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Post by joniverson on Feb 12, 2022 7:08:10 GMT -8
The need for a solvent in order to mix up some polystyrene glue recently got me to thinking about ethyl acetate, which I at one time used for leps. I came across a prior thread here suggesting that the "MEK substitute" contained mostly ethyl acetate with the remainder being acetic acid:
Since I have a need for the solvent for other purposes, I thought I might ask for confirmation of this before I actually place an order with my local Lowe's: is the MEK substitute they carry actually ethyl acetate and is the acetic acid content significant enough to affect performance? After prior searching here, I see that some folks apparently had purchased it, but never got back with test results.
Thank you!
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Post by vabrou on Feb 12, 2022 8:16:16 GMT -8
Jasco MEK Substitute says it is 100% Ethyl acetate. Found at Lowes in the USA cost ~$25.00. Probably a good deal if one is looking for a easy supply of Ethyl acetate. Though this chemical causes necrosis of the liver, you should know it is a long approved food additive e.g. used as pineapple flavoring in small amounts. I have written about Ethyl acetate numerous times as I use to purchase EA in 55 gallon drums and 5 gallon pails since the early 70's Makes a good bait for attracting butterfies (nymphalids) into automatic capture traps. Only problem it requires replenishing daily as it rapidly evaporates, which is how it attracts butterflies.
Please excuse my occasional typos, being treated for multiple and repeated corneal eye abrasion and just completed 4 sessions of extremely painful Laser eye surgery. Don't want to go through that again !!! My other excuse is I am old.
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Post by coloradeo on Feb 12, 2022 8:16:23 GMT -8
I buy it whenever I find it at Lowes and I use it consistently. I cannot perceive any issues from it, although I am not a chemist nor a professional.
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Post by vabrou on Feb 12, 2022 8:30:23 GMT -8
The mention of acetic acid is due to the creation of ethyl acetate occurs by the combination of acetic acid and ethanol. I have use this chemical (EA) for the past half century much of my use was daily, and I still have my liver. But if you have ever eaten something with pineapple flavoring, no doubt you have eaten EA.
As a Polystyrene glue, some things that would bind polystyrene may not affect this at at. Does 'model airplane glue' work for your application? That is commonly available on the web.
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Post by joniverson on Feb 12, 2022 8:47:04 GMT -8
This works. By mixing styrofoam pieces with this, you end up with pretty much the same glue as what's known on the market as "Q Dope" which is used for certain things in electronics, like keeping coil windings in place and such. I had already mixed up some, but used acetone as I didn't have any of this available, but the acetone and styrofoam, although the latter readily dissolves, end up not mixing all that well. According to my sources, the ethyl acetate is the best solvent for this with the benefit that if I restart my lep hobby, stopped since covid, I'll have an alternative killing method. Since I didn't have any, I usually just placed everything in the freezer for 20 min or so.
Thanks to you all for confirming, just placed a pick up order with Lowe's. I don't think in my lifetime, I'll ever use it all but it will be nice to have at a decent price.
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Post by colin12303 on Feb 12, 2022 10:48:53 GMT -8
I have just read ethyl acetate occurs by the combination of acetic acid and ethanol. If that is the case what are the ratios so i can make my own. You can easily buy acetic acid in the form of white vinegar,and as i have a vintage motor bike that should not be run on E10 unleaded fuel i have built something to extract the ethanol from the petrol.
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Post by jhyatt on Feb 12, 2022 15:22:35 GMT -8
Colin12303:
Ethyl acetate is indeed made from ethanol and acetic acid, but it doesn't happen just by mixing equimolar amounts of the two materials. The reaction is general acid- and base-catalysed, but is an equilibrium process which produces a mole of water as by-product. You have to have specialized equipment to continuously remove the ethyl acetate product from the higher-boiling water by distillation, or the reaction won't go to completion. Unless you're a chemical engineer or organic chemist with access to pilot plant equipment, you'll not be able to make much ethyl acetate on your own. (I'm an organic chemist by training, but I self-identify as a lepidopterist!)
jh
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Post by exoticimports on Feb 12, 2022 21:16:00 GMT -8
Lol John (DOCTOR John) I applaud you! You explained that in plain English! I often am a bit challenged to KISS.
So all, why would I change from rubbing alcohol to MEK in the field killing container?
