Effect of Various Curing Agents On the Chemical Stability of Epoxy Resins

CORROSION ◽  
1961 ◽  
Vol 17 (1) ◽  
pp. 11t-20t ◽  
Author(s):  
RONALD L. DeHOFF
Keyword(s):  
Molecular Weight ◽  
Chemical Stability ◽  
Epoxy Resins ◽  
Room Temperature ◽  
Low Molecular Weight ◽  
Curing Agent ◽  
Corrosion Prevention ◽  
Curing Agents ◽  
Outdoor Weathering ◽  
Better Than

Abstract The epoxy resins most widely used in corrosion prevention are liquids of low molecular weight which can be converted to hard, tough, chemically resistant polymers by the use of various curing agents. Unlike other thermosetting resins such as polyesters, the curing agents may produce chemical linkages in the final polymers that differ from those present in the uncured form. Hence, the properties of cured epoxy resins are likely dependent upon, and may even reflect the properties of the curing agent used. Some seven different epoxy resin systems were exposed to various chemical environments and evaluatd for changes in dimensional stability and flexural strengths over a six month period. From the data presented herein, only limited conclusions may be drawn. Heat cured systems fare better than room temperature cured systems in every case. Anhydride cured epoxy resins show greater resistance to outdoor weathering than amine cured systems. 5.4.5, 6.6.8

Fast Curing Epoxy and Episulfide Resins for Biomedical Applications

1987 ◽  
Vol 110 ◽  
Author(s):  
Ioannis N. Hadjinikolaou ◽  
James P. Bell ◽  
Larz Spangberg
Keyword(s):  
Bisphenol A ◽  
Physical Properties ◽  
Epoxy Resins ◽  
Biomedical Applications ◽  
Room Temperature ◽  
Diglycidyl Ether ◽  
Clinical Use ◽  
Curing Agent ◽  
Curing Agents

Epoxy resins have physical properties that make them suitable for dental and orthopaedic applications such as adhesives and cements. However, it has been observed that epoxy resins harden too slowly for clinical use when mixed with conventional curing agents, e.g. amines and polyamides. A new epoxy - diepisulfide - polyamide system has been developed which gels in 5 to 20 minutes at room temperature. The system consists of two parts: a polyamide curing agent, and a blend of the diepisulfide analog of diglycidyl ether of bisphenol A [DGEBA] dissolved in a mixture of epoxies of the DGEBA type.

scholarly journals Metal- and Oxidant-Free Photoinduced Aromatic Trifluoromethylation Performed in Aerated Gel Media: Determining the Effects on Yield and Selectivity

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 29 ◽  
Author(s):  
Alex Abramov ◽  
Hendrik Vernickel ◽  
César Saldías ◽  
David Díaz Díaz
Keyword(s):  
Molecular Weight ◽  
Room Temperature ◽  
Homogeneous Solution ◽  
Product Distribution ◽  
Blocking Effect ◽  
Low Molecular Weight ◽  
Metal Free ◽  
Potential Benefits ◽  
Media Concentration ◽  
Reaction Media

In this work we have investigated the potential benefits of using supramolecular gel networks as reaction media to carry out air-sensitive metal-free light-induced trifluoromethylation of six-membered (hetero)arenes under aerobic conditions. This reaction was performed at room temperature (RT) using sodium triflinate (CF3SO2Na, Langlois’ reagent) as a source of radicals and diacetyl as electron donor. The effects of confinement in gel media, concentration of reactants, and type of light source on yield and product distribution were evaluated and compared to the results obtained in homogeneous solution. Four different low molecular weight (LMW) gelators were employed in this study. The results confirmed the blocking effect of the gel medium against reaction quenching by external oxygen, as well as a certain control on the kinetics and selectivity.

Studies on Blended Polymers. VIII. Blending of Carboxy SBR and Vinylpyridine SBR

1969 ◽  
Vol 42 (3) ◽  
pp. 759-768
Author(s):  
H. Iino ◽  
M. Tsukasa ◽  
T. Nagafune ◽  
K. K. Sekaicho ◽  
Y. Minoura
Keyword(s):  
The State ◽  
Curing Agent ◽  
Mixing Ratio ◽  
Polymer Molecules ◽  
Curing Agents ◽  
Better Than

Abstract Blends of carboxy-SBR and vinylpyridine-SBR, in which interactions were expected to occur between the two types of polymer molecules, were prepared by different blending methods and with different vulcanizing systems, and the variation of their properties with varying mixing ratio was studied. Latex blending was compared with blending on the mill. Investigations were carried out for each blend type with (1) a common curing agent for both polymers, (2) curing agents that affect only one of the polymers, and (3) a combination of curing agents, each of which affects one of the polymers. To examine the state of mixing, the blends were dyed and observed under the microscope. It was found that latex blending gave sufficiently good mixing to enable the interactions between the two polymers to influence the properties strongly, the blending being better than that achieved on the mill. However, when a combination of curing agents that affected the polymers singly was used, the effects of the interactions was no longer observed.

