Polyether Amine Research Articles

RETRACTED: Interfacial microstructure and properties between epoxy resin and novel organic hybrid graphene oxide modification ultra high molecular weight polyethylene fiber

Abstract An efficient chemical grafting method was developed to enhance interfacial properties of ultra high molecular weight polyethylene (UHMWPE) fiber reinforced composites. Novel organic hybrid graphene oxide (NOHGO) was successfully prepared via grafting polyetheramine (PEA) on graphene oxide (GO) surface with (3-glycidyloxypropyl) trimethoxysilan (GLYMO) as coupling agent. Even if in the extremely dilute suspension, ideal interfacial modification effect was still easily achieved via efficiently grafting NOHGOs on the surface of UHMWPE fiber. The results revealed NOHGOs were of amino groups and almost unfolding structure. NOHGOs were adhered closely on the surface of UHMWPE fiber, which seems to form a uniform tree-rings-like interfacial structure. This type of interfacial structure benefits to reduce defects of the modified fiber surface, to enhance chemical bonding at weak region (between NOHGO and fiber) in interface, and to make the propagation paths of cracks complication, as to the extremely improvement of interfacial properties. Compared with conventional organic hybrid graphene oxide (OHGO), as many as 14.9% enhancement of the interfacial shear strength (IFSS) and higher energy absorption at the interface region were found via microbond test.

Constructing a simple anti-sandwich structure on carbon fiber surface for simultaneously strengthening and toughening the interphase of epoxy composites

A simple anti-sandwich structure that employs strong, stiff and tough graphene oxide as the core layer, flexible polyether amine as the wrapping connection faces is constructed on carbon fiber surface via chemical grafting approach to strengthen and toughen the interphase of epoxy composites. Impressive 94.4% and 48.7% increments in interfacial toughness and interfacial shear strength are achieved in composites with anti-sandwich structure on fiber, by analogy to those of untreated fiber composites. Pertinent strengthening reasons are mainly enhanced surface energy and the hybrid molecular entanglement. Probable toughening mechanisms include crack deflection by GO core layer, appropriate chemical bonds at interphase, plastic deformation of polyether amine and interfacial friction between adjacent layers due to the build of anti-sandwich structure, as well as the localized toughening effect of the matrix. This work provides a promising thought to obtain advanced composites with excellent strength and toughness.

Comparative studies on thermal and toughness properties of polybenzoxazine composites with two functionalized graphene oxides

Graphene oxide (GO) was functionalized by polyether amine (PEA) via two methods which were one-pot modification in acetone (GON) and two steps with the intermediate product of GOCO-Cl generated (GONS). There were more PEA successfully grafted onto GO for GONS than GON. The onset polymerization temperatures of the benzoxazine (Bz) composites decreased by the inclusion of 1 wt% of GO, GON or GONS. Thermal stability of the polybenzoxazine (PBz) composites was significantly improved indicated from the increase of weight loss temperature. T10, T20 and T50 values of the composites with GONS were higher than that of the others. Toughness of PBzs may be enhanced by the incorporation of nanofillers, and GONS had stronger interfacial interaction with PBz matrix than GON.

A high-strength and healable shape memory supramolecular polymer based on pyrene-naphthalene diimide complexes

Dynamic interaction plays an important role in the design of smart materials, but how to utilize it to realize multifunction without sacrificing performance is also pursued goal. Herein, we report a shape memory network (PTMEG-Py@PEA-NDI) with excellent healability and high-strength by simply blending flexible poly(tetramethylene ether glycol) (PTMEG) and polyether amine (PEA), which contained the complementary recognized groups π-electron-rich pyrene (Py) and π-electron-poor naphthalene diimide (NDI), respectively. The existence of CT interactions between NDI and Py was confirmed by color change, UV–vis spectrum and fluorescence spectrum, and its reversibility can be driven by changing the temperature. Tuning the CT interactions between two precursors by varying the Py content, the mechanical properties of supramolecular polymer can increase from 2.8 MPa to 34.5 MPa. All the samples present excellent shape memory properties with high Rf (98%) and Rr (98%). And the highest self-healing efficiency (95%) was achieved in the sample PTMEG-Py0.25@PEA-NDI which own relative low crosslinking degree.

Improved H2 utilization by Pd doping in cobalt catalysts for reductive amination of polypropylene glycol.

