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For your adhesive formulations, employ DETA or TETA or their adducts work fine if you are looking for an adhesive to be cured at room temperature. These hardeners can cure your adhesives in 25 - 30 minutes. Some grades of polyamides may also work fine. Mercaptans and thiol hardeners can cure epoxy in 5 minutes at RT... What can increase the curing rate? it depends on your purpose, generally speaking, 1-elevated temperature, or 2- Accelerator (i.e., DMP-10, tertiary amines, up to 10 phr, etc.) can substantially increase the rate.

@@EpoxyChannel-yu9bu thanks so much for your reply, so kind of you. I forgot to mention that we want adhesive to cure at room temperature with in 30 mins specially for composition to composite adhesion. I have tried TETA 10% of epoxy but didn't cure. Can you suggest particular hardner with chemical name to cure epoxy at room temperature in 30 mins Thanks again. If i get your mail id that would be great 😃 , better communication. Cheers

@@DMMD697 Most welcome. My personal email is Arash.Jahandideh@gmail.com. inbox me and I can share more info. Deta and Teta have been formulated for fast cure, i.e., 25 minutes at ambient temperature. Dependants here are the fillers and additives you may have used in your system, the Temperature, and Humidity of the ambient where your adhesive is supposed to be cured, etc. Hundra percent success can be achieved if you use an accelerator of up to 10 % in your formulation or use faster hardeners. However, polyamides, amidoamines, and aliphatic amines are the most useful curing agent families for that purpose. These curing agents react directly with the epoxy and become part of the crosslinked epoxy structure, once cured. The polyamides and amidoamine curing agents provide flexibility and a degree of toughness to the cured epoxy. The aliphatic amines are somewhat more reactive and provide moderate temperature performance and good chemical resistance. However, they are generally more brittle than polyamides or amidoamines. Typical of the aliphatic amines are diethylene tetramine (DETA), triethylenetetramine (TETA), and catalytic amines such as DMP-30. For acceleration, you may try BF3-MEA or Accelerated mercaptanes Dion 3-800LC or EPI-Cure 861 for example, or accelerated amines, i.e., EPI-Cure 874... So many options you have here... if you use combination of polyamides with mercaptans, the Gel time would be 8 min at 23°C and Shear strength (aluminum-to-aluminum) would be equal to 2270 psi at 23°C. the former one has been added to add flexibility to your formulation.

Hey Khaled. Great suggestion! May look through it later. However, this would not be an easy task and the better strategy is to employ Chlorine free products, which are often used for electrical and electronic applications. Premium products which are supposed to be used for electrical potting are of such products, and are often a little more expensive. To omit traces amount of chlorine, often in ppm amounts from the ordinary epoxy is not an easy task... Source of Chlorine is the unreacted ECH in the Epoxy production.

@@EpoxyChannel-yu9bu Thanks for your kind reply. If it is possible can I get the references that you are explaining from. Actually I get huge benefits from your explanation.

@@EpoxyChannel-yu9bu I'm working now to prepare some of epoxy resin types at lab. So your lectures were very helpful for me. I want to take advices from you about preparing the epoxy at lab specially BPA.

@@KhaledQaswarah Thanks Khaled. Would be happy to help. Wish you luck!

Hey dear Sohaib, Your question is kind of vague to me, but let me explain the situation based on my understanding and plausible circumstances. The formulation: If you are formulating an adhesive product for example, technically you are mixing various compounds to achieve an adhesive (i.e., fillers, additives, etc.). Herein, the binder is a kind of epoxy, often 828 or 128 grades. If your binder and formulation is not changing then the EEW could have stayed in tact. The EEW is an inherent property of the epoxy (or the formulation) and be aware that unless there is a reaction occurs between oxiranes, it stays still. It means that in a formulation where reactions are not expected during mixing, EEW is a simple pointer to the oxirane rings. More, I am not sure about not achieving EEW on the same formulation. If you mean EEW of the formulation has varied, i.e., form 190 to 140 for example, it means that your Binder does not have the same quality as before, if other components and ratios of them are equal. You should check the EEW of your pristine Epoxy. If by achieving you mean measuring, as I explained, EEW is "not a function of weight of your formulation". So, as far as you are doing the measurement procedures right, you should end up with the same value. There are various standards exists for that. Did I answer your question?

