Carbon Black/epoxy degradation in NaOH

[hamG]

hai there, can any1 tell me what has happen in the picture attached? The material used is Carbon Black filler/epoxy immerse into 2wt.% NaOH for corrosion test using tafel, 7mv/s scan rate is used.

CB filler used is electrical type, come in large fibre and milled to micro size.

CB is indicate by a straight long fibre at the lower right.

Is there a reaction between NaOH and CB cause this? I seem can't find it anywhere in the website and book

 

[CoryPad]

The file you attached is a Scanning Electron Microscope image. That is too high of magnification to begin this conversation. How about a non-magnified photograph of the part or preform or whatever state these materials are in before and after the test. Speaking of the materials, how were they processed? Was the carbon black added to liquid epoxy which was then cured by adding a hardener or exposed to heat, UV, something else? We would need more basic information to provide help to you.

 

[hamG]

well here i attached with the lower magnification/ before and after immerse into NaOH. pls bear in mind the image is of different specimens and it is polished before the test is conducted and you can see at the middle of the image which is the same as i send before

this is how they processed, the carbon black is mixed with liquid epoxy then was cured with amine.

finally it was used in potentiostat

it doesn't exposed to any other condition like uv and heat.
the epoxy and hardener used is 10 part to 1 part.

file name carbon black a ; is before immerse into NaOH
file name cb NaOH1 is after immersion in NaOH solutions

it doesn't seem to occur in NaCl and HCl solutions. is it possible this is due to the curing process?