Reaction Of Poly Research Articles

Synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by poly(ferric 2-acrylamido-2-methylpropanesulfonate)

Poly(ferric 2-acrylamido-2-methylpropanesulfonate) (PFAMPS) was prepared via the reaction of poly(2-acrylamido-2-methylpropanesulfonic acid) and Fe(OH)3. PFAMPS was used as a heterogeneous catalyst for the Biginelli reaction of aldehyde, ethyl acetoacetate, and urea to synthesize 3,4-dihydropyrimidin-2(1H)-ones with yields of 70–87%. PFAMPS can be recycled six times without significant loss in catalytic activity. For comparison, ferric lignosulfonate (FLSA), ferric cellulose sulfonate (FCSA), ferric starch sulfonate (FSSA), and ferric 732 cation exchange resin (FACER) were used as catalysts of the Biginelli reaction. It was shown that the catalytic activities of recycled FLSA, FCSA, FSSA, and FACER significantly decreased after two reactions. Fe3+ in the polymer sulfonates acted as the catalyst for the Biginelli reaction. PFAMPS was the chelate, where the action between Fe3+ and the poly(2-acrylamido-2-methylpropanesulfonate) matrix was strong, and Fe3+ lost little from the PFAMPS. However, significant Fe3+ loss was observed in the FLSA, FCSA, FSSA and FACER polymer matrices after reuse.

Highly Adhesive and Sustainable UV/Heat Dual-Curable Adhesives Embedded with Reactive Core-Shell Polymer Nanoparticles for Super-Narrow Bezel Display.

To achieve the seamless characteristics of displays, liquid crystal (LC) devices need a super-narrow bezel design. This device architecture can be constructed using functional adhesives that possess excellent physical and chemical properties. In this study, mechanically robust ultraviolet (UV)/heat dual-curable adhesives with outstanding reliability and processability have been fabricated using reactive poly(methyl methacrylate) (PMMA)/polyethyleneimine (PEI) core-shell nanoparticles. Their curing characteristics, narrow drawing processability, adhesive strength, elongation at break, and the contact contamination of LCs have been investigated. Compared to conventional adhesive material, the proposed adhesive containing multifunctional PMMA/PEI nanoparticles afforded a high adhesion strength of 40.2 kgf cm−2 and a high elongation of 64.8% due to the formation of a firm crosslinked network with matrix resins comprising bisphenol A epoxy resin and bisphenol A glycerolate dimethacrylate. Moreover, the proposed adhesive showed an excellent narrow drawing width of 1.2 mm, which is a prerequisite for super-narrow bezel display. With regard to LC contamination, it was found that the level of contamination could be remarkably reduced to 61 µm by a high-temperature curing process. This study makes a significant contribution to the development of advanced display, because it provides robust and sustainable display adhesives based on nanomaterials, thereby enhancing the life and sustained operability of displays.

Ultrasound-accelerated covalent-functionalization of reduced graphene oxide with imidazolium-based poly(ionic liquid)s by Diels-Alder click reaction for supercapacitors

Herein, we developed an efficient method for covalent functionalization of reduced graphene oxide (rGO) with imidazolium-based poly(ionic liquid)s via the Diels-Alder (DA) click reaction in deep eutectic solvents (DESs). Firstly, poly(ionic liquid)s (P(F-IL)s) containing furfuryl and imidazolium were prepared by the reaction of poly(chloromethylstyrene-co-maleicanhydride), furfuryl amine and methylimidazole. Afterward, the P(F-IL)s were grafted directly on the rGO surface via the DA reaction in a deep eutectic solvent (DES) without catalyst under ultrasonication. The obtained hybrid materials were characterized by FT-IR, TGA, Raman spectroscopy, XPS, SEM, and TEM. The capacitive and electrochemical behaviors of the hybrid materials were studied by using cyclic voltammetry (CV) and electro chemical impedance spectroscopy (EIS). In CV, the rGO-P(F-IL) hybrid showed the largest capacitance and EIS revealed a lower diffusion resistance compared to that of rGO, which indicated a good electrochemical capacitor behavior of the hybrid.