Cobalt based catalysts having enhanced H2 dissociation and desorption were synthesized by inserting a trace amount of palladium. These catalysts were used for the reductive amination of polypropylene glycol (PPG) to polyetheramine (PEA). The catalytic activity toward PEA was significantly increased by incorporating an extremely low content of palladium (around 0.01 wt%) into cobalt based catalysts. The Pd inserted cobalt catalysts promoted reduction of cobalt oxide to cobalt metal and inhibited formation of cobalt nitride in the reductive amination. The Pd inserted cobalt catalysts not only enhanced hydrogen dissociation but also accelerated hydrogen desorption by increasing the electron density of cobalt through interaction between cobalt and palladium. These play a critical role in reducing cobalt oxide or cobalt nitride to cobalt metal as an active site for the reductive amination. Thus, the Pd inserted cobalt catalysts provide improved catalytic performance toward PEA production by maintaining the cobalt metal state.

Designing high thermal conductivity of cross-linked epoxy resin via molecular dynamics simulations.

Coarse-grained (CG) non-equilibrium molecular dynamics simulation was used to study the thermal conductivity of a cross-linked network composed of epoxy resin (E51) and polyether amine (PEA). By probing the mechanism of heat transfer in the cross-linked epoxy resin, we systematically explored the effects of the crosslinking degree, chain length and multi-functional groups of the curing agent on the thermal conductivity behavior. Our results indicate that the thermal conductivity is mainly dependent on the chain length and the functional groups of the curing agent. A shorter chain length and a curing agent with more functional groups contribute to higher thermal conductivity, while the crosslinking degree has a negligible effect. Moreover, it is revealed that the thermal conductivity is manipulated by the non-bonding interaction energy (Epair) and the vibrational density. In general, our work could provide some guidelines for the design and fabrication of a cross-linked epoxy network with high thermal conductivity.

Shrinkage and Strength Properties of Coal Gangue Ceramsite Lightweight Aggregate Concrete

It is a promising and effective method for waste treatment by using coal gangue to make lightweight aggregate concrete. However, lightweight aggregate concrete with low‐density coal gangue ceramsite is prone to cracking during volume shrinkage, which limits its application in the construction industry. In an attempt to resolve the problem of cracking in shrinkage, this study investigated the effect of prewetting time and shrinkage reducing agents on shrinkage volume and concrete strength through a series of concrete shrinkage and strength tests. The experimental results show that shrinkage volume reduced at a prewetting time of 12 hrs or with a 2% addition of D‐230 polyether amine reductant. With the optimal conditions of 12 hrs prewetting time and 2% addition of the reductant, the concrete shrinkage volume significantly decreased with a negligible impact on its strength. Appropriate amount of shrinkage reducing agent and adjustment of prewetting time of coal gangue ceramsite are necessary to reduce the shrinkage rate and improve the stability of the specimen. This is of great significance to wide application of lightweight aggregate concrete with coal gangue ceramsite.

Asymmetric alicyclic amine-polyether amine molecular chain structure for improved energy storage density of high-temperature crosslinked polymer capacitor

Crosslinked structure is proved to be efficient to improve breakdown strength (EB), thermal stability and charge-discharge efficiency (η) of polymer film capacitors, which is of great interest for their application in electric power systems and electrical automobile industry. However, highly crosslinked molecular networks usually lead to weak polarization ability of polymer, which greatly restrict their energy storage density (Ud). To improve polymers’ high-field polarization ability while guaranteeing their EB and thermal stability, we propose the asymmetric molecular chain structure in crosslinked network of epoxy resin by attaching ring-like alicyclic amine (ACA) and linear polyether amine (PEA) on phenol via Mannich reaction. The film exhibits high Ud up to 9.12 Jcm−3 at 550 MVm−1 and ambient temperature with 90% efficiency, which is a record high value for Ud among single-layer polymer under the same condition. At 200 MVm−1 and 120 °C, a future operating condition towards electric-vehicle applications, prepared film still exhibits Ud of 1 Jcm−3 with 90% efficiency, which is twice of the state-of-the-art BOPP. The results prove that the asymmetric ACA-PEA structure can greatly improve Ud of crosslinked polymer film while maintaining superior energy storage efficiency at high temperature. This work paves a new way for the material design of high-performance polymer film capacitor.