Room-temperature Sinterable Silver Nanoparticle Ink with Low-molecular-weight Poly(N-vinylpyrrolidone) Ligand

2013 ◽  
Vol 42 (3) ◽  
pp. 232-234 ◽  
Author(s):  
Mi Yeon Lee ◽  
Won Jin Lee ◽  
Arup Kumer Roy ◽  
Kang Seok Lee ◽  
Sung Young Park ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Silver Nanoparticle ◽  
Room Temperature ◽  
Low Molecular Weight ◽  
Nanoparticle Ink

Effect of Molecular Weight on Phase Diagram of Epoxy/Polyetherimide-Siloxane Blends

2011 ◽  
Vol 189-193 ◽  
pp. 1127-1131
Author(s):  
Xiao Yan Li ◽  
Wen Jun Gan ◽  
Yuan Ren ◽  
Zheng Xi ◽  
Ye Wen Tang ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Molecular Weight ◽  
Cloud Point ◽  
Epoxy Resins ◽  
Optical Microscope ◽  
Curing Agent ◽  
Curing Time ◽  
Point Curve ◽  
Cloud Points ◽  
Cloud Point Curve

The cloud points of blends epoxy/polyetherimide-siloxane (PEI-Siloxane) without or with curing agent methyl tetrahydrophthalic anhydride (Me-THPA) after different curing time (1min, 2min, 3min) at 150oC were determined by optical microscope. The cloud point curve for uncured and cured after different time was then obtained from the experimental results with different composition. The effects of molecular weight of epoxy on phase diagram were discussed. The miscibility of blends will be taken into account in the toughing of epoxy resins by thermoplastic PEI-Siloxane copolymer later.

Influence of low molecular weight tail of polypropylene resin on the pore structure by room-temperature stretching

2013 ◽  
Vol 53 (12) ◽  
pp. 2594-2602 ◽  
Author(s):  
Lei Caihong ◽  
Wu Shuqiu ◽  
Xu Ruijie ◽  
Peng Xinlong ◽  
Shi Wenqiang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Pore Structure ◽  
Room Temperature ◽  
Low Molecular Weight

The diffusion of low molecular weight substances into epoxy resins as a function of their molecular weight

1975 ◽  
Vol 17 (6) ◽  
pp. 1489-1497 ◽  
Author(s):  
S.A. Nenakhov ◽  
A.Ye. Chalykh ◽  
A.T. Sanzharovskii
Keyword(s):  
Molecular Weight ◽  
Epoxy Resins ◽  
Low Molecular Weight

Solvent Exchange to Exfoliate Graphene Oxides into Epoxy with Improved Mechanical and Thermal Properties

2015 ◽  
Vol 1110 ◽  
pp. 69-72
Author(s):  
Fu Ke Wang ◽  
Chao Bin He
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Mechanical And Thermal Properties ◽  
Curing Agent ◽  
Solvent Exchange ◽  
Thermal And Mechanical Properties ◽  
Graphene Oxides ◽  
Curing Agents ◽  
Exchange Technique

The dispersion and exfoliation of graphene oxides in polymer matrix remains a challenge for graphene oxides based epoxy nanocomposites fabrication. In the present paper, we reported a simple and facile solvent exchange technique to successfully transfer graphene oxides (GOs) from aqueous solution to ethanol. In addition, we found that GO dispersion in epoxy resins was affected by the curing agents. Good dispersion of GOs in epoxy resin together with enhanced thermal and mechanical properties were observed when epoxy was cured with aliphatic curing agents. For aromatic curing agent, high loading of GOs leaded to GOs aggregation, but well dispersed GOs was observed at low loading of GOs. Especially, a 12 °C increase of glass transition temperature of the epoxy resin was observed with only 0.1 wt% GOs was added to the epoxy resin.

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