Dear Mohammed Bakir , elemental analysis of PEO and ethylene oxide should show the same elemental composition, C, H and O, but their relationship is different. For ethylene oxide it should be C2H4O while for PEO it should be C2nH4n+2On+1.

Hope it helps.

Dear all, if we consider PEO with the following structure : HO-(-CH2-CH2-O-)n-H, I think the summation given by Dr. Manuel Gómez should be adjusted to the following : 2nC+(4n+2)H+(n+1)O. I think there will be a slight difference due the difference in the decomposition kinetics between a polymer and a small molecule. In addition to that, the slight contribution to the mass by the PEO end groups. Also to consider the effect of possible existence of branches. My Regards

Hi;

I agree completely with Dr. A. BOUAZIZ

The general formula of PEO is H(OCH2CH2)nOH , which corresponds to C2nH4n+On+1.

With my best regards

Dear Mohammed Bakir thank you for your interesting technical question. I fully agree with the helpful answers provided by Manuel Gómez, Abdelkader BOUAZIZ and Doufnoune RACHIDA Rachida especially with respect to the general structure of PEO (see attached schematic formula drawing). What i would like to add is the following: As shown in the attached link, PEO is normally sold with molecular weights in the range between ca. 400 and 4,000,000. Even with n = 400 in the general formula, the two additional hydrogen atoms at the ends do not really count any more. In other words, the higher the molecular weight of your PEO, the more is the C,N,N analysis of the sample identical with that of the monomer ethylene oxide.

https://www.sigmaaldrich.com/catalog/product/aldrich/181986?lang=de®ion=DE