Monomers 1a Research Articles

Enhancing corrosion resistance and toughness of solvent-free epoxy coatings with low-viscosity fluorine-containing hyperbranched polyether

In this study, a low-viscosity epoxy-terminated fluorine-containing hyperbranched polyether (FHBPE) was synthesized and incorporated in a solvent-free epoxy coating formulation to enhance coating toughness and corrosion resistance while minimizing the impact on coating viscosity. FHBPE was synthesized by a solvent-free one-pot method with hexafluorobisphenol A (A2 monomer) and trimethylolpropane triglycidyl ether (B3 monomer). Subsequently, FHBPE, E51 epoxy resin, and an alicyclic amine curing agent were blended to create the solvent-free epoxy coating, which was applied onto a steel substrate by a scraping coating method. This research demonstrates that addition of FHBPE did not show adverse effect on coating viscosity; instead, it reduced the viscosity at around 6 wt% loading. The epoxy-terminated FHBPE increased the cross-linking density of neat E51 coating by up to 20.7 %. Furthermore, the introduction of flexible segments enhanced the toughness, leading to a one-grade increase in the coating flexibility from 1 to 0.5 mm. Furthermore, FHBPE significantly improved the corrosion resistance of the coatings, attributed to increased cross-linking density and hydrophobic properties of the coating. Among FHBPE-modified coatings, the coating with 6 wt% loading demonstrated superior overall performance. Over a 60-day immersion period, its electrochemical impedance value remained stable, while the neat E51 coating experienced a two-orders-of-magnitude decrease. Furthermore, the 6 wt% FHBPE-modified coating passed the 750-h salt spray test without obvious rust, outperforming the neat E51 coating (200 h). This study presents a feasible and promising strategy for the formulation design and mass production of solvent-free epoxy coatings.

Oligomeric phloroglucinols with hAChE inhibitory and antibacterial activities from tropic Rhodomyrtus tomentosa

Alzheimer’s diseases (AD) and other infectious diseases caused by drug-resistance bacteria have posed a serious threat to human lives and global health. With the aim to search for human acetylcholinesterase (hAChE) inhibitors and antibacterial agents from medicinal plants, 16 phloroglucinol oligomers, including two new phloroglucinol monomers (1a and 1b), four new phloroglucinol dimers (3a, 3b, 4b, and 5a), six new phloroglucinol trimers (6a, 6b, 7a, 7b, 8a, and 8b), and two naturally occurring phloroglucinol monomers (2a and 2b), along with two known congeners (4a and 5b), were purified from the leaves of tropic Rhodomyrtus tomentosa. The structures and absolute configurations of these new isolates were unequivocally established by comprehensive analyses of their spectroscopic data (NMR and HRESIMS), ECD calculation, and single crystal X-ray diffraction. Structurally, 3a/3b shared a rare C-5′ formyl group, whereas 6a/6b possessed a unique C-7′ aromatic ring. In addition, 7a/7b and 8a/8b were rare phloroglucinol trimers with a bis-furan and a C-6′ hemiketal group. Pharmacologically, the mixture of 3a and 3b showed the most potent human acetylcholinesterase (hAChE) inhibitory activity with an IC50 value of 1.21 ± 0.16 μM. The molecular docking studies of 3a and 3b in the hAChE binding sites were performed, displaying good agreement with the in vitro inhibitory effects. In addition, the mixture of 3a and 3b displayed the most significant anti-MRSA (methicillin-resistant Staphylococcus aureus) with MIC and MBC values of both 0.50 μg/mL, and scanning electron microscope (SEM) studies revealed that they could destroy the biofilm structures of MRSA. The findings provide potential candidates for the further development of anti-AD and anti-bacterial agents.

