Studies on curing of epoxy resins. XVIII. Effect of catalysts on the curing reaction of an epoxy resin with polymercaptans.

1988 ◽  
Vol 45 (10) ◽  
pp. 755-759 ◽  
Author(s):  
Takashi KAMON
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
Curing Reaction

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).

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

scholarly journals An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2205
Author(s):  
Qian Li ◽  
Yujie Li ◽  
Yifan Chen ◽  
Qiang Wu ◽  
Siqun Wang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Decomposition Temperature ◽  
Ease Of Use ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
Low Viscosity ◽  
The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

Thermal Stabilities and the Thermal Degradation Kinetics Study of the Flame Retardant Epoxy Resins

2014 ◽  
Vol 1053 ◽  
pp. 263-267 ◽  
Author(s):  
Xiu Juan Tian
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Thermal Stabilities ◽  
Degradation Kinetic ◽  
Modified Epoxy

Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.

Ozone Resistance of Vulcanizates Based on XNB Rubber

2021 ◽  
Vol 410 ◽  
pp. 686-691
Author(s):  
Evgeniy S. Bochkarev ◽  
Dmitriy S. Vostrikov ◽  
Oleg O. Tuzhikov
Keyword(s):  
Epoxy Resin ◽  
Magnesium Oxide ◽  
Polyvinyl Chloride ◽  
Flow Rate ◽  
Epoxy Resins ◽  
Butadiene Rubber ◽  
Express Method ◽  
Elastomeric Materials ◽  
Main Period ◽  
Ozone Resistance

The paper represents ozone resistance of rubbers based on carboxylated nitrile butadiene rubber cured with epoxy resins and magnesium oxide. Ozone resistance was investigated using the express-method at a flow rate of the ozone-air mixture of 9 l/h and ozone content of 9 mg/l. In the method used, the “time to cracking start” indicator was taken as the basic indicator of ozone resistance. The second indicator characterizing the ozone resistance of elastomeric materials was the "rate of destruction" in the main period of destruction. There has been evaluated the effect of dissolved polyvinyl chloride in epoxy resin ED-20 on the properties of vulcanizates. There has been investigated the Increase in destruction time under the action of ozone.

Epoxy resin curing reaction studied by proton multiple-quantum NMR

2015 ◽  
Vol 53 (18) ◽  
pp. 1324-1332 ◽  
Author(s):  
Mario Martin-Gallego ◽  
Antonio González-Jiménez ◽  
Raquel Verdejo ◽  
Miguel Angel Lopez-Manchado ◽  
Juan Lopez Valentin
Keyword(s):  
Epoxy Resin ◽  
Multiple Quantum ◽  
Curing Reaction ◽  
Resin Curing ◽  
Multiple Quantum Nmr

Synthesis of Three Novel Aromatic Biazomethine Liquid- Crystalline Epoxy Resins and Curing Reaction with Aromatic Diamine

2011 ◽  
Vol 216 ◽  
pp. 34-38
Author(s):  
Jun Gang Gao ◽  
Xiao Na Zhang ◽  
Yong Gang Du
Keyword(s):  
Melting Point ◽  
Epoxy Resins ◽  
Liquid Crystalline ◽  
Diphenyl Ether ◽  
Hydroxyl Group ◽  
Aromatic Diamine ◽  
Curing Reaction ◽  
Ozawa Equation ◽  
Liquid Crystalline Epoxy ◽  
Clearing Temperature

Three class of novel liquid crystalline epoxy resins containing azomething groups: N,N’-Bis[4-(2,3-epoxypropoxy)benzylidene]-4,4-diamino-diphenyl ether (p-BEPBDDE), N,N’-Bis[4-(2,3-epoxypropoxy)benzylidene]-4,4-diamino-diphenyl methane (p-BEPBDDM) and N,N’-Bis[(4-(2,3-epoxypropoxy)-benzyliden)-1,4- phenylene diamine] (p-BEPBPD) were synthesized and characterized. The results show that p-BEBDDE and p-BEBDDM belong to smectic texture and melting point is 239.5 and 178 oC, respectively. The p-BEPBD is nematic texture between its melting temperature (Tm) of 192 oC and clearing temperature (Ti) of 238 oC. The curing reaction can be described by Ozawa equation, and the alcohol-hydroxyl group can accelerate the curing reaction and decrease Ea in DSC experiment.

scholarly journals Investigation of the properties of composite materials based on epoxy resins with microsilica additives

2021 ◽  
Vol 318 (3) ◽  
pp. 63-70
Author(s):  
M.A. Serekpayeva ◽  
◽  
G.А. Kokayeva ◽  
R.K. Niyazbekova ◽  
S. Kardybai ◽  
...  
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Corrosion Protection ◽  
Epoxy Resins ◽  
Machine Maintenance ◽  
Resistance Increase ◽  
Dispersed Filler ◽  
Filler Particles

The outcomes of studying epoxy-based composite materials supplemented with microsilica are provided in the article. Microsilica was used as a filler. The samples were produced on the epoxy ED-20 basis supplemented with 2, 5 and 10 mas. % of microsilica. The structure and size of finely dispersed filler particles were defined. The obtained composites were tested for resistance to the effect of variable temperatures, corrosive, and abrasion. The study outcomes proved that samples supplemented with 2% of microsilica are more resistant to acid and alkali as well as to petrol than those ones supplemented with 25% of microsilica. Besides the amount of the filler from 2 to 10% doesn’t sufficiently affect the resistance to variable temperatures. When microsilica is added to epoxy resin, it causes scuff resistance increase. The conducted testing proved that the developed composite materials are resistant to the effect of variable temperatures, corrosive, and abrasion. This enables to use these materials as coatings and anti-corrosion protection during machine maintenance.

scholarly journals Gas Turbine Installation and Foundation Repair With Epoxy Resins

1983 ◽  
Author(s):  
J. Murray Wilson
Keyword(s):  
Epoxy Resin ◽  
Gas Turbine ◽  
Thermal Insulation ◽  
Epoxy Resins ◽  
Cement Grouts ◽  
Turbine Installation ◽  
Interface Designs

Epoxy resins are not just replacements for concrete and cement grouts, they offer the opportunity for completely new foundation/gas turbine interface designs. As a substitute for steel chocks, epoxy resin ones give perfect fit, high holding force and good thermal insulation, while eliminating the need for soleplates or rails.

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