Reactive Polymer Targeting dsRNA as Universal Virus Detection Platform with Enhanced Sensitivity.

Reactive poly(pentafluorophenyl acrylate) (PPFPA)-grafted surfaces offer a versatile platform to immobilize biomolecules. Here, we utilize PPFPA-grafted surface and double-stranded RNA (dsRNA) recognizing J2 antibody to construct a universal virus detection platform with enhanced sensitivity. PPFPA on silicon substrates is prepared, and surface hydrophilicity is modulated by partial substitution of the pentafluorophenyl units with poly(ethylene glycol). Following dsRNA antibody immobilization, the prepared surfaces can distinguish long dsRNAs from single-stranded RNAs of the same length and short dsRNAs. As long dsRNAs are common byproducts of viral transcription/replication, these surfaces can detect the presence of different kinds of viruses without prior knowledge of their genomic sequences. To increase dsRNA detection sensitivity, a two-step method is devised where the captured dsRNAs are visualized with multiple fluorophore-tagged J2 antibodies. We show that the developed platform can differentiate foreign long dsRNAs from cellular dsRNAs and other biomolecules present in the cell lysate. Moreover, when tested against cells infected with hepatitis A or C viruses, both viruses are successfully detected using a single platform. Our study shows that the developed PPFPA platform immobilized with J2 antibody can serve as a primary diagnostic tool to determine the infection status for a wide range of viruses.

The effect of in situ‐formed copolymers on the morphology of reactive poly(phenylene ether)/poly(amide‐6) blends

AbstractPoly(phenylene ether) (PPE)/poly(amide‐6) (PA6) blends are examined in light of the information provided by two‐dimensional chromatography and chemorheology. Chromatography provides a snapshot of the blend composition in the finished material, while rheology presents us with a direct insight into the reactions taking place in the melt. Block copolymer formation is chromatographically confirmed for the blends prepared with a coupling agent, but also for the blend prepared without any coupling agent. No co‐continuous morphology is observed by scanning electron microscope. Instead, a coarse structure of PPE droplets in the PA6 matrix is obtained for the blend prepared without coupling agent. This is explained by the combined effects of the low viscosity of PA6 and the inherently formed copolymers. The PPE domains are smaller in the blends prepared with the coupling agents. Their size is correlated with the copolymer formation, surface tension, and interphase relaxation time. The data evidence a complex system where reactions resulting in the formation of copolymer via coupling or grafting take place together with the extension of the PPE and condensation growth of the PA6 polymers.

Detection of stress in polymers: mechanochemical activation of CuAAC click reactions in poly(urethane) networks.

We report on copper(i)-bis(N-heterocyclic carbene)s (NHC) for quantitative stress-sensing, embedded within polyurethane networks, triggering a fluorogenic copper(i) azide alkyne cycloaddition (CuAAC) of 8-azido-2-naphtol and 3-hydroxy phenylacetylene. A completely transparent, force responsive poly(urethane) material is generated, allowing a quantification of the applied stress.

Synthesis of CO2-based polycarbonate-g-polystyrene copolymers via NMRP.

The construction of a graft copolymer is an effective method to modify the properties of CO2-based aliphatic polycarbonate (CO2-APC) for meeting specific needs. Herein, we describe a facile route for the synthesis of CO2-based APC-graft-polystyrene copolymers using a "grafting from" strategy. Firstly, the copolymerization of CO2 and epichlorohydrin (ECH) was performed for the synthesis of the APC of poly(CO2/ECH). Then, a functionalized-APC can be prepared by the substitution reaction of poly(CO2/ECH) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) that can serve as a precursor for the graft compolymer of P(CO2/ECH)-g-polystyrene via nitroxide-mediated radical polymerization (NMRP). The intermediates at each step and final graft copolymers were characterized using 1H NMR, GPC, DSC and TG analyses.

Temperature and pH Responsive Janus Silica Nanoplates Prepared by the Sol-Gel Process and Postmodification.

