A phosphorus-containing imidazole derivative towards the liquid oxygen compatibility and toughness of epoxy resin

Abstract

Thermosets modified with a P-containing imidazole derivative (VAD) exhibited simultaneous liquid oxygen compatibility and excellent mechanical properties.

A vanillin derivative P/N/S‐containing high‐efficiency flame retardant for epoxy resin

“…It is distinct that there are two peaks at 28.79 and 30.26 ppm in the spectrum of VTZD, while DOPO exists only a single peak at 14.66 ppm. It is possible that rigid and bulky benzothiazole ring and DOPO group are present in the molecular structure of VTZD, and the steric hindrance effect may lead to the formation of stereoisomers with inequivalent phosphorus peaks in 31 P NMR spectra 35–37 . In summary, the above information well confirms the chemical structure of VTZD.…”

Renewable green reactive diluent for bisphenol a epoxy resin system: curing kinetics and properties

“…The FTIR spectrum (KBr) was collected with a Thermo Nicolet Nexus 6700 FTIR spectrometer instrument. 1 H-NMR spectra was obtained at room temperature on a 400 MHz AVANCE III NMR spectrometer in CDCl 3 with tetramethylsilane as internal reference. The viscosity of the EP/ HSI-EP-EU was measured by a Physica MCR-301 rotary rheometer, and the angular frequency were set from 0.1 to 100 rad s. The DSC measurement was conducted on a NETZSCH 214 instrument under a nitrogen ow rate of 20 mL min −1 atmosphere and samples were heated from 298.15 to 523.15 °C (25 to 250 °C) at heating rates of 5, 10, 15, 20, 25 K min −1 , respectively.…”

“…Epoxy resin and epoxy resin matrix composites 1 are widely used in aerospace, 2 building materials, 3 sports equipment, 4 biomaterials, 5 adhesives, 6 coatings 7 and other defense and civilian products, 8 due to their excellent adhesion, mechanical properties and thermal stability. 9 Compared with other thermosetting materials, epoxy resin has relatively good processing properties, but in fact the viscosity of epoxy resin is still high at room temperature, and researchers are also working to further improve the processing properties of epoxy resin.…”

Liquid Oxygen Compatibility and Ultra-Low-Temperature Mechanical Properties of Modified epoxy Resin Containing Phosphorus and Nitrogen

“…Liquid oxygen propellant tanks are the main weight reduction components as the tanks are of considerable weight and volume within large launch vehicles [ 4 , 5 ]. With the evolution of carbon-fiber-reinforced resin matrix composites (CFRP) and their large-scale application in aerospace engineering, the preparation of linerless composite liquid oxygen cryotanks has become an important trend in lightweight spacecraft [ 6 , 7 , 8 , 9 , 10 ]. The tank weights could be reduced by 20–40% if using CFRP instead of a conventional alloy material, because CFRP have low density, a superior specific modulus and strength and outstanding resistance to fatigue, which considerably improves the flight efficiency of the space vehicle [ 11 , 12 , 13 , 14 , 15 ].…”

“…However, risks exist, such as the fact that EP is likely to explode and spark if exposed to frictional heating, mechanical shock, collision, static electricity, etc., when present in a liquid oxygen environment [ 2 , 22 , 23 ]. In addition, the brittleness of EP will greatly increase, and impact resistance is reduced substantially in the cryogenic environment [ 6 , 24 , 25 ]. Therefore, endowing EP thermosets with prospective LOC and improved mechanical properties is urgently required in order to broaden its applications [ 26 ].…”