Forum Rules: Read This Before Posting


Topic: FTIR charts, what`s the material?  (Read 2787 times)

0 Members and 1 Guest are viewing this topic.

Offline zgryzik

  • New Member
  • **
  • Posts: 6
  • Mole Snacks: +0/-0
FTIR charts, what`s the material?
« on: October 27, 2018, 05:12:17 PM »
Hello!

I am new here. I have a huge problem, on my university I received two FTIR charts I think they`re some sort of polyamides, but I am not sure at all.
Is there any possibility for you to help me figuring out what those materials are?


1.https://ibb.co/nHd1Aq
2.https://ibb.co/djFRbV

I have also the DSC chart
for the 1st https://ibb.co/btoRAq
for the second  https://ibb.co/c2QpVq

Thank you so much!
« Last Edit: October 27, 2018, 05:31:09 PM by zgryzik »

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 1532
  • Mole Snacks: +219/-9
Re: FTIR charts, what`s the material?
« Reply #1 on: October 29, 2018, 06:57:38 AM »
You have to show an attempt at answering the question before receiving help, that's a forum rule. What do you think the spectra tell you?
Are these materials you have made yourself and got analysed, or are they some random spectra you were given as an exercise?

Offline zgryzik

  • New Member
  • **
  • Posts: 6
  • Mole Snacks: +0/-0
Re: FTIR charts, what`s the material?
« Reply #2 on: November 02, 2018, 04:43:54 AM »
The FTIR should tell me what my material is. The DSC shows the two peaks instead of one. That probabelly means, that it`s some sort of copolymer, or the first peak is caused by the fiber glass.
I receive this material on my studies and I have to diagnoze what is that.
I also burnt my material in order to compare it to other. The fire test of my material match the Polyamid almost 100%, but it doesnt burn outside of the flame (the clear polyamide burns).
So I guess, there is a lot of fire retardant inside.

https://tinypic.pl/trdq6icfaq28


I also found characteristic absorbtions of the IR, but I am not sure, how to use it properly...

http://www2.ups.edu/faculty/hanson/Spectroscopy/IR/IRfrequencies.html

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 1532
  • Mole Snacks: +219/-9
Re: FTIR charts, what`s the material?
« Reply #3 on: November 02, 2018, 05:44:25 AM »
You didn't say anything about fiberglass or fire retardant!
I think the first one is Nylon 6,6. (Google "Nylon 66 IR spectrum".) I'm not sure about the second, but 2299 suggests an isocyanate (not on your list!).

Offline zgryzik

  • New Member
  • **
  • Posts: 6
  • Mole Snacks: +0/-0
Re: FTIR charts, what`s the material?
« Reply #4 on: November 02, 2018, 01:33:06 PM »
Do You see any other characteristic peak on the second material FTIR? C-O? N-O?
« Last Edit: November 02, 2018, 02:10:44 PM by zgryzik »

Offline zgryzik

  • New Member
  • **
  • Posts: 6
  • Mole Snacks: +0/-0
Re: FTIR charts, what`s the material?
« Reply #5 on: November 09, 2018, 08:27:52 AM »
https://www.sciencedirect.com/science/article/pii/S0379711209000964?via%3Dihub

I found such article. Maybe my material is connected with the PBT, not PA as I thought?

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 1532
  • Mole Snacks: +219/-9
Re: FTIR charts, what`s the material?
« Reply #6 on: November 09, 2018, 11:12:18 AM »
PBT looks a good shot. It would fit most of the ir peaks except 2300, and also the DSC melting peak.

Offline zgryzik

  • New Member
  • **
  • Posts: 6
  • Mole Snacks: +0/-0
Re: FTIR charts, what`s the material?
« Reply #7 on: November 11, 2018, 04:29:00 AM »
What the 2300 peak might be? Cant find anything here :http://www2.ups.edu/faculty/hanson/Spectroscopy/IR/IRfrequencies.html

And the other  problem is : the melting point of PBT is about 220 while my material has 250. What might cause such difference? Glass fiber? Fire retardant?

Offline wildfyr

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 1153
  • Mole Snacks: +130/-9
Re: FTIR charts, what`s the material?
« Reply #8 on: November 11, 2018, 09:19:03 AM »
You sure 2300cm-1 isn't O2 from the air? Happens when someone is breathing nearby as it's poorly backgrounded

Offline zgryzik

  • New Member
  • **
  • Posts: 6
  • Mole Snacks: +0/-0
Re: FTIR charts, what`s the material?
« Reply #9 on: November 11, 2018, 03:50:02 PM »
Do You think so, Sir?

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 1532
  • Mole Snacks: +219/-9
Re: FTIR charts, what`s the material?
« Reply #10 on: November 12, 2018, 07:27:30 AM »
O2 in infrared?
Frequency is reported as 2061 (Raman).
Sample 2 melts at about 220°C. I'm thinking sample 1 is Nylon 6,6 and sample 2 is PBT. Or are you saying they are related (e.g. one is a precursor or decomposition product of the other)?

Offline wildfyr

  • Global Moderator
  • Sr. Member
  • ***
  • Posts: 1153
  • Mole Snacks: +130/-9
Re: FTIR charts, what`s the material?
« Reply #11 on: November 12, 2018, 10:06:11 AM »
Oooooops I meant co2

Sponsored Links