During the process of emulsifying and hydrolyzing, reactive poly(3-(triethoxysilyl)propyl methacrylate)-b-polystyrene (PTEPM-b-PS) diblock copolymers can self-assemble and become cross-linked to form hollow spheres in situ with polystyrene on their inner surfaces. The addition of tetraethoxysilane (TEOS), which was hydrolyzed and condensed together with PTEPM block, can make those spheres as soft foldable capsules or hard hollow spheres depending on the amount of added TESO. Then postmodification, the surface-initiated Atom Transfer Radical Polymerization (ATRP) was applied to afford stimuli-responsive spheres, and the corresponding responsive Janus nanoplates (RJPs) were finally obtained by crushing those responsive hollow spheres (HSs) showing smart tunable emulsifiability and great potential in oily water purification. This facile method to fabricate HSs and RJPs could be used for preparing different Janus polymer-inorganic capsules and nanoplates with varied functions by changing the chemical composition of copolymer surfactants as well as the postmodification process.

Multiple Hydrogen-Bonding Assisted Scratch–Healing of Transparent Coatings

The partial cross-linking reaction of poly(vinyl alcohol) (PVA) by esterification using poly(acrylic acid) (PAA) as a cross-linking agent was performed to obtain a PVA–PAA supramolecular polymer complex. The PVA–PAA coatings with a different molar ratio between hydroxyl and carboxyl groups were prepared to examine scratch–healing ability. These coatings exhibited high optical transparency and excellent scratch–healing properties, which are attributed to considerable amount of free hydroxyl groups at the scratched interfaces to reversibly form multiple hydrogen bonds. Importantly, the PVA–PAA polymer was capable of initiating scratch recovery at temperature of 20 °C and relative humidity (RH) of 40%. Scratches produced on the PVA–PAA polymer coatings with different constant loading in the range of 1.5–2.7 N were healed significantly more rapidly under humid conditions (RH = 99%). Increase of cross-linking temperature also resulted in similar effect but with some reduction of the final scratch healing ratio.

Devulcanization of Waste Rubber and Generation of Active Sites for Silica Reinforcement.

Each year, hundreds of millions of tires are produced and ultimately disposed into nature. To address this serious environmental issue, devulcanization could be one of the sustainable solutions that still remains as one of the biggest challenges across the globe. In this work, sulfur-vulcanized natural rubber (NR) is mechanochemically devulcanized utilizing a silane-based tetrasulfide as a devulcanizing agent, and subsequently, silica (SiO2)-based rubber composites are prepared. This method not only breaks the sulfur–sulfur cross-links but also produces reactive poly(isoprene) chains to interact with silica. The silica natural rubber composites are prepared by replacing 30% fresh NR by devulcanized NR with varying contents of silica. The composites exhibit excellent mechanical properties, tear strength, abrasion resistance, and dynamic mechanical properties as compared with the fresh natural rubber silica composites. The tensile strength of devulcanized rubber-based silica composites is ∼20 MPa, and the maximum elongation strain is ∼921%. The devulcanized composites are studied in detail by chemical, mechanical, and morphological analyses. Thus, the value added by the devulcanized rubber could attract the attention of recycling community for its sustainable applications.

Amphiphilic reactive poly(glycidyl methacrylate)-block-poly(dimethyl siloxane)-block-poly(glycidyl methacrylate) triblock copolymer for the controlling nanodomain morphology of epoxy thermosets

The amphiphilic reactive tricopolymer Poly(glycidylmethacrylate) -b-Poly(dimethylsiloxane)-b-Poly(glycidylmethacrylate) (PGMA-b-PDMS-b-PGMA) was synthesized via atom transfer radical polymerization (ATRP) from the PDMS macro-initiator and glycidylmethacrylate (GMA). The internal structure of the reactive tricopolymer was described by Fourier transform infrared spectroscopy (FITR), nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). The PGMA-b-PDMS-b-PGMA consisted of reactive epoxy-miscible PGMA blocks, which can been involved in the cross-linking network by covalent bonds, and an epoxy-immiscible PDMS block, which separated to give the nanostructures. The morphology of the nanostructure thermosetting blends before and after curing was not much different and as well as the difference in miscibility between its subchains, inferring the formation followed the self-assembly mechanism. Static contact angle measurement and differential scanning calorimetry (DSC) indicated that the hydrophobic and the glass transition temperature were significantly increased by introducing the reactive triblock copolymer.

