Esterification synthesis of ethyl oleate catalyzed by Brønsted acid–surfactant-combined ionic liquid

Xie

et al. 2018

Macro Materials & Eng

Self Cite

A new monomer called 2,2′‐(4,4′‐oxydiphenol‐4,4′‐diyl)bis(2‐methyl‐2,3,3a,4,7,7a‐hexahydro‐1H‐4,7‐methanoisoindol‐2‐ium) iodide (d3) is synthesized possessing both cross‐linker and functional groups. The membranes are formed by copolymerizing d3 with norbornene and (3aR,4S,7R,7aS)‐2‐methyl‐2‐(3‐(trimethylammonio)propyl)‐2,3,3a,4,7,7a‐hexahydro‐1H‐4,7‐methanoisoindol‐2‐ium iodide (a3) at varying ratios. The water uptake is 41.35% at 60 °C, and ion exchange capacity is 2.35 mequiv g−1 for a mole ratio of a3, norbornene, and d3 (1:6:3). The conductivity is 12, 37, and 40 mS cm−1 when d3 is decreased. Meanwhile, the conductivity increases quickly with increasing the temperature. Furthermore, the mechanical properties and thermal properties are improved, attributed to the increased cross‐linker. The membrane has a tensile strength of 41.3 MPa and the elongation at break of 38.0 %, and the 5 wt% loss temperature for membrane is ≈159 °C. The H2/O2 single fuel cells with this membrane show a maximum power density of 124 mW cm−2 at 50 °C. The cross‐linked membranes demonstrate high‐dimensional stability in alkaline solution.

Section: Introductionmentioning

confidence: 99%

Controllable Cross‐Linking Anion Exchange Membranes with Excellent Mechanical and Thermal Properties

Xie

et al. 2018

Macro Materials & Eng

Self Cite

“…Using a synergistic effect between 2 fillers can be an efficient way to tackle these problems, as reported in other systems, such as nanomagnetite and carbon nanofiber, CNTs and graphene, and carbon black and CNTs . A compatibilizer has usually been used to improve the compatibility between nanofillers and the polymer matrix, including maleic anhydride grafted HDPE, ethylene‐vinyl acetate (EVA) copolymer, and ethyl oleate . EVA is suitable as a compatibilizer because it is a kind of thermoplastic material that consists of vinyl monomer and vinyl acetate (VA) monomer.…”

Section: Introductionmentioning

confidence: 99%

Preparation of antistatic high‐density polyethylene composites based on synergistic effect of graphene nanoplatelets and multi‐walled carbon nanotubes

Polymers for Advanced Techs

et al. 2017

Graphene nanoplatelets are promising candidates for enhancing the electrical conductivity of composites. However, because of their poor dispersion, graphene nanoplatelets must be added in large amounts to achieve the desired electrical properties, but such large amounts limit the industrial application of graphene nanoplatelets. Multi-walled carbon nanotubes also possess high electrical conductivity accompanied by poor dispersion. Therefore, a synergistic effect was generated between graphene nanoplatelets and multi-walled carbon nanotubes and used for the first time to prepare antistatic materials with high-density polyethylene via 1-step melt blending. The synergistic effect makes it possible to significantly improve the electrical properties by adding a small amount of untreated graphene nanoplatelets and multi-walled carbon nanotubes and increases the possibility of using graphene nanoplatelets in industrial applications. When only 1 wt% graphene nanoplatelets and 0.5 wt% multi-walled carbon nanotubes were added, the surface and volume resistivity values of the composites were much lower than those of the composites that were only added 3 wt% graphene nanoplatelets. Additionally, as a result of the synergistic effect of graphene nanoplatelets and multi-walled carbon nanotubes, the composites met the requirements for antistatic materials.

“…The SEM and FTIR results indicated that the flame‐retardant mechanism of DPPM in RPUF was the forming of intact and continuous char layer on the surface of RPUF in thermal degradation of the composite, which prevented the heat and mass transfer between the gas and the condensed phases and effectively protected the substrate material from burning. These flame retardants can be extended for multifunctional polymer nanocomposites with an aim to broaden the applications of inert polymers especially in the form states in the fields such as electromagnetic interference shielding, energy storage and other sensing applications …”

Section: Discussionmentioning

confidence: 99%

“…Traditionally, the main flame retardants for RPUF are the halogen‐based compounds such as pentabromodiphenyl ether, chloroethylphosphate, etc, which may endow RPUF excellent flame retardation . However, when burning, such retardants release a lot of toxic gases which pollute environment and damage people's health . Thus, the environmentally‐friendly flame‐retardant additives with good flame retardancy are particularly needed.…”

Section: Introductionmentioning

confidence: 99%

Flame‐retardant rigid polyurethane foam with a phosphorus‐nitrogen single intumescent flame retardant

Polymers for Advanced Techs

et al. 2017

Self Cite

232

138

A phosphorous-nitrogen intumescent flame-retardant, 2,2-diethyl-1,3-propanediol phosphoryl melamine (DPPM), was synthesized and characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Flame-retardant rigid polyurethane foams (RPUFs) with DPPM (DPPM-RPUF) as fire-retardant additive were prepared. Scanning electron microscope (SEM) and mechanical performance testing showed that DPPM exhibited a favorable compatibility with RPUF and negligibly negative influence on the mechanical properties of RPUF. The flame retardancy of DPPM on RPUF was investigated by the limiting oxygen index (LOI), vertical burning test and cone calorimeter. The LOI of DPPM-RPUF could reach 29.5%, and a UL-94 V-0 rating was achieved, when the content of DPPM was 25 php. Furthermore, the DPPM-RPUF exhibited an outstanding water resistance that it could still obtain a V-0 rating after water soaking. Thermogravimetric analysis showed that the residual weight of RPUF was relatively low, while the charring ability of DPPM-RPUF was improved greatly. Real-time Fourier transform infrared spectroscopy was employed to study the thermo-oxidative degradation reactions of DPPM-RPUF. The results revealed that the flame-retardancy mechanism of DPPM in RPUF was based on the surface charred layer acting as a physical barrier, which slowed down the decomposition of RPUF and prevented the heat and mass transfer between the gas and the condensed phases. storage and electromagnetic interference shielding fields due to its high mechanical properties, insulated properties, etc. 1-4 However, one of its major defects is its flammability, which limits its further applications. 5,6 The improvement of the flame retardancy of RPUF has currently been an important subject among the developments of new polymer foam materials. 7,8 Traditionally, the main flame retardants for RPUF are the halogen-based compounds such as pentabromodiphenyl ether, chloroethylphosphate, etc, which may endow RPUF excellent flame retardation. 9 However, when burning, such retardants release a lot of toxic gases which pollute environment and damage people's health. 10-14 Thus, the environmentally-friendly flame-retardant additives with good flame retardancy are particularly needed. In recent years, the phosphorus-nitrogen intumescent flame retardants (IFR) have been widely used as halogen-free additives because they provide excellent fire protection with less smoke and lower toxicity. 15,16 Traditional IFRs are mixtures, which usually consist of an acid source (eg, ammonium polyphosphate), a carbonizing agent (eg, pentaerythritol, sorbitol) and a foaming agent (eg, melamine). The IFRs system usually experiences an intense expansion and forms protective charred layers that serve as a physical barrier to protect the underlying material from flux or flame. 14,15 In spite of many advantages, IFRs have 2 issues, ie, low water solubility and high thermal stability. 17 In addition, they are poorly compatible with the RPUF matrix, which weakens the mechanical properties of ...