Jeffamine® ED‐600: a polyether amine donor for enzymatic transamination in organic solvent/solvent‐free medium with membrane‐assisted product extraction

AbstractBACKGROUNDAmine transaminases have been extensively used for synthesizing various pharmaceutically relevant compounds, mainly in aqueous media. However, their applications are often limited by poor substrate solubility, low productivity and difficult product separation. This paper reports the use of Jeffamine® ED‐600, a novel polyether amine donor, for the transaminase‐catalyzed synthesis of 4‐phenyl‐2‐butylamine in non‐aqueous media.RESULTSEnzymatic transamination was performed in the presence of a non‐polar organic solvent (n‐heptane), in which the selected amine donor is not soluble, thus a two‐liquid‐phase system was achieved. Coupling the reaction system with membrane‐assisted extraction resulted in simultaneous recovery of product, without any consistent contamination of the unreacted substrates. Moreover, a product yield of 60% was reached, compared with 15% without product extraction. The reaction was also successfully conducted without addition of any organic solvent, thus providing the first example of a solvent‐free transamination system. In the presence of only enzyme and substrates, up to 6‐fold higher product concentrations were achieved compared with the reaction performed in organic solvent.CONCLUSIONThe use of the Jeffamine® ED‐600 in non‐aqueous media resulted beneficial for 4‐phenyl‐2‐butylamine synthesis. Enzymatic transamination in organic solvent with membrane‐assisted product extraction enabled shifting of the equilibrium and selective product extraction. Solvent‐free transamination minimized the required volume of the reactor and minimized the environmental impact. Extension to other substrate/enzyme solvent‐free systems could open new possibilities and perspectives in transaminase‐catalyzed chiral amine synthesis. © 2019 Society of Chemical Industry

Jeffamine‐Based Polymers for Rechargeable Batteries

AbstractRechargeable batteries are important building blocks for a sustainable and electrified society thanks to their strong capability of storing electrical energies under chemical forms. JEFFAMINE®, a series of polyetheramines (PEAs) currently produced by Huntsman Corporation, has been emerging as a promising candidate for accessing high‐performance electrolytes and other cell components of rechargeable batteries. In this review, a brief history of the Jeffamine‐type PEAs and the synthetic chemistry of the Jeffamine‐based polymers are presented. The main applications of the Jeffamine‐based polymers in rechargeable batteries are discussed and highlighted, including various kinds of polymer electrolytes, polymeric binders, redox‐active materials, and interfacial layers stemming from the Jeffamine‐type PEAs. Lastly, future directions on the rational design of Jeffamine‐based materials are provided with the aim of improving the electrochemical performance of rechargeable batteries.

Synergistic Strengthening and Toughening the Interphase of Composites by Constructing Alternating “Rigid‐and‐Soft” Structure on Carbon Fiber Surface

AbstractInterphase with nacre‐like structured multilayer is constructed by alternatively depositing two polymers, respectively “rigid” polydopamine (PDA) and “flexible” polyether amine, on carbon fiber surface via the layer‐by‐layer (LbL) approach. The optimal interfacial strength and toughness are achieved for composites with three layers of PDA/polyether amine, respectively, 39.2% and 99.8% superior to the untreated fiber composites. The outstanding mechanical properties are mainly ascribed to the synergistic interactions of covalent bond, hydrogen bonding, and π–π stacking among fiber, multilayer, and matrix by transferring stress and bridging cracks, as well as the alternating “rigid and flexible” structure of interphase by deflecting crack path and inducing plastic deformation and viscoplastic energy dissipation. This work opens a new, feasible, and easy scalable avenue for constructing integrated high‐performance fiber composites.

Reactive toughening of intrinsic flame retardant urea-formaldehyde foam with polyether amine: Structure and elastic deformation mechanism

Polyether amine (PEA) was chemically introduced onto urea-formaldehyde (UF) chains for the purpose of toughening UF foams via reactions of PEA involved hydroxymethylation and condensation in UF system. Through introduction of PEA component, the curing process of UF-b-PEA proceeded within a broader temperature range, and the curing peak shifted to a higher temperature. Compared with neat UF foam, UF-b-PEA foams exhibited polygonal open cells with larger cell size, longer strut length and higher open porosity. During cyclic compression, the Mullins effect and the area in the hysteresis loop were reduced for UF-b-PEA foam, indicating outstanding compression resilience and compressive stability of the foam. Due to the open-cellular structure of foam and excellent flexibility of PEA component, the critical force of Euler buckling (Fc) decreased obviously, indicating the deformability of UF-b-PEA foams was improved without fracture of strut during reversible deformation. Besides, UF-b-PEA foams showed outstanding flame retardancy.