On-Demand Oil-Water Separation by Environmentally Responsive Cotton Fabrics.

Environmentally responsive cotton fabrics were fabricated by dip-coating ABC miktoarm star terpolymers, which contain reactive poly(3-triisopropyloxysilylpropyl methacrylate) blocks, hydrophobic poly(dimethylsiloxane) (PDMS) blocks, and hydrophilic poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) blocks. The functionalized cotton fabrics with perfectly alternating PDMS and PDMAEMA blocks show underoil superhydrophobicity and underwater superoleophobicity. The wettability and permeability of the functionalized fabrics can be readily adjusted by the contacting medium. More interestingly, surface reconstruction causes a reduction in the breakthrough pressure of the nonwetting phase. The adaptive permeability endows the functionalized cotton fabrics with the capability to separate heavy oil–water–light oil ternary mixtures.

Permanganate-Induced Efficient Mineralization of Poly(vinylidene fluoride) and Vinylidene-Fluoride Based Copolymers in Low-Temperature Subcritical Water

Reactions of poly(vinylidene fluoride) [PVDF], poly(vinylidene fluoride-co-hexafluoropropylene) [poly(VDF-co-HFP)] copolymer, and poly(vinylidene fluoride-co-perfluoromethyl vinyl ether) [poly(VDF-co-PMVE)] copolymer in subcritical water were performed with the aim to develop a technique for recycling fluorine element. By addition of KMnO₄ to the system, quasi-complete mineralization of PVDF was achieved at a rather low temperature (250 °C). When PVDF was reacted for 18 h in the presence of KMnO₄ (158 mM, corresponding to a 1.6-fold molar excess relative to both fluorine and carbon atom contents of PVDF), the fluoride ions (F–) yield reached 100%, and the amount of remaining total organic carbon decreased to 2% of the carbon atoms in the initial PVDF. Poly(VDF-co-HFP) and poly(VDF-co-HFP) copolymers also showed quasi-complete mineralizations under the same conditions. During the reactions, MnO₄– was modified into MnO₂. Compared to the previous method using H₂O₂, the reaction temperature that allows a complete mineralization was reduced by 50 °C.

Reactive Conjugated Polymers for the Modulation of Islet Amyloid Polypeptide Assembly.

Misfolding and abnormal assembly of proteins cause many intractable diseases. The modulation of the assembly process of these proteins could contribute to understanding and controlling amyloid protein aggregation. Previous works focused mainly on the inhibition of the assembly process. To broaden the interaction modality of modulators with proteins for developing new modulators, in this work, we designed and synthesized two reactive poly ( p-phenylene vinylene) polymers, respectively, functionalized with N-hydroxysuccinimide ester (PPV-NHS) and pentafluorophenol ester (PPV-PFP), which exhibited the prevention or co-assembly effect on the aggregation process of islet amyloid polypeptide (IAPP). Cell assays demonstrated that both of the two polymers could effectively eliminate the cytotoxicity of IAPP. Moreover, PPV-NHS also could irreversibly disrupt preformed IAPP fibrils. We envision that PPV-NHS and PPV-PFP might offer a new design method for the modulation of protein assembly.

Stimuli-responsive poly(hydroxyethyl methacrylate) hydrogels from carboxylic acid-functionalized crosslinkers.

