I've got several samples of the same polymer and have reacted them with different plasticisers. On the NMR of all the samples but one, the peaks that I expect to be present in everything are roughly the same width, however for one of the samples, these very same peaks are significantly wider. Is there any reason behind this?
Mark Andrews
You do not write what NMR spectra of hydrogen or other elements you have. The width of the peaks together with the change in area indicates interaction with the plasticizer. If the peaks are protons, then the increase in width (area under the peak) shows the interaction of the polymer proton with the acceptor group of the plasticizer.
Yuri Mirgorod thank you for your reply. And yes it is proton NMR, my apologies for forgetting to add that.
So for example, if I had a peak width of 20 for the base polymer, 30 for the polymer with plasticiser A and 40 for the polymer with plasticiser B (these are all made up values for arguments sake), would it be fair to assume that plasticiser B has stronger interactions with the polymer than plasticiser A?
Mark Andrews
Yes, if the peak is related to a hydrogen bond. Then you have more hydrogen bonds. Again, not the width, but the area under the peak.