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Post by LEPMAN on Feb 14, 2022 16:07:30 GMT -8
I have just read ethyl acetate occurs by the combination of acetic acid and ethanol. If that is the case what are the ratios so i can make my own. You can easily buy acetic acid in the form of white vinegar,and as i have a vintage motor bike that should not be run on E10 unleaded fuel i have built something to extract the ethanol from the petrol. As tempting as it may be to "try" and make Ethyl Acetate it can be difficult to produce due to the need for a reflux apparatus and distillation equipment (depending on your synthesis method) I have very rarely used EA, I bought 25ml a while back and still have most of it stored in sealed vials. Instead I have used chloroform since I was 16 with great success. Chloroform is very easy to make, you just stop by a pool supply store chlorine or pick up a gallon of concentrated bleach and a tin of acetone at your hardware store. Once you calculate your stoichiometry you can cool the gallon of bleach in the freezer and your acetone. This reaction is known as the haloform reaction and is basically a reaction between a keto methyl group and halogen gas (in this case NaOCl) to produce chloroform and sodium acetate. The sodium acetate stays in the water solution of the bleach and the chloroform liquid sinks to the bottom. The water can be easily decanted and the chloroform separated for use. I used to use bleach to make the chloroform to then add to my killing jar but now I opt for solid calcium hypochlorite in my jar. To recharge all I have to do is add a small amount of acetone. The reaction in the jar is exothermic so adding too much can cause a problem. Its also important to not forget the specimens in the jar too long otherwise they will turn beige or white as the chlorine reacts over time.
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Post by joniverson on Feb 16, 2022 4:36:46 GMT -8
Ok, so I picked up the Jasco brand from Lowe's. First test was the solute. I added it and the mix went well this time, unlike the acetone I tried prior. So, it will be usable in that regard. The odor certainly seems to confirm ethyl acetate. However, I don't like the metal container in which it is stored and may transfer it to something else. What sort of plastic container might be suitable? I'm thinking LDPE or HDPE for long term storage. Don't want to spend $ on such a container if I can find one for budget or repurposed cost. Thinking winshield washer fluid containers or ones used to store bleach. Any idea was type of plastic those use? I just checked my Chlorox bleach container.... HDPE. Maybe suitable for the ethyl acetate once cleaned out, but what about the lid?
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Jon D
Junior Member
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Post by Jon D on Feb 20, 2022 7:17:48 GMT -8
I was hoping one of the chemists would chime in here regarding the prior post (whether or not I can use an HDPE container for long term storage) but my own research into this suggests not, much to my surprise. So, I have come across a possible alternative: i.imgur.com/7yL4kON.jpgThis is a one gallon glass jug. Someone local has several at low cost and came from a wine maker. They are unused. However, they don't come with lids. While I would feel more confident of ethyl acetate's storage in this, the uncertainty of the lid negates that confidence. So, if I were to use this, what type of lid would I need? I believe this is the exact jug here:
Lids are shown below it, but not sure what size or even if suitable.
By the way, I don't trust storage in the can that it came in from Lowes. In the past, I have had similar acetone cans decay to the point where fluid was released. If I have no other choice, I'll keep it in the can and I'll just have to check on it every so often. Thanks in advance.
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Jon D
Junior Member
Posts: 22
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Post by Jon D on Feb 20, 2022 7:28:45 GMT -8
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Post by LEPMAN on Feb 20, 2022 8:42:17 GMT -8
in regards to your previous post, I keep my acetone in metal containers and it works fine. I assume it would be similar for ethyl acetate since it’s not corrosive. I imagine that the corrosion with ethyl acetate would be as a result of decomposition into acetic acid which is corrosive. My suggestion, grab a amber or tinted empty wine bottle and keep your ethyl acetate in it. There is no plastic and there is a reduced possibility of decay since the tint reduces the light effect on decomposition. Many lab storage bottles are tinted for light sensitive compounds. If you do use a clear glass container do some reading about EAs light sensitivity if you plan to store it long term. I also assume that your product must have some stabilizer in it to prevent decay.
Conclusion: use a wine bottle with a cork or metal lid.
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Post by LEPMAN on Feb 20, 2022 8:44:13 GMT -8
Also be aware that solvents like EA have a vapor pressure and evaporate easily and if you don’t have an airtight seal your EA will slowly disappear. Whatever you close your container with it should be able to maintain a positive vapor pressure inside the container.
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Jon D
Junior Member
Posts: 22
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Post by Jon D on Feb 20, 2022 9:13:00 GMT -8
All things considered, I think I'll just occasionally monitor the can it came in for now. I'm going to have trouble getting lids for the bottles at reasonable cost and it's not worth the 30+ mile drive to places that might have the lids. And they would cost more than the bottles!
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