Tailoring hydrogel properties by modifications of the crosslinker structure is a good method for the design of hydrogels with a wide range of properties. In this study, two novel carboxylic acid-functionalized dimethacrylate crosslinkers (1a and 2a) are synthesized by the reaction of poly(ethylene glycol) or 2-hydroxyethyl disulfide with tert-butyl α-bromomethacrylate followed by cleavage of tert-butyl groups using trifluoroacetic acid. Their copolymerization reactivity with 2-hydroxyethyl methacrylate (HEMA) investigated by photopolymerization studies performed on photo-differential scanning calorimetry shows higher reactivity of 2a compared to 1a. These crosslinkers are then used at different ratios for fabrication of pH- and redox-responsive poly(2-hydroxyethyl methacrylate)-based hydrogels. The swelling behavior of the hydrogels is found to be dependent on the structure of the crosslinker, degree of crosslinking, pH, and CaCl2 concentration. The redox-responsive behavior is demonstrated by degradation of the hydrogel upon exposure to 1,4-dithiothreitol. The dye Rhodamine 6G and the drug resorcinol are used as models to demonstrate the pH and redox dependent release of loaded compounds from the hydrogels. The electrostatic interactions between the carboxylate groups and the positively charged R6G are found to govern the release profile in DTT and counteract the diffusion of dye molecules and significant amount of release (79% in 120 hr) occurs only at highly acidic conditions. The degradation mediated release in DTT is observed better in case of resorcinol (around 88% in 5 hr). Overall, these hydrogels can be regarded as good candidates for several applications, such as matrices for controlled release, tissue repair, and regeneration.

Synthesis and characterization of polycaprolactone-based segmentedpolyurethanes

Segmented polyurethanes were synthesized by the reactions of poly($\varepsilon $-caprolactone) (PCL)-diol and 1,6-hexamethylene diisocyanate through bulk polymerization without using solvent, initiator, or catalyst. Phase separation and hydrogen bond formation between hard segments or between hard and soft segments were examined by Fourier transform infrared spectroscopy (FTIR)-ATR and X-ray diffraction (XRD), while physical and mechanical properties were studied by atomic force microscope, differential scanning calorimeter, dynamic mechanical analysis, and tensile tester. When the diisocyanate content was increased, deconvolution results of FTIR-ATR in C$=$O and N-H regions demonstrated better miscibility of the segments and XRD results showed a significant decrease in the crystallinity of soft segments. Samples having strong hard segment interactions displayed better mechanical properties.

Influence of reactive blending temperature on impact toughness and phase morphologies of PLA ternary blend system containing magnesium ionomer

ABSTRACTIn this study, effects of extrusion temperature on impact toughness and phase morphologies in the reactive poly(lactic acid) (PLA)/epoxy‐containing elastomer (ethylene/n‐butyl acrylate/glycidyl methacrylate [EBA‐GMA]) blend system with magnesium ionomer (magnesium ionomer of ethylene/methacrylic acid copolymer [EMAA‐Mg]), were investigated, and the underlying origin for the dependence of morphology development on reactive blending temperature was analyzed. The extent of reactive compatibilization between PLA/EBA‐GMA and crosslinking of EBA‐GMA initiated by EMAA‐Mg, were determined in terms of Fourier transform infrared spectra of dioxane‐extracted residues, torque rheometer, dynamic mechanical analysis, and gel contents after chloroform extraction. The phase morphologies were studied by electron microscopic observation and dynamic rheological tests. Compared to the ternary blend system containing zinc‐neutralized ionomer of EMAA copolymer (EMAA‐Zn), the ones containing EMAA‐Mg exhibited the less pronounced dependence of notched impact strength on extrusion temperature. With elevating extrusion temperature, the latter ternary blends exhibited different “salami‐like” dispersed phase structure. The morphology development with reactive blending temperature was attributed to the remarkable temperature dependence of crosslinking rate of EBA‐GMA phase initiated by the EMAA‐Mg rather than the difference in the extent of compatibilization. The morphology development mechanism with respect to reactive blending temperature was also discussed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47682.

