Sunday, October 10, 2010

Composite Compatability tests.


I soaked 8 composite samples in 85% peroxide for about 5 hours at 70F.
Top Row:
  • Epoxy with no fiber
  • Glass fiber in epoxy
  • Kevlar in Epoxy
  • Carbon in Epoxy
Bottom Row: Vipel 010 Chemically resistant vinyl ester
  • Vipel Resin no fiber
  • Glass fiber with vipel
  • Kevlar with Vipel
  • Carbon Fiber with Vipel.
Experimental setup.
I set out 6 polyethylene cups with 300ml of 85% H2O2.
I tied polyester cord to each sample and placed them in the H2O2 solution.
They were placed so 75% of the sample was covered.
The Pure resin and glass fiber samples with the same resin shared a cup.
I put a clear polyethylene bag over each cup.
I periodically observed the samples.
I left them in the sun for ~5 hours.


The bags of 4 of the sample cups were clear, the bags over the two carbon fiber samples has fogged condensation on the inside of the bag. This seems to indicate some H2O2 decomposition.
It was not enough to measure any significant volume change.
None of the samples had shown any significant h2o2 decomposition. They were filled to 300ml +/-10ml and at the end they were all 300ml +/- 10ml.

I then removed the bags off the top of each cup with a long set of tongs.

After the 5 hours I was hesitant to handle the sample or move the containers as I was possible I'd created a hazardous solution. So I could not weight the samples.

After 5 hours the epoxy samples all had a layer of something floating on the top of the H2O2.
The Vipel samples had no visible contamination of the h2O2.

Then one by one for each sample (except the pure resins)
  • I grabbed the loose cord tied to each sample with the tongs, carried them over the the wire fence and hung them on the fence.
  • I then shot the sample with a 243 winchester with 85gr bullets from about 25 ft away. The impact velocity was 900 to 1000 m/sec.
None of the samples showed any sign of detonation or any increase in energy release from the rifle shot. I did not shoot the pure resin as I expected the pure resin would shatter and not provide any additional information.

After determining that none of the samples detonated I then individually dumped each h2O2 container on the dirt. (Mojave dirt is a great decomposition catalyst.) No notable difference in energy or release was noted.

I then removed each sample from the fence and soaked them in water to remove the peroxide.
The samples are shown in the picture above. The Vipel samples showed some surface etching, ie they had an oxide layer on the surface, but showed no significant structural degradation.
The epoxy samples wer reduced to bare fiber. There was almost no structure left.

In the picture both bare resins look discolored, but the Epoxy is bubbled and distored, where the layer on the vipel is just a surface layer its very thin. It almost looks like the oxide layer aluminum gets after a lot of peroxide exposure.

The company that makes the vipel F010 has an even more resistant resin, K190 that is harder to get. The K190 is rated for 50% peroxide at 100F for years of service.
Their chemical compatibility guide

When I'd finished pouring out the peroxide in the 6 cups I had a 100 ml or so left in my transfer cup. So I put a bunch of raw kevlar with no resin in that cup. It had ZERO reaction of any kind, no bubbles, no discoloration, no steam on the bag etc...

5 comments:

Anonymous said...

I can confirm your epoxy observations as I had the same experiance in the design of a 6.5 gal 85% peroxide tank. I used a 6.1inch fiberglass tube and lined it with poly. On the first tank made we used epoxy to make some seals and hold certain componets in place. All the epoxy that came in contact with the peroxide was eaten away over a period of several hours. Needless to say, we are now using a different method to make the seals.

Eraser3000 said...

Very thorough. Thanks for sharing.

Unknown said...

I agree with this post, since I have a product on résine epoxy not totally the same as yours but I can see your experiment totally make sense to me, and I think I am going to add this product to my business.

Tatvachintan said...

the same experiance in the design of a 6.5 gal 85% peroxide tank. I used a 6.1inch fiberglass tube and lined it with poly and Epoxy Zeolite Curing Catalysts. Thanks!

jhon said...

in the application of the collection of wood materials and plastic excellent features. We know that in the use of solid wood products in certain home fence installation