Non-stoichiometric effect in the superacid-catalyzed polyhydroxyalkylation of biphenyl and 1-propyl isatin

An experimental study on the superacid-catalyzed polyhydroxyalkylation of biphenyl (A2 monomer) and 1-propyl isatin (B2 monomer) at non-stoichiometric conditions is presented. The produced high-performance polymers were characterized by gel permeation chromatography matrix-assisted laser-desorption/ionization-time-of-flight (MALDI-TOF), nuclear magnetic resonance and diffusion-ordered spectroscopy (DOSY). High molecular weights (Mw > 150,000 Da) and ultra-high molecular weights (Mw ∼ 900,000 Da) are obtained when B2 is used in excess, which agrees with the behavior observed at non-stoichiometric conditions for other superacid catalyzed polyhydroxyalkylations, contrary to the case when A2 is used in excess, where a reduction in molecular weight is obtained, as reported in a previous study from our group. A, B, and M types of linear polymer molecules, as well as C-type cycles, were observed from the MALDI-TOF data.

Preparation of Efficient Organic Solar Cells Based on Terpolymer Donors via a Monomer-Ratio Insensitive Side-Chain Hybridization Strategy.

Creating new donor materials is crucial for further advancing organic solar cells. Random terpolymers have been adopted to overcome shortcomings of regular alternating donor-acceptor (D-A) polymers of which the performance is often susceptible to batch-to-batch variations. In general, the properties and performance of efficient D1 -A-D2 -A and D-A1 -D-A2 terpolymers are sensitive to the D1 /D2 or A1 /A2 monomer ratios. Side-chain hybridization is a strategy to address this problem. Here, six D1 -A-D2 -A-type random terpolymers comprising D1 and D2 monomers with the same π-conjugated D unit but with different side chains were synthesized. The side chains, containing either fluorine or trialkylsilyl substituents were chosen to provide near-identical optoelectronic properties but provide a tool to create a better-optimized film morphology when blended with a non-fullerene acceptor. This strategy allows improving the device performance to over 18 %, higher than that obtained with the corresponding D1 -A or D2 -A bipolymers (around 17 %). Hence, side-chain hybridization is a promising strategy to design efficient D1 -A-D2 -A terpolymer donors that are insensitive to the D1 /D2 monomer ratio, which is beneficial for the scaled-up synthesis of high-performance materials.

SYNTHESIS AND PHOTOCHEMICAL PROPERTIES OF NEW STYRYLQUINOLINE-CONTAINING POLYMERS

Compounds 1a, 1b and 5c, 5d were obtained by Knoevenagel condensation with the corresponding aromatic aldehydes during 14 hours. The new methacrylic monomers with styrylquinoline containing moiety were synthesized by reaction the alcohols with methacryloyl chloride. Polymers were synthesized by free radical polymerization. Polymerization ability was investigated and kinetic parameters were determined for compounds 2a, 2b and 6c, 6d during thermoinitiated homopolyme­rization. Polymerization was carried out for 10% solutions of monomers in DMF at 80 °C in argon atmosphere with 1% AIBN. Polymers were characterized by 1HNMR spectroscopy. The speed of polymerization of all new mono­mers was higher than for MMA and phenyl methacrylate due to the effect of the substi­tuent in the p-position of the aromatic ring of the styrylquinoline fragment. In addition, the speed of polymerization increased due to the donor effect of the substituent. It was established that the speed of polymerization for 2b is higher than for monomer 2a. It is possible that decrease in the speed of polymerization occurs due to the substituent, which exhibits electron-accepting properties and can be a trap for free radicals. The results of photochemical and optical activities of the corresponding po­lymers are presented. Investigations of the absorption spectra of the synthesized polymers prove that the optically active styrylquinoline fragment in the polymers is preserved. Thus the photochemical properties of the new po­lymers will correspond to the properties of styrylquinoline-containing compounds. It was established that the introduction of electron-donating groups in the styrylquinoline fragment leads to a bathochromic shift of the absorption spectrum. Changes in absorption maxima during UV irradiation of compound 3a demonstrate photoinduced trans-cis isomerization. From the obtained and presented results, it can be concluded that polymers with styrylquinoline and iminostyrylquinoline fragments can be considered as promising materials for creating materials based on them that require photosensitivity in a certain range of wavelengths.