Hybrid Poly(hydroxy urethane)s: Folded-Sheet Morphology and Thermoreversible Adhesion.

Hybrid poly(hydroxy urethane)s (PHUs) are synthesized by copolymerizing aromatic/alicyclic cyclic carbonates with a polyether amine via addition polymerization. They result into polymers with an average molecular weight of 10 kDa and exhibit solubility in common organic solvents. The hybrid PHUs display Tg up to 18 °C. PHUs are enriched with multiple H-bonded interactions and they are assessed using temperature-dependent 1H NMR and Fourier-transform infrared studies. PHUs possess folded-sheet morphology with nanogap between folds and nanowidth between chains. The secondary interactions bestow thermoreversible property to PHUs, and they display good adhesion to both polar (Al–Al) and nonpolar (HDPE–HDPE) substrates. Hybrid PHUs show improved optical transparency compared to homo PHUs. The PHUs are thermally stable up to 250 °C.

Reductive amination of polypropylene glycol using Ni-CeO2@Al2O3 with high activity, selectivity and stability

Ni-only and Ni-CeO2 particles decorated on Al2O3 support material were prepared for an effective catalytic reductive amination of polypropylene glycol (PPG) to polyetheramines (PEA). Incipient wetness impregnation was employed for the preparation of catalysts followed by complementary material characterization (powder XRD, SEM, HRTEM, XPS, H2-TPR and NH3-TPD). High selectivity to PEA (~ 100%) was achieved. The catalytic activity obtained was proportional to Ni and Ce loadings (CCe), when CCe ≤ 15%. Hybridization with CeO2 inhibited formation of nickel nitride and enhanced activity (by 15.3%) and operation stability of Ni catalyst (by 20×). The present work has demonstrated a facile route to fabricate Ni-CeO2 hybrid catalysts on alumina support material and provided mechanistic understanding of the synergistic effect occurred for the heterogeneous catalytic reductive amination.

High performances polyurethane-urea polyacrylate hybrid emulsion coatings with multiple crosslinking structures

In this article, polyurethane-urea polyacrylate hybrid emulsions were synthesized via emulsion copolymerization of acrylate monomers, vinyltriethoxysilane (VTES) and anionic polyurethane-urea prepolymer with acrylate groups as the reactive emulsifier. Using waterborne polycarbodiimide as the crosslinker, room temperature multiple crosslinking hybrid coatings were fabricated successfully. Besides the crosslinking between polycarbodiimide and carboxyl groups, the polymerization crosslinking between polyurethane-urea and polyacrylate and the crosslinking of polyacrylate by VTES were confirmed by analyzing the crosslinking degree, FT-IR spectra and DSC curves. As more polycarbodiimide was used to consume hydrophilic carboxyl groups within the coatings, the water resistance increased considerably as well as the improvement in tensile strength. At polypropylene glycol and polyether amine molar ratio of 1:2, strengthening and toughening phenomenon were observed in tensile test of the hybrid films. At which the hybrid coatings demonstrated high impact strength and flexibility. However, higher weight ratios of methyl methacrylate and butyl acrylate resulted in brittle coatings.

Effects of preparation parameters on CO2/N2 gas permselectivity of polyether thin film composite membrane

ABSTRACTIn this work, ether oxide (EO)‐based multilayer composite membranes were prepared via interfacial polymerization (IP) of trimesoyl chloride (TMC) and polyetheramine (PEA) on polydimethylsiloxane precoated polysulfone support membrane. The effects of preparation parameters, such as monomer concentrations, reaction time, and heat‐treatment temperature on the membrane performance were investigated. The optimal preparation parameters have been concluded. The results showed the increasing monomers concentration of both PEA and TMC can lead to the decrease of CO2 permeance and increase of CO2/N2 selectivity. The optimal monomers concentration was found. When monomer concentrations are higher than the optimal values, the CO2 permeance decreases continually while CO2/N2 selectivity only shows a very limited improvement with the further increase of monomers concentration. The reaction time has similar effects on membrane performance as the monomers concentration. The effect of heat‐treatment temperature was also studied. With the increasing heat‐treatment temperature, the CO2 permeance shows a decrease tendency, while the CO2/N2 selectivity shows a maximum at 80 °C. When PEA is 0.013 mol L−1, TMC is 0.020 mol L−1, reaction time is 3 min, and heat‐treatment temperature is 80 °C, the optimum preparation conditions are achieved with CO2 permeance of 378.3 gas permeation unit (GPU) and CO2/N2 selectivity of 51.7 at 0.03 MPa. This work may help to design and fabricate gas separation membranes with desired performance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47755.

