Место издания:Institute of Low Temperature and Structure Research of the Polish Academy of Sciences. Mazowieckie Centrum Poligrafii Wroclav, Poland
Первая страница:138
Последняя страница:138
Аннотация:The chemical-physical properties (including the photo-/thermal stability, toxicity, and skin penetration efficiency) of polyethylene oxides (PEOs) and polypropylene oxides (PPOs) widely vary with the molecular weight Mw. Because of numerous vital applications in chemical, food, pharmaceutical, and cosmetic industries it is very important to be able to characterize the structure and state of these molecules in both the neat forms and in different composition and blends. We study PEOs with the average Mw from 400 Da to 10(7) Da and PPOs with the average Mw from 400 Da to 2000 Da. We found out that the number, peak positions, and intensities of the Raman lines of these substances are sensitive to the change in the molecular weight, the conformational composition and the degree of crystallinity. Our conclusions are also supported by the DFT calculations of Raman spectra of various conformers of low-molecular weight PEOs and PPOs.