Effects of Acyloxy Groups in Anthrabisthiadiazole-Based Semiconducting Polymers on Electronic Properties, Thin-Film Structure, and Solar Cell Performance

Abstract Donor-acceptor (D-A) polymers with the anthra[1,2-c:5,6-c′]bis([1,2,5]thiadiazole) (ATz)-based acceptor unit bearing acyloxy groups in the 6,12-positions were synthesized. By incorporating electron-withdrawing acyloxy groups, the synthesized monomers 5a and 5b showed a down-shifted HOMO while maintaining LUMO energy level compared to the alkoxy-substituted ATz monomer ATz2T-o6OD, which we have previously reported. The DFT calculations revealed that the LUMO of the ATz core at 6,12-positions is a nodal plane with negligible changes in LUMO energy levels. In contrast, despite the presence of the acyloxy groups, the polymer PATz4T-a12R (a12R = a12OD and a12DT) synthesized in this study was found to have higher HOMO energy levels than the previously reported alkoxy-substituted polymer PATz4T-o6OD. Such elevation of the HOMO energy levels may be attributed to the unique electronic effects of the acyloxy groups, where the electronic effects of the functional groups are weakened by the lengthening of the π-electron system in the polymer and the electron-donating mesomeric effects may be dominant. PATz4T-a12R formed unsuitable edge-on orientation and large phase separation in the blended films, resulting in solar cells using it exhibiting a lower power conversion efficiency (PCE) of 3.47% than that using PATz4T-o6OD.

Phosphodiester Silybin Dimers Powerful Radical Scavengers: A Antiproliferative Activity on Different Cancer Cell Lines.

Silibinin is the main biologically active component of silymarin extract and consists of a mixture 1:1 of two diastereoisomeric flavonolignans, namely silybin A (1a) and silybin B (1b), which we call here silybins. Despite the high interest in the activity of this flavonolignan, there are still few studies that give due attention to the role of its stereochemistry and, there is still today a strong need to investigate in this area. In this regard, here we report a study concerning the radical scavenger ability and the antiproliferative activity on different cell lines, both of silybins and phosphodiester-linked silybin dimers. An efficient synthetic strategy to obtain silybin dimers in an optical pure form (6aa, 6ab and 6bb) starting from a suitable building block of silybin A and silybin B, obtained by us from natural extract silibinin, was proposed. New dimers show strong antioxidant properties, determined through hydroxyl radical (HO●) scavenging ability, comparable to the value reported for known potent antioxidants such as quercetin. A preliminary screening was performed by treating cells with 10 and 50 μM concentrations for 48 h to identify the most sensitive cell lines. The results show that silibinin compounds were active on Jurkat, A375, WM266, and HeLa, but at the tested concentrations, they did not interfere with the growth of PANC, MCF-7, HDF or U87. In particular, both monomers (1a and 1b) and dimers (6aa, 6ab and 6bb) present selective anti-proliferative activity towards leukemia cells in the mid-micromolar range and are poorly active on normal cells. They exhibit different mechanisms of action in fact all the cells treated with the 1a and 1b go completely into apoptosis, whereas only part of the cells treated with 6aa and 6ab were found to be in apoptosis.

Organic Host Encapsulation Effects on Nitrosobenzene Monomer-Dimer Distribution and C-NO Bond Rotation in an Aqueous Solution.

The intermolecular (monomer-dimer equilibrium) and intramolecular (C-NO and C-NMe2 rotations) dynamics of 4-nitrosocumene (1a) and 4-(N,N-dimethylamino)nitrosobenzene (1b), respectively, were found to be controlled by the medium (water) and the host environment (organic capsules and cavitands). The ability of water to shift the equilibrium toward the dimer appears to result from dipolar stabilization of the polar dimer structure and has a resemblance to water's known ability to favor organic cycloaddition reactions. In an aqueous medium, a range of organic hosts selectively include only the nitrosocumene monomer 1a. Encapsulation in the octa acid duplex (OA2) selects two 1a monomers rather than a dimer structure. Octa acid encapsulation also results in more restricted intramolecular C-N rotations of the guest 1b.

