Search results for "epoxy"

Crystal structure of the diglycidyl ether of eugenol

2017

The diep­oxy monomer (DGE-Eu) was synthesized from eugenol by a three-step reaction. It consists of a 1,2,4-tris­ubstituted benzene ring substituted by diglycidyl ether, a meth­oxy group and a methyl­oxirane group. The three-membered oxirane rings are inclined to the benzene ring by 61.0 (3) and 27.9 (3)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to the ab plane.

Unusual Regioselectivity in the Opening of Epoxides by Carboxylic Acid Enediolates

2008

Addition of carboxylic acid dianions appears to be a potential alternative to the use of aluminium enolates for nucleophilic ring opening of epoxides. These conditions require the use of a sub-stoichiometric amount of amine (10% mol) for dianion generation and the previous activation of the epoxide with LiCl. Yields are good, with high regioselectivity, but the use of styrene oxide led, unexpectedly, to a mixture resulting from the attack on both the primary and secondary carbon atoms. Generally, a low diastereoselectivity is seen on attack at the primary center, however only one diastereoisomer was obtained from attack to the secondary carbon of the styrene oxide.

Synthesis, structural, and thermal characterization of a new binuclear copper(II) chelate complex bearing an amine-hardener for epoxy resins

2016

A new di(μ-carbonato)bis[aqua(diethylenetriamine)copper(II)] hexahydrate complex, [{Cu(NH(C2H4NH2)2)(H2O)(μ-CO3)}2]⋅6H2O (1), was synthesized by direct interaction of malachite with diethylenetriamine (dien). The crystals of 1 were characterized by X-ray powder diffraction and IR spectra, as well as structurally characterized. Compound 1 consists of [{Cu(dien)(H2O)(μ-CO3)}2] discrete units whose CO32– anions play the role of bridging ligands combining two Cu(II) chelate cores into a centrosymmetric dimer. The elongated octahedral environment of Cu2+ consists of three nitrogens of dien and an oxygen from CO32– at the base of the bipyramid; the two apical positions of such polyhedron are occu…

Synthesis od epoxy/carbon fiber composites induced by e-beam. Study of the effect of hydrothermal ageing on thermal and mechanical properties

2010

Influence of Polymer Electrospun Nanofibers on Thermal Properties of Epoxy Resins

2019

Electrospinning of polymers has gained surging interest in the last decades due to its wide range of applications in different fields, such as sensors, electronic devices, separation systems, biomedical materials. Still there are only few reports on the use of these nanofibers as reinforcement in polymer composites. In this paper, solution electrospinning was employed to produce nanofibrous mats impregnating two epoxy resins to form “monolayer“ systems, with the aim to study the influence of the nanofibers on both the curing behaviour and the morphology of the resin systems. Three polymers were chosen for producing electrospun mats, a polysulfone (PSF), a polyamide Nylon 6,6 (Ny66) and a po…

Unexplored nucleophilic ring opening of aziridines.

2010

The reactivity of dianions of carboxylic acids towards aziridines has been studied. Although, a similar reactivity to that of enolates from ketones, esters or amides has been observed, the method directly yields g-aminoacids in one step. The method is complementary of previous results of enenediolate reactivity with other electrophiles. A comparative study with the reactivity of this enediolates with epoxides is included.

EPOXY RESIN SYSTEMS CURABLE BY HIGH ENERGY RADIATION FOR ADVANCED COMPOSITES. STUDY OF THE EFFECTS OF PROCESS TEMPERATURE ON THERMAL PROPERTIES

2006

EPOXY RESIN VS BIOCERAMIC: SYSTEMATIC REVIEW WITH META-ANALYSIS

2021

Radiation Curing of Thermosetting- Thermoplastic Blends as Matrices for Structural Carbon Fibre Composites

2011

Reduction-oxidation dynamics of oxidized graphene: Functional group composition dependent path to reduction

2018

Micrometer-sized oxidation patterns containing varying composition of functional groups including epoxy, ether, hydroxyl, carbonyl, carboxyl, were created in chemical vapor deposition grown graphene through scanning probe lithography and pulsed laser two-photon oxidation. The oxidized graphene films were then reduced by a focused x-ray beam. Through in-situ x-ray photoelectron spectroscopy measurement, we found that the path to complete reduction depends critically on the total oxygen coverage and concentration of epoxy and ether groups. Over the threshold concentrations, a complex reduction-oxidation process involving conversion of functional groups of lower binding energy to higher bindin…