Hydraulic Abrasion-Resistant Elastic Epoxy Resin Materials

The abrasion of hydraulic concrete structures caused by the washing action of flowing water is a common problem and cannot be solved by simply increasing the strength of the concrete. To ensure safe operation, increase in service life and reduction of maintenance costs of hydraulic concrete structures and the development of abrasion-resistant materials are required. In this work, polyurethane-modified epoxy resin was synthesized using the interpenetrating network technology (IPN). After many mixing experiments, the ratio of polyether amine to alicyclic amine in Component B was determined to be 29 : 14 and the ratio of Component A to Component B was 7 : 3. With these ratios, elastic epoxy achieved a tensile strength of more than 15 MPa and an elongation rate of more than 20%, thus balancing strength and toughness. The effects of the curing conditions, the ratio of Component A to Component B, and diluents and fillers on tensile strength and elongation of the elastic epoxy resin were analyzed. The results of the analysis indicated that the curing duration should be over 7 days, the optimal proportion of Component A to Component B should be 7 : 3, and the diluent of the elastic epoxy material should be the bifunctional butanedioldiglycidyl ether (622). The reliability of this material was determined by pull-out testing, adhesion, and tensile strength testing. The underwater steel ball test and ring test were adopted as the abrasion-resistance tests for the elastic epoxy resin material. The results showed that the abrasion-resistance performance of elastic epoxy coating improved hundreds of times over that of common concrete. Although the wearing strength was reduced with pressure, the elastic epoxy coating still retained excellent abrasion-resistance performance. At last, future application prospects of elastic epoxy improvement products are introduced and need further reach.

A polyether amine modified metal organic framework enhanced the CO2 adsorption capacity of room temperature porous liquids.

Based on both the compatibility principle of similar polymeric structures and the steric interaction, a polyether amine (D2000) modified MOF (UIO-66) was dispersed into an ionic liquid with a polyether structure to form a new porous liquid (called the UIO-66-liquid) at room temperature. This unique UIO-66-liquid showed an outstanding CO2 uptake capacity among the existing porous liquids.

The Synthesis of Cationic Gelatin Derivative and its Effect on the Swelling of Sodium Bentonite

In this study, a cationic gelatin derivative (denoted as GCTA) was synthesized and its effect on the swelling of sodium bentonite (Na-BT) was investigated. The inhibitive properties of GCTA were evaluated through linear swelling test and hot-rolling recovery test. Results suggested that GCTA displayed better inhibitive ability than KCl and polyether amine (PEA). The underlying inhibitive mechanisms were also investigated by measuring interlayer spacing through X-ray diffraction, observing shale cuttings through scanning electron microscope and measuring the change of zeta potential of Na-BT dispersion. GCTA could strongly adsorb on the surface of clay particles and coat the particles. Meanwhile, the molecules entered the interlayer space, expelled water and decreased the interlayer spacing. This study can provide new insights into the design of environmentally friendly and highly effective clay inhibitors for water-based drilling fluids.

Y2O3-Inserted Co-Pd/zeolite catalysts for reductive amination of polypropylene glycol

Cobalt-based catalysts having different base strengths were prepared by controlling the amount of yttrium oxide (Y2O3). These catalysts were used for the facile one-pot synthesis of polyetheramine (PEA) from polypropylene glycol (PPG) through reductive amination. It is noticed that high hydrogen partial pressures up to 40 bar inhibit the formation of cobalt nitride and lead to a high PEA yield although it has been known that dehydrogenation from alcohol to ketone is the rate-determining step. The Y2O3-inserted Co-Pd/Molecular sieve13X catalyst also showed high activity toward PEA even at low hydrogen partial pressure. Y2O3 played a crucial role in giving basicity to the catalyst, which not only prevents the formation of cobalt nitride but also promotes hydrogenation of imine to amine at a wide range of H2 pressure. Thus Y2O3 inserted Co-Pd/Molecular sieve 13X provides unique performance toward enhancing the PEA yield while suppressing the catalyst deactivation caused by the cobalt nitride formation.