highly useful for biomedical applications.

Functional Poly(ester–amide)s with Tertiary Ester Linkages via the Passerini Multicomponent Polymerization of a Dicarboxylic Acid and a Diisocyanide with Different Electron-Deficient Ketones

We describe a straightforward synthetic strategy for a new family of functional poly(ester–amide)s (PEAs) with tertiary ester linkages via the Passerini multicomponent polymerization (Passerini-MCP) of a diacid (A2), 1,6-diisocyanohexane (B2), and four kinds of electron-deficient ketones. First, Passerini three-component reactions (Passerni-3CR) of hexanoic acid and tert-butyl isocyanide with nine kinds of ketones were investigated to evaluate the reactivities of these ketones toward Passerni-3CR. Four electron-deficient ketones, 1,1,1-trifluoroacetone (1), 1,1,1-trifluoroacetophenone (2), ethyl pyruvate (3), and 2,3-butanedione (4), were found to be excellent oxo-compounds for this Passerini-3CR. Then, the Passerini-MCP of A2 and B2 with 1, 2, 3, and 4 in CH2Cl2 was performed to generate polymers P1–P4 with tertiary ester linkages and different electron-withdrawing substituents. Polymer P5 was also prepared by the Passerini-MCP of A2 and B2 with phenylacetaldehyde (5) for comparison. Size exclusion chrom...

Phenanthrodithiophene (PDT)–Difluorobenzothiadiazole (DFBT) Copolymers: Effect on Molecular Orientation and Solar Cell Performance of Alkyl Substitution onto a PDT Core

Synthesis, characterization, and solar cell application of three 4,7-dialkylated phenanthro[1,2-b:8,7-b′]dithiophene (PDT)–difluorobenzothiadiazole (DFBT copolymers (P1–P3) with different linear alkyl side chains to improve solubility, molecular weight, and molecular orientation are described. The utilization of Ir-catalyzed direct borylation and sequential functionalization can selectively afford the target 4,7-dialkylated PDT as the monomers. Migita–Kosugi–Stille coupling in the presence of CuI can accelerate polymerization to afford high-molecular-weight polymers along with their improved solubility. The effect of alkyl substitution at the 4,7-positions on the electronic structure of PDT–DFBT copolymers is negligible. By installation of additional alkyl chains at the 4,7-positions of PDT, the synthesized polymers P1–P3 have lower intermolecular interaction than that of nonalkylated P0, but they still maintained aggregation behavior in solution. In addition, they formed a favorable face-on orientation w...

Polymersomes from hybrid peptide-based bottlebrush homopolymers

A series of compounds, in which exo-norbornene scaffold appended with amino acids, was synthesized. These compounds underwent ring opening metathesis polymerization (ROMP) catalyzed by Grubbs second generation ruthenium catalyst to form polymers with bottlebrush architecture. Four different polymers P1-P4 were synthesized, differing in number of lipid units and degree of branching. These polymers were well-characterized by 1H NMR and gel permeation chromatographic (GPC) techniques. These peptide-based homopolymers showed an exceptional ability to self-assemble to form polymersomes. The self-assembled structures were characterized by various ultramicroscopic techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The entrapment capability of polymer vesicles was confirmed by dye-encapsulation studies.

Design and synthesis of N-substituted perylene diimide based low band gap polymers for organic solar cell applications.

In this study, we report on the synthesis and device studies of a series of new copolymers containing N-substituted perylene dimide and dioctylfluorene units as part of the main backbone. A facile synthetic approach avoiding non-selective bromination was used to synthesize the monomer M1 by the reaction of perylene-3,4,9,10-tetracarboxylic dianhydride with 2-amino-7-bromo-9,9-dioctylfluorene. The copolymers P1 and P2 were synthesized by Suzuki polycondensation of M1 with 2,2′-(9,9-dioctyl-9H-fluoren-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) M2 and 9-(heptadecan-9-yl)-2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole M3, respectively. The copolymer P3 was synthesized by direct arylation polymerization of M1 with 4,7-bis(4-octylthiophen-2-yl)benzo[c]-1,2,5-thiadiazole M4. All the copolymers showed thermal stability greater than 380 °C as evidenced from thermogravimetric analysis. The copolymers exhibited a narrow optical band gap (1.80–2.08 eV) with their UV-visible absorption spectra extending up to the NIR region and they are found to be suitable for use in OSC applications. The molecular weights of the polymers P1–P3 were found to be in the range of 10.68 to 16.02 kg mol−1 as measured from GPC analysis. The surface morphology of the active layers based on P1/P2/P3:P3HT blend films was investigated by AFM and the rms values from height images range from 0.65 to 2.90 nm. The polymers were blended with P3HT to fabricate BHJ solar cells in three different weight ratios i.e. 1 : 1, 1.5 : 1 and 2 : 1 and the best power conversion efficiency was observed for the binary film of P3:P3HT blend device in a 1 : 1 weight ratio which reached up to 1.96% with a Voc of 0.55 V, Jsc of 10.12 mA cm−2 and FF of 34.63% which is among the highest reported for BHJ solar cells with N-substituted PDI based acceptors.