Hyperbranched Poly(ester-enamine) from Spontaneous Amino-yne Click Reaction for Stabilization of Gold Nanoparticle Catalysts.

Hyperbranched polymers have garnered much attention due to attractive properties and wide applications, such as drug-controlled release, stimuli-responsive nano-objects, photosensitive materials and catalysts. Herein, two types of novel hyperbranched poly(ester-enamine) (hb-PEEa) were designed and synthesized via the spontaneous amino-yne click reaction of A2 monomer (1, 3-bis(4-piperidyl)-propane (A2a ) or piperazine (A2b )) and B3 monomer (trimethylolpropanetripropiolate). According to Flory's hypothesis, gelation is an intrinsic problem in an ideal A2 +B3 polymerization system. By controlling the polymerization conditions, such as monomer concentration, molar ratio and rate of addition, a non-ideal A2 +B3 polymerization system can be established to avoid gelation and to synthesize soluble hb-PEEa. Due to abundant unreacted alkynyl groups in periphery, the hb-PEEa can be further functionalized by different amino compounds or their derivates. The as-prepared amphiphilic PEG-hb-PEEa copolymer can readily self-assemble into micelles in water, which can be used as surfactant to stabilize Au nanoparticles (AuNPs) during reduction of NaBH4 in aqueous solution. As a demonstration, the as-prepared PEG-hb-PEEa-supported AuNPs demonstrate good dispersion in water, solvent stability and remarkable catalytic activity for reduction of nitrobenzene compounds.

Kinetic theory of A2+B3+B2 type hyperbranched polymerization

The kinetics of the hyperbranched polymerization with A2, B3 and B2 monomer has been developed in this work. The analytical expressions of the size distribution function and the various molecular parameters of the resulting hyperbranched polymers were derived. Compared with A2+B3 type hyperbranched polymerization, with the addition of B2 type monomer in the reaction system, the gel range moves in smaller value and a narrower interval of the initial functional ratio (α), i.e. initial ratio of B to A group in respective B3 and A2 monomer. At a specified feed ratio α, the addition of B2 monomer can enhance the critical conversion of A groups and reduce that of B groups as well. The addition of linear B2 monomer in reaction system can significantly reduce the degree of branching and improve the number-average degree of polymerization for the products obtained. In this way, according to the theoretical research in this work, molecular structure and parameters can be effectively designed by choosing the appropriate feed ratio of monomers for the hyperbranched polymerization of A2+B3+B2 type.

A mechano-reactive coarse-grained model of the blood-clotting agent von Willebrand factor.

The von Willebrand Factor (vWF) is a large blood glycoprotein that aids in hemostasis. Within each vWF monomer, the A2 domain hosts a cleavage site for enzyme ADAMTS13, which regulates the size of vWF multimers. This cleavage site can only be exposed when an A2 domain unfolds, and the unfolding reaction energy landscape is highly sensitive to the force conditions on the domain. Based on previous optical tweezer experimental results, we advance here a new activated A2 monomer model (AA2MM) for coarse-grained modeling of vWF that accurately represents the force-based probabilistic change between the unfolded/refolded states. A system of springs is employed to mimic the complex mechanical response of vWF monomers subject to pulling forces. AA2MM was validated by comparing monomer scale simulation results to data from prior pulling experiments on vWF monomer fragments. The model was further validated by comparing multimer scale Brownian dynamics simulation results to experiments using microfluidic chamber microscopy to visualize tethered vWF proteins subject to flow. The A2 domain unfolding reaction was studied in bulk flow simulations (pure shear and elongation flow), giving evidence that elongational flow drives the vWF size regulation process in blood. The mechanoreactive, coarse-grained AA2MM accurately describes the complex mechanical coupling between human blood flow conditions and vWF protein reactivity.

