The ratio of the unperturbed mean-square end-to-end distance to the molecular weight in the random-coil limit, ((R2)0f/m) in the freerotation approximation was calculated for chains of linear polyurethanes PUR-DI: prepared from 4,4’-methylenediphenyl diisocyanates and low-molecular-weight diols HO-(CH2)k-OH (k = 2, 3, 4 and 6). It was found that the experimental values of (R2)0f/m), estimated in the previous paper are very close to the values of (R2)0f/m), calculated under the assumption that the groups of bonds CH2-C&-NH NH-CO-0-CH2 can be replaced by rigid virtual bonds.
Посилання на статтю:
Free-rotation dimensions of some polyurethane chains / Jiri Dostila, Lubomir Simek, Miloslav Bohdanecy // Polymer. – 1999. – N 40. – P. 613–616.