Toward Supertough and Heat-Resistant Stereocomplex-Type Polylactide/Elastomer Blends with Impressive Melt Stability via in Situ Formation of Graft Copolymer during One-Pot Reactive Melt Blending

Stereocomplexation of enantiomeric poly(l-lactide)/poly(d-lactide) (PLLA/PDLA) chains opens up a great opportunity toward sustainable PLA engineering plastic with exceptional heat resistance and durability. However, the processing and applications of stereocomplex-type PLA (SC-PLA) are significantly blocked by its inferior melt stability (i.e., the weak melt memory effect in triggering complete SC crystallization, which makes it hard to obtain exclusive formation of SC crystallites in melt-processed products) and inherent brittleness. In this contribution, we demonstrate an unprecedented strategy to address these obstacles by one-pot reactive melt blending of the equimolar PLLA/PDLA blend with reactive poly(ethylene–methyl acrylate–glycidyl methacrylate) (E-MA-GMA) in the presence of catalyst, where both the stereocomplexation and the grafting of some PLLA/PDLA chains onto E-MA-GMA backbones take place simultaneously and competitively. Intriguingly, the E-MA-graft-PLA copolymer in situ formed can substant...

Preparation, characterization, and properties of novel ultraviolet-curable and flame-retardant polyurethane acrylate

A series of flame-retardant polyurethane acrylate oligomer (FRPUA)–nhexa- phenoxy-cyclotriphosphazene (HPCP) (n = 0, 10, 15, and 20, where n is the amount of HPCP added to a 100 g mixture of FRPUA and other additives) ultraviolet (UV)-cured samples have been prepared. FRPUA was synthesized by the reaction of poly(glycidyl methacrylate) (an unsaturated polyether), a derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) (2DOPO–4,4′- dihydroxy-benzophenone (DHBP)), and isophorone diisocyanate. As a control sample, the polyurethane acrylate (PUA) oligomer and cured PUA sample were also prepared. Surface drying of the PUA and FRPUA–nHPCP curable mixtures required a few seconds under UV irradiation (400 W lamp). The effects of 2DOPO–DHBP and HPCP on the flame retardancy and thermal stability of the PUA system were also investigated. For the FRPUA–nHPCP series, as n increases from 0 to 20, the limiting oxygen index (LOI) increases from 21.1% to 23.3% and the total heat release (THR) slowly decreases from 32.4 to 26.4 kJ/g, while the PUA cured sample possesses the LOI and THR values of 19.0% and 29.2 kJ/g, respectively. Besides, the PUA system can achieve better flame retardant properties when using both 2DOPO-DHBP and HPCP. Thermogravimetric analysis indicates that the amount of char residue of the FRPUA–nHPCP (n = 0, 10, 15, and 20) cured samples ranges from 15.1 to 21.9 wt.%, which are much are higher than 10.5 wt.% for the PUA cured sample. Improving the flame retardancy of the PUA system will expand its applications, such as for paper manufacturing and architectural coatings, while simultaneously retaining the feature of fast surface drying.

Synthesis and characterization of new polymer systems containing indole

Synthesis of some novel indole derivatives has been undertaken by the reaction of poly(maleic anhydride-co-styrene), P(MA-co-St), poly(maleic anhydride-co-chloromethyl styrene), P(MA-co-CMS), poly(maleic anhydride-co-methyl methacrylate), P(MA-co-MMAc) and poly(maleic anhydride-co-methacrylate) P(MA–co–MAc), copolymers with indole in the presence of NaH at -5oC. Compositions of the copolymers were obtained using related 1H NMR spectra and the polydispersity indices of the copolymers determined using gel permeation chromatography (GPC). The anhydride group possesses a higher reactivity with the indole group. The ring opening reaction between the anhydride group and the indole is simple and fast. All the resulted polymers were characterized by FT-IR and 1H NMR spectroscopic techniques. The glass transition temperature (Tg) of all the copolymers was determined by dynamic mechanical thermal analysis (DMTA). All the polymers containing indole groups showed a high glass transition temperature in comparison with the unmodified copolymers (I-IV). It was found that these polymers with indole moieties have high thermal stability and the presence of bulky indole groups in polymer side chains leads to an increase in the rigidity of polymers.