In general understanding GNP reinforcement increases thermal stability of epoxy nanocomposites, my materials thermal stability is decreasing, what might be the possible explanation?
GNP ,amine functionalized using a Dielectric Barrier Discharge process by supplier, dispersion method ultrasonication 45% amplitude and 3 roll shear mixing.
I doubt sonication is having an effcect on the GNP?
with amine as the modifier, first check the stability of the modified nanoparticles at the processing temperature using TGA. Amine being an organic modifier might degrade at the processing temperature which you have not mentioned here.
If this is eliminated then probable reason could be sonication
Dear Zaheeruddin Mohammed
As Mentioned by Sarita Charde above, modification of your GNP may alter the thermal stabilit of the GNP. Sonication can reduce the size of your GNP. Especially if you sonicate for long periods. I have observed this i one of my experiments when dispersing graphene in epoxy resins.
Kind regards
Louis van Rooyen
Why does modification decrease the thermal stability can you explain the reason behind it. thanks.
Dear Zaheerudin
This may be due to a couple of things. It could indicate that your functionalised graphene might not be reacting/crosslinking with your epoxy. Hence, no thermal improvement. Also, the functionalisation of graphene forms sp3 type bonds due to the sp2 carbon structured being altered. This can alter your thermal stability of your functionalised graphene compared to the pristine graphene. A similar effect has been observed with GO and polyurethane. Here is the reference: R.M. Hodlur, M.K. Rabinal, Self assembled graphene layers on polyurethane foam as a highly pressure sensitive conducting composite, Compos. Sci. Technol. 90 (2014) 160–165.
I hope this info helps. I would recommend that you maybe perform TGA on the GNP and functionalised GNP to compare the thermal stability of the 2 fillers as also suggested by Sarita Charde. This will be useful to confirm if this is the case. Please do feel free to contact me anytime.
Regards
Louis
Hello Zaheerudin,
Have you think about the growth of thermal conductivity by compositing a polymer with graphene or graphene oxide? That leads to a faster degradation but no in a less temperature.
That is the effect I get when made some graphene based polymer composites in our lab.
Hi Mr.Acevedo
I am working with just fuctionalized graphene, not graphene oxide. I could not understand your answer, "that leads to faster degradation but no in less temperature" can you please elaborate. thanks.
Thanks Mr.Rooyen and Miss.Charde
thanks for your suggestions i will look at the thermal stability of fillers themselves and see what is happening.thanks again.
Hello Zaheeruddin,
Sorry I didn't made me understand, what I was trying to say is that heat flows faster through the composite because of thermal conductivity of graphene. That is a phenomena I always look when making polymer composites and depending on the relation polymer matrix/reinforcement. So graphene acts like hot spots inside the polymer.
Do not hesitate in asking again, so I can tell you more about my experiences.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Carbon Materials
- Graphite
- Graphene