β Scribed by Rossi, C. ;Magnasco, V.
No coin nor oath required. For personal study only.
Measurements of the limiting viscosity number and dipole moments in benzene at 25Β°C. have been performed on carefully fractionated low molecular weight poly(ethyleneoxide) (M.W. ranging from 194 to 7770). The results of these measurements have been related to some hypotheses on the structure of molecules in the dissolved state. We have realized that internal rotations of the bonds are hindered by asymmetric potentials with a minimum near the gauche position. Although the exact shape of these potentials has not yet been defined, the so deduced conformation of the molecule in solution agrees very well not only with our measurements, but also with the most probable hypotheses obtained from xβray studies on crystalline structure and infrared spectra of POEG in various physical states.
π SIMILAR VOLUMES
A number of results reported on the kinetics of exchange of triblock copolymers poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, between micelles and the intermicellar aqueous solution are reviewed and analyzed to extract the rate constants k(+) for the entry of a copoly