Structural, spectroscopic and theoretical studies of 8-hydroxyquinolinium bromide and its monohydrate

Molecular structures and properties of 8-hydroxyquinolinium bromide (1) and its monohydrate (2) have been characterized by X-ray diffraction, B3LYP/6-311++G(d,p) calculations and FTIR spectroscopy. In the anhydrate 1 the ions of 8-hydroxyquinolinium cation and bromide anion are hydrogen-bonded into centrosymmetric dimers through the N···Br and O(8)···Br bonds of the distances of 3.220(3) and 3.157(2) Å, respectively. In monohydrate 2 the water molecule mediates in hydrogen bonds OH···O and OH···Br between the bromide and 8-hydroxyquinolinium ions. The types of intermolecular hydrogen bonds in 8-hydroxyquinolinium cation is connected to the conformational preference of the hydroxyl group. The theoretically optimized models of 8-hydroxyquinolinium bromide anhydrous dimer 1b and dimer hemihydrate 2b better reproduce all interionic hydrogen bonds than these models of monomers 1a and 2a, consistent with the experimental and theoretical infrared spectra. The potential energy distribution (PED) have been used to assign the vibrational spectra.

Friedel–Crafts A2 + B4 Polycondensation toward Regioselective Linear Polymer with Rigid Triphenylmethane Backbone and Its Property as Gas Separation Membrane

This report presents an unexpected acid-catalyzed Friedel–Crafts (F–C) hydroxyalkylation polymerization to produce linear polymers containing triphenylmethane repeating units in the backbone. The polymerization of 4-nitrobenzaldehye (NBA, a difunctional A2 monomer) and 1,4-dimethoxybenzene (DMB, a B4 monomer with four identical reactive sites) demonstrated very high regioselective reactions at the 2,5 positions of DMB monomer, leaving 3,6 positions unreacted to avoid any branched structure. The produced linear polymers were always terminated with DMB units at both ends, allowing easy synthesis of high-molecular-weight polymers by using excess amount of NBA. The polymerizations used various inexpensive 4-substituted benzaldehydes and para-disubstituted benzenes as the A2 and B4 monomers, producing a series of linear polymers with tunable side group compositions. These polymers with high molecular weight and rigid triphenylmethane backbone structure were cast into freestanding membranes and demonstrated exc...

Structural Manipulation of the Conjugated Phenyl Moiety in 3-Phenylbenzofulvene Monomers: Effects on Spontaneous Polymerization.

Spontaneous polymerization is an intriguing phenomenon in which pure monomers begin their polymerization without initiators or catalysts. Previously, 3-phenylbenzofulvene monomers were found to polymerize spontaneously after solvent removal. Here, eight new 3-substituted benzofulvene monomers 1a–h were synthesized in order to investigate the effects of differently substituted aromatic rings in position 3 of the benzofulvene scaffold on spontaneous polymerization. The newly synthesized monomers maintained the tendency toward spontaneous polymerization. However, monomer 1a, bearing an ortho-methoxy substituted phenyl, polymerized hardly, thus producing low polymerization yields, inhomogeneous structure, and low molecular weight of the obtained polymeric material. This result suggested the importance of the presence of hydrogen atoms in the 2′-position to achieve productive interactions among the monomers in the recognition step preluding the spontaneous polymerization and among the monomeric units in the polybenzofulvene backbones. Moreover, this study paves the way to modify the pendant rings in position 3 of the indene scaffold to synthesize new polybenzofulvene derivatives variously decorated.