Nonconventional Fluorescent Polynorbornenes Bearing Aminosuccinimide Side Groups

AbstractIn this contribution, a new class of fluorescent polynorbornenes containing side chains that homogeneously decorated with aminosuccinimide side groups as nonconventional chromophores is introduced. First of all, monomers M1–M3 are synthesized in an efficient and straightforward fashion by means of Michael addition between three kinds of alkyl amines and monomer precursor 1, a compound containing norbornene (polymerizable group) and maleimide (Michael acceptor) groups. Subsequently, ring‐opening metathesis polymerization of M1–M3 is conducted to generate polymers P1–P3 with high molecular weights (Mn values exceeding 9800) and narrow molecular weight distributions (Ð values no more than 1.20), respectively. Quantitative conversion of monomers and microstructural integrity of polymers are verified in all cases. Finally, thermal stability, glass transition behavior, wettability, and optical properties of polymers P1–P3 are investigated. In particular, this new class of fluorescent polymeric materials exhibits blue emission (470–478 nm) under UV irradiation with large Stokes shifts (over 110 nm).

Hypercrosslinked silole‐containing microporous organic polymers with N‐functionalized pore surfaces for gas storage and separation

ABSTRACTNovel hypercrosslinked microporous organic polymers (MOPs) derived from N‐functionalized siloles as basic building units have been designed and synthesized via Friedel–Crafts alkylation reaction. The resulting N‐functional silole‐containing polymer networks exhibit high thermal stabilities and moderate Brunauer–Emmett–Teller surface area ranging from 666 to 1137 m2 g−1. The incorporation of carbazole or triphenylamine moieties into the polymer skeleton increases the number of electron donating basic nitrogen sites in the porous frameworks. Thus, the corresponding polymer PDMCzS shows enhanced CO2 adsorption capacities of 3.23 mmol g−1 at 273 K and 1.13 bar, and higher CO2/N2 selectivity (43.99) at 273 K than the analogous silole‐containing polymers P1–P3. These results demonstrated that the N‐functionalized silole‐containing polymer network is a very promising candidate for potential applications in post‐combustion CO2 capture and sequestration. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45907.

Single-junction fullerene solar cells with 10% efficiency and high open-circuit voltage approaching 1 V

It has been proven that the introduction of F atom and the replacement of alkyl side-chain with alkylthio substituent could be the effective side-chain strategies, to obtain the deep highest occupied molecular orbital (HOMO) energy level with little influence on the optical absorption, and in turn, the small photo energy loss (Eloss). In this work, we combine the advantages of D–A(π)–Q–A(π) strategy and the above side chain engineering, to construct a series of high-performance polymers P1-P3 with high open-circuit voltage (VOC) of exceeding 0.90V in the conventional solar cells. Meanwhile, small Elosss of 0.73–0.78eV are achieved accompanying high VOC and almost unchanged optical bandgaps of ~ 1.70eV, which are the smaller values in comparison with that of the other high-performance polymer systems. More encouragingly, P2-based solar cells exhibit high PCE of 10.30% and VOC of 0.97V, which is one of the highest values for polymer/fullerene based solar cells. Our work not only demonstrates a series of high-efficiency new materials, but also strongly confirms that the combination of D–A(π)–Q–A(π) arrangement and rational side chain engineering is a very promising strategy to construct high-performance photovoltaic polymers with reduced energy loss.

Marriage of ring-opening metathesis polymerization and thiol-maleimide chemistries: Direct polymerization of prefunctionalized monomers or postpolymerization modification?

Two distinct synthetic methodologies to furnish polynorbornene bearing thiol-maleimide adduct side groups, namely direct ring-opening metathesis polymerization (ROMP) of prefunctionalized monomers and postpolymerization modification, were investigated and compared in this study. ROMP of thiol-maleimide adduct-containing monomers M1-M4 was performed to yield polymers PM1-PM4 with full conversion of monomers but broad molecular weight distribution. Meanwhile, narrowly distributed polymers P1-P4 were generated through postpolymerization modification of polymer P0 by using thiol-maleimide reaction. However, removal of residual monomer M0 was an indispensable step prior to postpolymerization modification since incomplete monomer conversion was observed in the previous step, synthesis of polymer P0 using ROMP of maleimide-containing monomer M0. Narrow molecular weight distribution in conjunction with good polymerization controllability renders the strategy of postpolymerization modification a seemingly more reliable synthetic protocol to achieve the goal of this contribution. Finally, polymers P0-P4 were subjected to property studies to elucidate their thermal stability, glass transition behavior, wettability and gelation using thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), water contact angle measurement, and cross-linking test, respectively.

Postpolymerization modification of polynorbornene side chains via tetramethyl guanidine promoted esterification

ABSTRACTWe demonstrate that polynorbornene containing primary activated bromide moieties is a novel chemically modifiable platform for postpolymerization modification. Polymer P0 was synthesized via ring‐opening metathesis polymerization of monomer 1 with the assistance of Grubbs third generation (G‐III) catalyst. Subsequently, nucleophilic substitution was conducted by mixing P0 with n‐caproic acid, sorbic acid, m‐toluic acid or 4‐nitrobenzoic acid in the presence of 1,1,3,3‐tetramethylguanidine (TMG) under mild and stoichiometric condition to generate functionalized polymers P1–P4. NMR results approved full conversion of the reactive sites and exemplified the “click” nature of TMG promoted esterification. Thermal stability and glass transition behaviors of all the polymer samples were investigated by thermal gravimetric analysis and differential scanning calorimetry. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3733–3740