Thanks for your kind words. I hope you enjoyed it and lets keep in touch.

Well noted. Will cover that subject also, after this general topic though. Starting with DETA adducts..

Thanks. Noted. will cover that topic in future videos.

Thanks for watching!

please communicate through my email and I see what is the situation you are exactly refereeing to. For now, be aware that there is a conflict between the type of hardener and the employed chemical, if you have used proper system.

@@EpoxyChannel-yu9bu please may you write your email address sir

@@EpoxyChannel-yu9bu please if you don't mind to write your email sir

@@EpoxyChannel-yu9bu please may you write your email address the we can discuss sir

Hello, thanks for your comment. You react ECH with Bis-A? or you add NaOH solution to the prepared epoxy-hardener solution? Explain your procedure and I will look through it.

If you want to react ECH with Bis-A to produce epoxy resin, you should be aware that the presence of NaOH may alter the reaction. One of the reactions of epichlorohydrin is hydrolysis with sodium hydroxide. This reaction produces glycerol and sodium chloride as the main products. The hydrolysis of epichlorohydrin is a step-growth polymerization that can produce linear or crosslinked polymers depending on the concentration of sodium hydroxide, the reaction temperature, and the dropping method . The lower the concentration of sodium hydroxide, the higher the yield of glycerol...

@@EpoxyChannel-yu9bu yes I am producing liquid epoxy resin based on bisphenol A and epichlorohydrin with NaOH as a catalyst. The application of this epoxy resin would be used in the coating field. The change of colour turns to yellow apear after adding the NaOH as a catalyst. Could you please give some advice to solve this problem

Hey Jaffar. Thanks for your explanation. Actually, there are crystal clear epoxy products on the market for the intended use... but if you want to synthesis the resin yourself, you should be aware of a few points. Firstly, the role of NaOH is to close the opened epoxy at the latest stages of the reaction, and as the reaction is thermodynamic equi, this kind of yellowing is investible. Even ordinary epoxy products at the market are kind of yellow. The premium products are crystal clear and have higher prices in the market. Moreover, be aware that the color often has little effect on the properties of the final product. If you wish to have a crystal clear product, First, you have to use super pure ECH and Bisphenol A and NaOH at the first step. Secondly, the whole reaction, even step 2, MUST be conducted under an inert gas blanket, say under nitrogen or argon gas. You should avoid oxygen, CO2, and humidity during the synthesis and avoid higher temperatures. Briefly, you should minimize oxidation. Metals can also result in yellow color in your product. The contact with metals, i.e., pipes, should be minimized. Finally, in the industry final product is often purified and color will be omitted. Distillation of the final product, again under nitrogen purge is another strategy you can count on... @@jafarrullahabdulaziz18

Your welcome. Enjoy!

Hello, Epichlorohydrin is a CARCINOGEN and MUTAGEN. HANDLE WITH EXTREME CAUTION. For safety and hazard associated to epoxy systems you can watch the video I have uploaded earlier. you can find some information about ECH there as well. For more details I suggest reading the document uploaded by EPA. check the link and stay safe: www.epa.gov/sites/default/files/2016-09/documents/epichlorohydrin.pdf

Thanks, yes. There would be a video on epoxies in composites. In these composites often carbon fibers, glass fibers or aramid fibers are employed. There are different techniques exist for their manufacturing. As the binder, DGEBA epoxies of n=0, Trifunctional MY 0510 or equivalents, and tetra functional resins such as MY 720, PGA X, etc., can be employed. I encourage you to watch the video as soon as it has been published. If you have further questions I would be glad to answer.

Most welcome!

Thanks.

Thanks. It is kind of odd...BTW, please try my personal email at Arash.Jahandideh@gmail.com. I hope I can help you.

Thanks for the tip.

Thanks for your support.