New Polymer Syntheses Part 60: A Facile Synthetic Route to Polyamides Based on Thieno[2,3-b]thiophene and Their Corrosion Inhibition Behavior

Polyamides containing thieno[2,3-b]thiophene moiety were prepared via a simple polycondensation reaction of the diaminothieno[2,3-b]thiophene monomer 1a with different kinds of diacid chlorides (including oxalyl, adipoyl, sebacoyl, isophthaloyl, terephthaloyl, 4,4′-azodibenzoyl, 3,3′-azodibenzoyl, p-phenylene diacryloyl) in the presence of LiCl and NMP as a solvent through lowtemperature solution polycondensation. The chemical structures of model compound and synthesized polyamides were confirmed by FTIR, nuclear magnetic resonance spectroscopy (including 1H-NMR and 13C-NMR) and elemental analysis. In addition, the thermal stability, crystallinity structure and surface morphology of synthesized polyamides were characterized via thermogravametric analysis (TGA), wide-angle X-ray diffraction analysis (WAXD) and scanning electron microscopy (SEM). Also, the corrosion inhibition behavior of selected examples of polyamides was investigated; the inhibitive effect of the investigated polymers for carbon steel in 1.0 mol·L−1 HCl was studied using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) methods. PDP results displayed that the polyamides containing thieno[2,3-b]thiophene moiety can be as mixed-type inhibitors. The inhibition efficiency (P, %) was found to be in the range from 67.13% to 96.01%. There is an increase in P by the synthesized polymers in comparison to the starting monomer. The adsorption of these polymers was found to obey Langmuir adsorption isotherm.

Urea dimethacrylates functionalized with bisphosphonate/bisphosphonic acid for improved dental materials

ABSTRACTIncorporation of bisphosphonate/bisphosphonic acid groups in dental monomer structures should increase interaction of these monomers with dental tissue as these groups have strong affinity for hydroxyapatite. Therefore, new urea dimethacrylates functionalized with bisphosphonate (1a, 1b) and bisphosphonic acid (2a, 2b) groups are synthesized and evaluated for dental applications. Monomers 1a and 1b are synthesized from 2‐isocyanatoethyl methacrylate (IEM) and two bisphosphonated amines (BPA1 and BPA2), prepared as reported elsewhere. Selective dealkylation of the bisphosphonate ester groups of 1a and 1b using trimethylsilyl bromide (TMSBr) gives monomers (2a and 2b) with bisphosphonic acid functionality. X‐ray diffractometer (XRD), Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS) analyses of monomer‐treated HAP particles show that 2a induces formation of stable monomer‐calcium salts, similar to 10‐methacryloyloxydecyl dihydrogen phosphate (MDP), with higher chemical interaction than 2b. The photopolymerization studies indicate good copolymerizability with commercial dental monomers. In vitro studies on NIH 3T3 mouse embryonic fibroblast cells have clearly shown that the tested monomers (1b and 2b) are not toxic according to the MTT standards. All these properties make these monomers suitable as biocompatible cross‐linkers/adhesives for dental applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3195–3204

Soluble, Allyl-Functionalized Deoxybenzoin Polymers

We describe the synthesis of allyl-substituted deoxybenzoin-based aromatic polyesters that combine the advantageous thermal properties of deoxybenzoin with the processability and reactivity of pendent unsaturated groups. A thermally induced Claisen rearrangement of bis-allyl ether-substituted deoxybenzoin 2 produced 3,3′-bis-allyl-4,4′-bishydroxydeoxybenzoin (BA-BHDB, compound 1) as a novel A2 monomer. BA-BHDB 1 polymerized readily with isophthaloyl chloride to produce a novel set of functional aromatic polyesters. These allyl-substituted polymers exhibited marked solubility advantages over deoxybenzoin-based polymers lacking such pendent groups, affording homogeneous solutions in numerous organic solvents. The processability contributed by the allyl groups afforded access to relatively high molecular weight aromatic polyesters, with estimated number-average molecular weight (Mn) values exceeding 20 kDa. Interestingly, evaluation of the thermal properties of these polymers revealed that the pendent allyl ...

