Testing for Ethylene Glycol Layer on PMMA Experiment

  • Thread starter dacruick
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In summary, the researcher is trying to make a mould out of a PMMA using a resin containing Epichlorohydrin and ethylene oxide. They are unsure of chemistry, but they have done some research and they believe that ethylene oxide can react with water to produce glycol. It is possible that there was enough water absorbed into the PMMA that the ethylene oxide reacted with it and formed a layer of glycol at the top. The researcher is also concerned about the test because they think the bubbles are small and they don't think they will be able to scavenge enough of the glycol to create a flame that is green.
  • #1
dacruick
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Hi

I am doing an experiment right now trying to make a mould out of a poly methyl methacrylate (PMMA) using a resin containing Epichlorohydrin and ethylene oxide.

I do not know very much about chemistry but through some research I see that ethylene oxide can react with water to produce glycol. I also hear that PMMA can absorb water.

Is it possible that there was enough water absorbed into the PMMA that the ethylene oxide reacted with it and formed a layer of glycol at the top?

And my big question is, is there any easy way to test if the layer is ethylene glycol?

Thanks a bunch

dacruick
 
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  • #2
Ethylene glycol is soluble in water in all proportions. Epichlorohydrin is slightly soluble.

If you have a copper wire, pass it through a hot flame (blue flame from bunsen burner) and when cool, dip it into the liquid. Put that back into the flame and look for green. Green signifies chlorine and means that you have at least some epi in that sample. http://www.sha.org/research_resources/conservation_faqs/documents/beilstei.pdf"
 
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  • #3
I will try that. But to clarify, I do not have any water (or at least no water that I meant to have), in the resin. It was simply the resin and the acrylic only.

originally I had the ethylene oxide and the epichlorohydrin, then I mixed in Triethylenetetramine which is the hardener for the resin. It has now completely cured and is a solid block of this resin, but with an oily substance on the top.

bubbles have formed of this oily substance and if I had to guess, I would guess it is glycol.

Thank you for your help, and in advance for any future help:).

Oh P.S

The bubbles are very small, I am concerned that I won't be able to scavenge enough of it to create a flame that is green.
 
  • #4
Don't worry, it's a very sensitive test.
 
  • #5
shank

Hello dacruickshank,

Thank you for sharing your experiment with us. It's great to see you taking an interest in chemistry and conducting your own experiments. Let me address your questions one by one.

Firstly, it is possible for ethylene oxide to react with water to produce glycol. This is known as the ethylene glycol hydrolysis reaction and is commonly used in the production of ethylene glycol. However, in your experiment, you are using a resin containing both epichlorohydrin and ethylene oxide, so it is unlikely that there will be a significant amount of ethylene oxide available to react with water and produce glycol. Additionally, PMMA is not known to readily absorb water, so it is unlikely that the ethylene oxide would react with any water present in the PMMA to form glycol.

To test for the presence of ethylene glycol, there are a few options you can consider. One simple method is to use a pH strip to test the pH of the layer. Ethylene glycol has a pH of around 7, so if the layer is acidic or basic, it is not likely to be ethylene glycol. Another method is to use gas chromatography-mass spectrometry (GC-MS) to analyze the composition of the layer. This technique can accurately identify the presence of ethylene glycol and other substances in the layer. However, this method may require specialized equipment and training.

In conclusion, it is unlikely that the layer on top of your PMMA is ethylene glycol. I suggest conducting some further tests to determine the composition of the layer. Good luck with your experiment!
 

FAQ: Testing for Ethylene Glycol Layer on PMMA Experiment

1. What is the purpose of the "Testing for Ethylene Glycol Layer on PMMA Experiment"?

The purpose of this experiment is to determine the presence and thickness of an ethylene glycol layer on a PMMA (polymethylmethacrylate) surface. This layer can affect the properties and performance of PMMA, so it is important to accurately detect and measure its thickness.

2. How is the ethylene glycol layer on PMMA detected in this experiment?

The ethylene glycol layer is detected using Fourier transform infrared spectroscopy (FTIR). This technique measures the absorption of infrared light by the chemical bonds in the ethylene glycol layer, allowing for its identification and quantification.

3. What are the steps involved in this experiment?

The experiment involves preparing a PMMA sample with a known thickness, exposing it to ethylene glycol vapor, and then analyzing the sample using FTIR. The resulting spectra are then compared to a control sample to determine the presence and thickness of the ethylene glycol layer.

4. What are the potential sources of error in this experiment?

Potential sources of error include contamination of the PMMA sample, variations in temperature and humidity during exposure to ethylene glycol vapor, and instrumental error in the FTIR analysis. It is important to carefully control and monitor these factors to ensure accurate results.

5. How can the results of this experiment be used in practical applications?

The results of this experiment can be used to optimize the manufacturing process of PMMA products, as well as to ensure the quality and performance of these products. It can also be used in research to study the effects of ethylene glycol on PMMA and to explore potential applications of this combination.

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