Modification of amine-cured epoxy resins by boronic acids based on their reactivity with intrinsic diethanolamine units

2018 ◽  
Vol 54 (92) ◽  
pp. 12930-12933 ◽  
Author(s):  
Yumiko Ito ◽  
Jumpei Kida ◽  
Daisuke Aoki ◽  
Hideyuki Otsuka
Keyword(s):  
Epoxy Resins ◽  
Boronic Acids ◽  
Epoxy Polymers

Amine-cured epoxy polymers were modified after curing, exploiting the reactivity of their intrinsic diethanolamine units toward boronic acids.

Natural Climatic Aging of Epoxy Polymers Taking into Account the Seasonality Impact

2019 ◽  
Vol 799 ◽  
pp. 159-164
Author(s):  
Dmitrii R. Nizin ◽  
T.A. Nizina ◽  
V.P. Selyaev ◽  
A.N. Chernov ◽  
A.I. Gorenkova
Keyword(s):  
Salicylic Acid ◽  
Epoxy Resins ◽  
Total Duration ◽  
Variable Parameter ◽  
Natural Aging ◽  
Strength Properties ◽  
Time Intervals ◽  
Epoxy Polymers ◽  
Low Viscosity ◽  
First Time

The change in the elastic-strength and sorption properties of epoxy polymers in the process of natural aging, taking into account the sequence of different climatic seasons effects, was studied. We studied polymers obtained on the basis of low-viscosity epoxy resins and a hardener, which is a mixture of aromatic and aliphatic di-and polyamines, modified by salicylic acid. Differences in the processes of structural relaxation and elimination of the initial nonequilibrium depending on the season of the exposure start are revealed. Mathematical models that describe changes in the elastic-strength properties of epoxy polymers during climatic aging, depending on the accumulated quantitative values ​​of the acting environmental factors, have been developed. For the first time, it was proposed to use as a variable parameter the total duration of time intervals for the studied period the surface temperature of the samples at which exceeded the glass transition temperature.

Functionalization of amine-cured epoxy resins by boronic acids based on dynamic dioxazaborocane formation

2020 ◽  
Vol 11 (33) ◽  
pp. 5356-5364 ◽  
Author(s):  
Yumiko Ito ◽  
Daisuke Aoki ◽  
Hideyuki Otsuka
Keyword(s):  
Boronic Acid ◽  
Epoxy Resins ◽  
Boronic Acids

Functionalization of epoxy resins after curing was performed based on dynamic dioxazaborocane formation between intrinsic diethanolamine units in amine-cured epoxy resins and boronic acid modifiers.

scholarly journals PROPERTIES OF COMPOSITIONAL MATERIALS BASED ON THE MIXTURES OF EPOXY POLYMERS AND OLIGOSULFONES. PART 3. PHYSICO-MECHANICAL PROPERTIES

2019 ◽  
pp. 101-111 ◽  
Author(s):  
Ю. Кочергин ◽  
Y. Kochergin ◽  
В. Золотарёва ◽  
V. Zolotareva
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Epoxy Resins ◽  
Chemical Nature ◽  
Epoxy Polymer ◽  
Physical And Mechanical Properties ◽  
Strength Properties ◽  
Polymer Materials ◽  
Epoxy Polymers ◽  
Structural Purpose

The influence of modifying additives of oligosulfones of different molecular weight with terminal carboxyl and phenolic groups on the physical and mechanical properties of epoxy polymers is investigated. It is found that the modification allows to increase the tensile strength by 32, the deformation at break by 85, the modulus of elasticity by 47 and the failure rate by 123 %. The maximum set of properties is realized when the epoxy polymer is introduced into the composition of 3–5 wt. с. of oligosulfone with a molecular weight of 4700. It is shown that the magnitude of the effect depends significantly on the amount of the modifier introduced and its molecular weight. The chemical nature of the end groups has little effect on the basic deformation and strength properties. The results of the work allow to recommend the studied oligosulfonsfones for the production of composite polymer materials of structural purpose with improved physical and mechanical properties on the basis of epoxy resins.

Epoxy Resin Embedment

1968 ◽  
Vol 26 ◽  
pp. 100-101
Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Epoxy Resin ◽  
Light Microscope ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Tissue Preservation ◽  
Resin System ◽  
Excellent Quality

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).

Technical notes on routine TEM procedures

1987 ◽  
Vol 45 ◽  
pp. 630-631
Author(s):  
K. Chien ◽  
R.L. Van de Velde ◽  
R.C. Heusser
Keyword(s):  
Epoxy Resins ◽  
Pathology Laboratory ◽  
Silicone Fluid ◽  
Image Position

Sectioning quality of epoxy resins can be improved by the addition of a 1% silicone 200 fluid (Dow Corning), however this produces a softer block. To compensate, a harder plastic has been used for embedding various tissues encountered in our pathology laboratory. Exact amounts of the plastic mixture can be directly made up for embedding as shown: The chart reveals a Poly/Bed 812 (WPE 145) to anhydride ratio of 1:0.7 and a NMA to DDSA ratio of 7:3. 1% silicone fluid is added to above mixtures.Due to impurities within the DDSA and NMA, the polymerized epoxy blocks vary in darkness and appear to affect sectioning quality. After discussing this problem with Polysciences Inc., they have agreed to purify their anhydrides in an effort to standardize the consistency of the plastic.

Stain contamination and embedding in electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 50-53
Author(s):  
Hilton H. Mollenhauer
Keyword(s):  
Electron Microscopy ◽  
Information Retrieval ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Sample Preservation ◽  
Factors Associated ◽  
Amount Of Information ◽  
Electron Microscopical ◽  
Contrast Information

Many factors (e.g., resolution of microscope, type of tissue, and preparation of sample) affect electron microscopical images and alter the amount of information that can be retrieved from a specimen. Of interest in this report are those factors associated with the evaluation of epoxy embedded tissues. In this context, informational retrieval is dependant, in part, on the ability to “see” sample detail (e.g., contrast) and, in part, on tue quality of sample preservation. Two aspects of this problem will be discussed: 1) epoxy resins and their effect on image contrast, information retrieval, and sample preservation; and 2) the interaction between some stains commonly used for enhancing contrast and information retrieval.

Reliable Bonding of Composite Laminates Using Reflowable Epoxy Resins

2019 ◽  
Author(s):  
Frank Palmieri ◽  
Tyler Hudson ◽  
Roberto Cano ◽  
Erik Tastepe ◽  
Dean Rufeisen ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Epoxy Resins

A Mild and Simple Method for Making MIDA Boronates

2020 ◽  
Author(s):  
Aidan Kelly ◽  
Peng-Jui (Ruby) Chen ◽  
Jenna Klubnick ◽  
Daniel J. Blair ◽  
Martin D. Burke
Keyword(s):  
Organic Synthesis ◽  
Boronic Acids ◽  
Simple Method ◽  
Direct Preparation ◽  
Synthesis Procedure ◽  
Harsh Conditions

<div> <div> <div> <p>Existing methods for making MIDA boronates require harsh conditions and complex procedures to achieve dehydration. Here we disclose that a pre-dried form of MIDA, MIDA anhydride, acts as both a source of the MIDA ligand and an in situ desiccant to enable a mild and simple MIDA boronate synthesis procedure. This method expands the range of sensitive boronic acids that can be converted into their MIDA boronate counterparts. Further utilizing unique properties of MIDA boronates, we have developed a MIDA Boronate Maker Kit which enables the direct preparation and purification of MIDA boronates from boronic acids using only heating and centrifuge equipment that is widely available in labs that do not specialize in organic synthesis. </p> </div> </div> </div>

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