PhP=CPh2 and Related Phosphaalkenes: A Solution Equilibrium between a Phosphaalkene and a 1,2‐Diphosphetane

The synthesis of phosphaalkenes, ArP=C(R)Ph (1, a: Ar = Ph, R = Ph; b: Ar = o‐Tol, R = Ph; c: Ar = Mes, R = H), bearing sterically less hindered substituents is reported. Phosphaalkenes 1a–b were prepared by treating Ph2C=O with ArP(Li)SiMe3, whereas 1c was accessed from the AlCl3‐mediated reaction of ArP(SiMe3)2 and PhC(O)H. Both 1a and 1b dimerize to afford their respective 1,2‐diphosphetanes (2a and 2b). Compound 2a was characterized by X‐ray crystallography. Dissolution of pure 2a in THF resulted in a temperature dependent equilibrium with monomer 1a (ΔHo = –94.6 ± 14.6 kJ mol–1; ΔSo = –284 ± 48 J mol–1 K–1). Although monomer E/Z‐1c was identified in solution by its characteristic downfield 31P NMR chemical shift (δ = 247.1, 231.5), it was accompanied by the formation of what we believe are oligomers (δ = –25 to 10 ppm, br.). Attempts to trap phosphaalkenes 1a and 1b by treatment with W(CO)5(MeCN) afforded mixtures of complexes W(CO)5(1a–b) (4a–b) and W(CO)4(1a–b)2 (5a–b), the disubstituted species being subjected to X‐ray crystallographic characterization (5a).

Preparation and characterization of hyperbranched poly(ether sulfone) and its application as a coating additive for linear poly(ether sulfone)

ABSTRACTHyperbranched poly(ether sulfone) (HPES), a suitable coating additive for improving the rheological properties of linear poly(ether sulfone) (LPES), was easily produced via polymerization of commercially available bisphenol S (A2 monomer, BPS) and synthesized 2,4′,6‐trifluoro‐phenylsulfone (BB′2 monomer, TF). During this reaction, fluoro‐ or phenolic‐terminated HPES (F‐HPES or OH‐HPES) could be facilely obtained by controlling the feed mole ratios of the two monomers. The polymerization mode A2 + BB′2 was confirmed by analyzing the model compounds and the degree of branching (DB) was calculated systematically. In addition, the synthesized polymers' chemical structures were exhibited by FTIR, 1H NMR as well as 19F NMR spectroscopy. Notably, the addition of 1 wt % HPES reduced the melt viscosity and improved the high temperature liquidity of LPES because of its unique spherical shape. Furthermore, the addition of HPES did not have a negative impact on the performance of LPES, which was attributed to the good miscibility between HPES and LPES. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43892.

Metathesis polymerization of diphenylacetylenes possessing electron-donating and electron-withdrawing groups and emission properties of polymers

Diphenylacetylenes containing electron-donating groups (O-n-C8H17: 1A, OCH3: 1B, SCH3: 1C) and electron-withdrawing groups (COOCH3: 1a, COCH3: 1b, CF3: 1c, CN: 1d) were polymerized using TaCl5/n-Bu4Sn. The polymerization of diphenylacetylenes possessing both an n-octyloxy group and an electron-withdrawing group (1Aa, 1Ab, 1Ac) was also examined in the same conditions. Electron-donating group-containing monomers (1A–C) polymerized to afford relatively high-molecular-weight polymers (Mn=240,000–622,000). Ester-containing monomers (1a and 1Aa) also polymerized to give polymers with high molecular weights, while the polymerization of acetyl- and trifluoromethyl-containing monomers (1b, 1c, 1Ab, 1Ac) gave low-molecular-weight polymers. Cyano-containing monomer (1d) did not polymerize because cyano groups deactivated tantalum catalysts. Polymers having electron-donating groups (2A–C) emitted green-colored lights, and the emission maxima were around 505nm. Ester-containing polymers 2a and 2Aa showed yellow-colored emissions, and the emission maxima were 520nm. These polymers showed emission red-shifts between the solution and cast film.